From a953e4597abd51b74c99e0e3b7074532a60fd031 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:12 +0200 Subject: sched: replace MAX_NUMNODES with nr_node_ids in kernel/sched.c * Replace usages of MAX_NUMNODES with nr_node_ids in kernel/sched.c, where appropriate. This saves some allocated space as well as many wasted cycles going through node entries that are non-existent. For inclusion into sched-devel/latest tree. Based on: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6.git + sched-devel/latest .../mingo/linux-2.6-sched-devel.git Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar --- kernel/sched.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index cfa222a9153..1ed8011db82 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6879,9 +6879,9 @@ static int find_next_best_node(int node, nodemask_t *used_nodes) min_val = INT_MAX; - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { /* Start at @node */ - n = (node + i) % MAX_NUMNODES; + n = (node + i) % nr_node_ids; if (!nr_cpus_node(n)) continue; @@ -7075,7 +7075,7 @@ static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) if (!sched_group_nodes) continue; - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { struct sched_group *oldsg, *sg = sched_group_nodes[i]; *nodemask = node_to_cpumask(i); @@ -7263,7 +7263,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* * Allocate the per-node list of sched groups */ - sched_group_nodes = kcalloc(MAX_NUMNODES, sizeof(struct sched_group *), + sched_group_nodes = kcalloc(nr_node_ids, sizeof(struct sched_group *), GFP_KERNEL); if (!sched_group_nodes) { printk(KERN_WARNING "Can not alloc sched group node list\n"); @@ -7407,7 +7407,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #endif /* Set up physical groups */ - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { SCHED_CPUMASK_VAR(nodemask, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7431,7 +7431,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, send_covered, tmpmask); } - for (i = 0; i < MAX_NUMNODES; i++) { + for (i = 0; i < nr_node_ids; i++) { /* Set up node groups */ struct sched_group *sg, *prev; SCHED_CPUMASK_VAR(nodemask, allmasks); @@ -7470,9 +7470,9 @@ static int __build_sched_domains(const cpumask_t *cpu_map, cpus_or(*covered, *covered, *nodemask); prev = sg; - for (j = 0; j < MAX_NUMNODES; j++) { + for (j = 0; j < nr_node_ids; j++) { SCHED_CPUMASK_VAR(notcovered, allmasks); - int n = (i + j) % MAX_NUMNODES; + int n = (i + j) % nr_node_ids; node_to_cpumask_ptr(pnodemask, n); cpus_complement(*notcovered, *covered); @@ -7525,7 +7525,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, } #ifdef CONFIG_NUMA - for (i = 0; i < MAX_NUMNODES; i++) + for (i = 0; i < nr_node_ids; i++) init_numa_sched_groups_power(sched_group_nodes[i]); if (sd_allnodes) { -- cgit v1.2.3 From 363ab6f1424cdea63e5d182312d60e19077b892a Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:13 +0200 Subject: core: use performance variant for_each_cpu_mask_nr Change references from for_each_cpu_mask to for_each_cpu_mask_nr where appropriate Reviewed-by: Paul Jackson Reviewed-by: Christoph Lameter Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/cpu.c | 2 +- kernel/rcuclassic.c | 2 +- kernel/rcupreempt.c | 10 +++++----- kernel/sched.c | 36 ++++++++++++++++++------------------ kernel/sched_fair.c | 2 +- kernel/sched_rt.c | 6 +++--- kernel/taskstats.c | 4 ++-- kernel/workqueue.c | 6 +++--- 8 files changed, 34 insertions(+), 34 deletions(-) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index c77bc3a1c72..50ae922c602 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -390,7 +390,7 @@ void __ref enable_nonboot_cpus(void) goto out; printk("Enabling non-boot CPUs ...\n"); - for_each_cpu_mask(cpu, frozen_cpus) { + for_each_cpu_mask_nr(cpu, frozen_cpus) { error = _cpu_up(cpu, 1); if (!error) { printk("CPU%d is up\n", cpu); diff --git a/kernel/rcuclassic.c b/kernel/rcuclassic.c index f4ffbd0f306..251358de70b 100644 --- a/kernel/rcuclassic.c +++ b/kernel/rcuclassic.c @@ -92,7 +92,7 @@ static void force_quiescent_state(struct rcu_data *rdp, */ cpumask = rcp->cpumask; cpu_clear(rdp->cpu, cpumask); - for_each_cpu_mask(cpu, cpumask) + for_each_cpu_mask_nr(cpu, cpumask) smp_send_reschedule(cpu); } } diff --git a/kernel/rcupreempt.c b/kernel/rcupreempt.c index e1cdf196a51..18af270125c 100644 --- a/kernel/rcupreempt.c +++ b/kernel/rcupreempt.c @@ -657,7 +657,7 @@ rcu_try_flip_idle(void) /* Now ask each CPU for acknowledgement of the flip. */ - for_each_cpu_mask(cpu, rcu_cpu_online_map) { + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) { per_cpu(rcu_flip_flag, cpu) = rcu_flipped; dyntick_save_progress_counter(cpu); } @@ -675,7 +675,7 @@ rcu_try_flip_waitack(void) int cpu; RCU_TRACE_ME(rcupreempt_trace_try_flip_a1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) if (rcu_try_flip_waitack_needed(cpu) && per_cpu(rcu_flip_flag, cpu) != rcu_flip_seen) { RCU_TRACE_ME(rcupreempt_trace_try_flip_ae1); @@ -707,7 +707,7 @@ rcu_try_flip_waitzero(void) /* Check to see if the sum of the "last" counters is zero. */ RCU_TRACE_ME(rcupreempt_trace_try_flip_z1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) sum += RCU_DATA_CPU(cpu)->rcu_flipctr[lastidx]; if (sum != 0) { RCU_TRACE_ME(rcupreempt_trace_try_flip_ze1); @@ -722,7 +722,7 @@ rcu_try_flip_waitzero(void) smp_mb(); /* ^^^^^^^^^^^^ */ /* Call for a memory barrier from each CPU. */ - for_each_cpu_mask(cpu, rcu_cpu_online_map) { + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) { per_cpu(rcu_mb_flag, cpu) = rcu_mb_needed; dyntick_save_progress_counter(cpu); } @@ -742,7 +742,7 @@ rcu_try_flip_waitmb(void) int cpu; RCU_TRACE_ME(rcupreempt_trace_try_flip_m1); - for_each_cpu_mask(cpu, rcu_cpu_online_map) + for_each_cpu_mask_nr(cpu, rcu_cpu_online_map) if (rcu_try_flip_waitmb_needed(cpu) && per_cpu(rcu_mb_flag, cpu) != rcu_mb_done) { RCU_TRACE_ME(rcupreempt_trace_try_flip_me1); diff --git a/kernel/sched.c b/kernel/sched.c index 1ed8011db82..814d6e17f1e 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2271,7 +2271,7 @@ find_idlest_group(struct sched_domain *sd, struct task_struct *p, int this_cpu) /* Tally up the load of all CPUs in the group */ avg_load = 0; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { /* Bias balancing toward cpus of our domain */ if (local_group) load = source_load(i, load_idx); @@ -2313,7 +2313,7 @@ find_idlest_cpu(struct sched_group *group, struct task_struct *p, int this_cpu, /* Traverse only the allowed CPUs */ cpus_and(*tmp, group->cpumask, p->cpus_allowed); - for_each_cpu_mask(i, *tmp) { + for_each_cpu_mask_nr(i, *tmp) { load = weighted_cpuload(i); if (load < min_load || (load == min_load && i == this_cpu)) { @@ -3296,7 +3296,7 @@ find_busiest_group(struct sched_domain *sd, int this_cpu, max_cpu_load = 0; min_cpu_load = ~0UL; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { struct rq *rq; if (!cpu_isset(i, *cpus)) @@ -3560,7 +3560,7 @@ find_busiest_queue(struct sched_group *group, enum cpu_idle_type idle, unsigned long max_load = 0; int i; - for_each_cpu_mask(i, group->cpumask) { + for_each_cpu_mask_nr(i, group->cpumask) { unsigned long wl; if (!cpu_isset(i, *cpus)) @@ -4100,7 +4100,7 @@ static void run_rebalance_domains(struct softirq_action *h) int balance_cpu; cpu_clear(this_cpu, cpus); - for_each_cpu_mask(balance_cpu, cpus) { + for_each_cpu_mask_nr(balance_cpu, cpus) { /* * If this cpu gets work to do, stop the load balancing * work being done for other cpus. Next load @@ -6832,7 +6832,7 @@ init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map, cpus_clear(*covered); - for_each_cpu_mask(i, *span) { + for_each_cpu_mask_nr(i, *span) { struct sched_group *sg; int group = group_fn(i, cpu_map, &sg, tmpmask); int j; @@ -6843,7 +6843,7 @@ init_sched_build_groups(const cpumask_t *span, const cpumask_t *cpu_map, cpus_clear(sg->cpumask); sg->__cpu_power = 0; - for_each_cpu_mask(j, *span) { + for_each_cpu_mask_nr(j, *span) { if (group_fn(j, cpu_map, NULL, tmpmask) != group) continue; @@ -7043,7 +7043,7 @@ static void init_numa_sched_groups_power(struct sched_group *group_head) if (!sg) return; do { - for_each_cpu_mask(j, sg->cpumask) { + for_each_cpu_mask_nr(j, sg->cpumask) { struct sched_domain *sd; sd = &per_cpu(phys_domains, j); @@ -7068,7 +7068,7 @@ static void free_sched_groups(const cpumask_t *cpu_map, cpumask_t *nodemask) { int cpu, i; - for_each_cpu_mask(cpu, *cpu_map) { + for_each_cpu_mask_nr(cpu, *cpu_map) { struct sched_group **sched_group_nodes = sched_group_nodes_bycpu[cpu]; @@ -7302,7 +7302,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* * Set up domains for cpus specified by the cpu_map. */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = NULL, *p; SCHED_CPUMASK_VAR(nodemask, allmasks); @@ -7374,7 +7374,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #ifdef CONFIG_SCHED_SMT /* Set up CPU (sibling) groups */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { SCHED_CPUMASK_VAR(this_sibling_map, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7391,7 +7391,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #ifdef CONFIG_SCHED_MC /* Set up multi-core groups */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { SCHED_CPUMASK_VAR(this_core_map, allmasks); SCHED_CPUMASK_VAR(send_covered, allmasks); @@ -7458,7 +7458,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, goto error; } sched_group_nodes[i] = sg; - for_each_cpu_mask(j, *nodemask) { + for_each_cpu_mask_nr(j, *nodemask) { struct sched_domain *sd; sd = &per_cpu(node_domains, j); @@ -7504,21 +7504,21 @@ static int __build_sched_domains(const cpumask_t *cpu_map, /* Calculate CPU power for physical packages and nodes */ #ifdef CONFIG_SCHED_SMT - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(cpu_domains, i); init_sched_groups_power(i, sd); } #endif #ifdef CONFIG_SCHED_MC - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(core_domains, i); init_sched_groups_power(i, sd); } #endif - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd = &per_cpu(phys_domains, i); init_sched_groups_power(i, sd); @@ -7538,7 +7538,7 @@ static int __build_sched_domains(const cpumask_t *cpu_map, #endif /* Attach the domains */ - for_each_cpu_mask(i, *cpu_map) { + for_each_cpu_mask_nr(i, *cpu_map) { struct sched_domain *sd; #ifdef CONFIG_SCHED_SMT sd = &per_cpu(cpu_domains, i); @@ -7621,7 +7621,7 @@ static void detach_destroy_domains(const cpumask_t *cpu_map) unregister_sched_domain_sysctl(); - for_each_cpu_mask(i, *cpu_map) + for_each_cpu_mask_nr(i, *cpu_map) cpu_attach_domain(NULL, &def_root_domain, i); synchronize_sched(); arch_destroy_sched_domains(cpu_map, &tmpmask); diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index e24ecd39c4b..e398318f101 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1022,7 +1022,7 @@ static int wake_idle(int cpu, struct task_struct *p) || ((sd->flags & SD_WAKE_IDLE_FAR) && !task_hot(p, task_rq(p)->clock, sd))) { cpus_and(tmp, sd->span, p->cpus_allowed); - for_each_cpu_mask(i, tmp) { + for_each_cpu_mask_nr(i, tmp) { if (idle_cpu(i)) { if (i != task_cpu(p)) { schedstat_inc(p, diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 060e87b0cb1..d73386c6e36 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -231,7 +231,7 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun) return 1; span = sched_rt_period_mask(); - for_each_cpu_mask(i, span) { + for_each_cpu_mask_nr(i, span) { int enqueue = 0; struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i); struct rq *rq = rq_of_rt_rq(rt_rq); @@ -272,7 +272,7 @@ static int balance_runtime(struct rt_rq *rt_rq) spin_lock(&rt_b->rt_runtime_lock); rt_period = ktime_to_ns(rt_b->rt_period); - for_each_cpu_mask(i, rd->span) { + for_each_cpu_mask_nr(i, rd->span) { struct rt_rq *iter = sched_rt_period_rt_rq(rt_b, i); s64 diff; @@ -1000,7 +1000,7 @@ static int pull_rt_task(struct rq *this_rq) next = pick_next_task_rt(this_rq); - for_each_cpu_mask(cpu, this_rq->rd->rto_mask) { + for_each_cpu_mask_nr(cpu, this_rq->rd->rto_mask) { if (this_cpu == cpu) continue; diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 4a23517169a..06b17547f4e 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -301,7 +301,7 @@ static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) return -EINVAL; if (isadd == REGISTER) { - for_each_cpu_mask(cpu, mask) { + for_each_cpu_mask_nr(cpu, mask) { s = kmalloc_node(sizeof(struct listener), GFP_KERNEL, cpu_to_node(cpu)); if (!s) @@ -320,7 +320,7 @@ static int add_del_listener(pid_t pid, cpumask_t *maskp, int isadd) /* Deregister or cleanup */ cleanup: - for_each_cpu_mask(cpu, mask) { + for_each_cpu_mask_nr(cpu, mask) { listeners = &per_cpu(listener_array, cpu); down_write(&listeners->sem); list_for_each_entry_safe(s, tmp, &listeners->list, list) { diff --git a/kernel/workqueue.c b/kernel/workqueue.c index 29fc39f1029..28c2b2c96ac 100644 --- a/kernel/workqueue.c +++ b/kernel/workqueue.c @@ -397,7 +397,7 @@ void flush_workqueue(struct workqueue_struct *wq) might_sleep(); lock_acquire(&wq->lockdep_map, 0, 0, 0, 2, _THIS_IP_); lock_release(&wq->lockdep_map, 1, _THIS_IP_); - for_each_cpu_mask(cpu, *cpu_map) + for_each_cpu_mask_nr(cpu, *cpu_map) flush_cpu_workqueue(per_cpu_ptr(wq->cpu_wq, cpu)); } EXPORT_SYMBOL_GPL(flush_workqueue); @@ -477,7 +477,7 @@ static void wait_on_work(struct work_struct *work) wq = cwq->wq; cpu_map = wq_cpu_map(wq); - for_each_cpu_mask(cpu, *cpu_map) + for_each_cpu_mask_nr(cpu, *cpu_map) wait_on_cpu_work(per_cpu_ptr(wq->cpu_wq, cpu), work); } @@ -813,7 +813,7 @@ void destroy_workqueue(struct workqueue_struct *wq) list_del(&wq->list); spin_unlock(&workqueue_lock); - for_each_cpu_mask(cpu, *cpu_map) + for_each_cpu_mask_nr(cpu, *cpu_map) cleanup_workqueue_thread(per_cpu_ptr(wq->cpu_wq, cpu)); put_online_cpus(); -- cgit v1.2.3 From cad0e458d17c643c20c1d38f45a1d26125e6a622 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Mon, 12 May 2008 21:21:13 +0200 Subject: clocksource/events: use performance variant for_each_cpu_mask_nr Change references from for_each_cpu_mask to for_each_cpu_mask_nr where appropriate Reviewed-by: Paul Jackson Reviewed-by: Christoph Lameter Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/time/clocksource.c | 4 ++-- kernel/time/tick-broadcast.c | 3 +-- 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index dadde5361f3..60ceabd53f2 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -145,9 +145,9 @@ static void clocksource_watchdog(unsigned long data) * Cycle through CPUs to check if the CPUs stay * synchronized to each other. */ - int next_cpu = next_cpu(raw_smp_processor_id(), cpu_online_map); + int next_cpu = next_cpu_nr(raw_smp_processor_id(), cpu_online_map); - if (next_cpu >= NR_CPUS) + if (next_cpu >= nr_cpu_ids) next_cpu = first_cpu(cpu_online_map); watchdog_timer.expires += WATCHDOG_INTERVAL; add_timer_on(&watchdog_timer, next_cpu); diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 57a1f02e5ec..2d0a9634625 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -397,8 +397,7 @@ again: mask = CPU_MASK_NONE; now = ktime_get(); /* Find all expired events */ - for (cpu = first_cpu(tick_broadcast_oneshot_mask); cpu != NR_CPUS; - cpu = next_cpu(cpu, tick_broadcast_oneshot_mask)) { + for_each_cpu_mask_nr(cpu, tick_broadcast_oneshot_mask) { td = &per_cpu(tick_cpu_device, cpu); if (td->evtdev->next_event.tv64 <= now.tv64) cpu_set(cpu, mask); -- cgit v1.2.3 From 9c44bc03fff44ff04237a7d92e35304a0e50c331 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:21:04 +0200 Subject: softlockup: allow panic on lockup allow users to configure the softlockup detector to generate a panic instead of a warning message. high-availability systems might opt for this strict method (combined with panic_timeout= boot option/sysctl), instead of generating softlockup warnings ad infinitum. also, automated tests work better if the system reboots reliably (into a safe kernel) in case of a lockup. The full spectrum of configurability is supported: boot option, sysctl option and Kconfig option. it's default-disabled. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/softlockup.c | 21 +++++++++++++++++++++ kernel/sysctl.c | 11 +++++++++++ 2 files changed, 32 insertions(+) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 01b6522fd92..78e0ad21cb0 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -27,6 +27,21 @@ static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int __read_mostly did_panic; unsigned long __read_mostly softlockup_thresh = 60; +/* + * Should we panic (and reboot, if panic_timeout= is set) when a + * soft-lockup occurs: + */ +unsigned int __read_mostly softlockup_panic = + CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC_VALUE; + +static int __init softlockup_panic_setup(char *str) +{ + softlockup_panic = simple_strtoul(str, NULL, 0); + + return 1; +} +__setup("softlockup_panic=", softlockup_panic_setup); + static int softlock_panic(struct notifier_block *this, unsigned long event, void *ptr) { @@ -120,6 +135,9 @@ void softlockup_tick(void) else dump_stack(); spin_unlock(&print_lock); + + if (softlockup_panic) + panic("softlockup: hung tasks"); } /* @@ -172,6 +190,9 @@ static void check_hung_task(struct task_struct *t, unsigned long now) t->last_switch_timestamp = now; touch_nmi_watchdog(); + + if (softlockup_panic) + panic("softlockup: blocked tasks"); } /* diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 29116652dca..2d3b388c402 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -727,6 +727,17 @@ static struct ctl_table kern_table[] = { }, #endif #ifdef CONFIG_DETECT_SOFTLOCKUP + { + .ctl_name = CTL_UNNUMBERED, + .procname = "softlockup_panic", + .data = &softlockup_panic, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = &proc_doulongvec_minmax, + .strategy = &sysctl_intvec, + .extra1 = &zero, + .extra2 = &one, + }, { .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", -- cgit v1.2.3 From 9383d9679056e6cc4e7ff70f31da945a268238f4 Mon Sep 17 00:00:00 2001 From: Dimitri Sivanich Date: Mon, 12 May 2008 21:21:14 +0200 Subject: softlockup: fix softlockup_thresh unaligned access and disable detection at runtime Fix unaligned access errors when setting softlockup_thresh on 64 bit platforms. Allow softlockup detection to be disabled by setting softlockup_thresh <= 0. Detect that boot time softlockup detection has been disabled earlier in softlockup_tick. Signed-off-by: Dimitri Sivanich Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/softlockup.c | 12 ++++++++++-- kernel/sysctl.c | 9 +++++---- 2 files changed, 15 insertions(+), 6 deletions(-) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 78e0ad21cb0..a3a0b239b7f 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -25,7 +25,7 @@ static DEFINE_PER_CPU(unsigned long, print_timestamp); static DEFINE_PER_CPU(struct task_struct *, watchdog_task); static int __read_mostly did_panic; -unsigned long __read_mostly softlockup_thresh = 60; +int __read_mostly softlockup_thresh = 60; /* * Should we panic (and reboot, if panic_timeout= is set) when a @@ -94,6 +94,14 @@ void softlockup_tick(void) struct pt_regs *regs = get_irq_regs(); unsigned long now; + /* Is detection switched off? */ + if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) { + /* Be sure we don't false trigger if switched back on */ + if (touch_timestamp) + per_cpu(touch_timestamp, this_cpu) = 0; + return; + } + if (touch_timestamp == 0) { touch_softlockup_watchdog(); return; @@ -104,7 +112,7 @@ void softlockup_tick(void) /* report at most once a second */ if ((print_timestamp >= touch_timestamp && print_timestamp < (touch_timestamp + 1)) || - did_panic || !per_cpu(watchdog_task, this_cpu)) { + did_panic) { return; } diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 2d3b388c402..31c19a79738 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -84,12 +84,13 @@ extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; /* Constants used for minimum and maximum */ -#if defined(CONFIG_DETECT_SOFTLOCKUP) || defined(CONFIG_HIGHMEM) +#ifdef CONFIG_HIGHMEM static int one = 1; #endif #ifdef CONFIG_DETECT_SOFTLOCKUP static int sixty = 60; +static int neg_one = -1; #endif #ifdef CONFIG_MMU @@ -742,11 +743,11 @@ static struct ctl_table kern_table[] = { .ctl_name = CTL_UNNUMBERED, .procname = "softlockup_thresh", .data = &softlockup_thresh, - .maxlen = sizeof(unsigned long), + .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, - .extra1 = &one, + .extra1 = &neg_one, .extra2 = &sixty, }, { -- cgit v1.2.3 From 1c4cd6dd1d0fd3057bb6b8c87460049497889d1b Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 21:21:14 +0200 Subject: softlockup: fix softlockup_thresh fix Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 31c19a79738..a829dc8d7a9 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -84,7 +84,7 @@ extern int latencytop_enabled; extern int sysctl_nr_open_min, sysctl_nr_open_max; /* Constants used for minimum and maximum */ -#ifdef CONFIG_HIGHMEM +#if defined(CONFIG_HIGHMEM) || defined(CONFIG_DETECT_SOFTLOCKUP) static int one = 1; #endif -- cgit v1.2.3 From 02ff375590ac4140d88afc76505df1ad45c6af59 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Mon, 12 May 2008 15:43:53 +0200 Subject: softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds Fix (probably theoretical only) rq->clock update bug: in tick_nohz_update_jiffies() [which is called on all irq entry on all cpus where the irq entry hits an idle cpu] we call touch_softlockup_watchdog() before we update jiffies. That works fine most of the time when idle timeouts are within 60 seconds. But when an idle timeout is beyond 60 seconds, jiffies is updated with a jump of more than 60 seconds, which causes a jump in cpu-clock of more than 60 seconds, triggering a false positive. Reported-by: David Miller Signed-off-by: Ingo Molnar --- kernel/time/tick-sched.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index b854a895591..28abad66fc8 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -133,8 +133,6 @@ void tick_nohz_update_jiffies(void) if (!ts->tick_stopped) return; - touch_softlockup_watchdog(); - cpu_clear(cpu, nohz_cpu_mask); now = ktime_get(); ts->idle_waketime = now; @@ -142,6 +140,8 @@ void tick_nohz_update_jiffies(void) local_irq_save(flags); tick_do_update_jiffies64(now); local_irq_restore(flags); + + touch_softlockup_watchdog(); } void tick_nohz_stop_idle(int cpu) -- cgit v1.2.3 From 8c2238eaaf0f774ca0f8d9daad7a616429bbb7f1 Mon Sep 17 00:00:00 2001 From: Jason Wessel Date: Tue, 27 May 2008 12:23:29 -0500 Subject: softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression The touch_nmi_watchdog() routine on x86 ultimately calls touch_softlockup_watchdog(). The problem is that to touch the softlockup watchdog, the cpu_clock code has to be called which could involve multiple cpu locks and can lead to a hard hang if one of the locks is held by a processor that is not going to return anytime soon (such as could be the case with kgdb or perhaps even with some other kind of exception). This patch causes the public version of the touch_softlockup_watchdog() to defer the cpu clock access to a later point. The test case for this problem is to use the following kernel config options: CONFIG_KGDB_TESTS=y CONFIG_KGDB_TESTS_ON_BOOT=y CONFIG_KGDB_TESTS_BOOT_STRING="V1F100I100000" It should be noted that kgdb test suite and these options were not available until 2.6.26-rc2, so it was necessary to patch the kgdb test suite during the bisection. I would consider this patch a regression fix because the problem first appeared in commit 27ec4407790d075c325e1f4da0a19c56953cce23 when some logic was added to try to periodically sync the clocks. It was possible to work around this particular problem by simply not performing the sync anytime the system was in a critical context. This was ok until commit 3e51f33fcc7f55e6df25d15b55ed10c8b4da84cd, which added config option CONFIG_HAVE_UNSTABLE_SCHED_CLOCK and some multi-cpu locks to sync the clocks. It became clear that accessing this code from an nmi was the source of the lockups. Avoiding the access to the low level clock code from an code inside the NMI processing also fixed the problem with the 27ec44... commit. Signed-off-by: Jason Wessel Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index a3a0b239b7f..6b682d86bdd 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -64,12 +64,17 @@ static unsigned long get_timestamp(int this_cpu) return cpu_clock(this_cpu) >> 30LL; /* 2^30 ~= 10^9 */ } -void touch_softlockup_watchdog(void) +static void __touch_softlockup_watchdog(void) { int this_cpu = raw_smp_processor_id(); __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu); } + +void touch_softlockup_watchdog(void) +{ + __raw_get_cpu_var(touch_timestamp) = 0; +} EXPORT_SYMBOL(touch_softlockup_watchdog); void touch_all_softlockup_watchdogs(void) @@ -103,7 +108,7 @@ void softlockup_tick(void) } if (touch_timestamp == 0) { - touch_softlockup_watchdog(); + __touch_softlockup_watchdog(); return; } @@ -118,7 +123,7 @@ void softlockup_tick(void) /* do not print during early bootup: */ if (unlikely(system_state != SYSTEM_RUNNING)) { - touch_softlockup_watchdog(); + __touch_softlockup_watchdog(); return; } @@ -243,7 +248,7 @@ static int watchdog(void *__bind_cpu) sched_setscheduler(current, SCHED_FIFO, ¶m); /* initialize timestamp */ - touch_softlockup_watchdog(); + __touch_softlockup_watchdog(); set_current_state(TASK_INTERRUPTIBLE); /* @@ -252,7 +257,7 @@ static int watchdog(void *__bind_cpu) * debug-printout triggers in softlockup_tick(). */ while (!kthread_should_stop()) { - touch_softlockup_watchdog(); + __touch_softlockup_watchdog(); schedule(); if (kthread_should_stop()) -- cgit v1.2.3 From 688c91755dc3d3c03d8c67c1df13c02be258768e Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Mon, 16 Jun 2008 15:51:08 -0700 Subject: softlockup: print a module list on being stuck Most places in the kernel that go BUG: print a module list (which is very useful for doing statistics and finding patterns), however the softlockup detector does not do this yet. This patch adds the one line change to fix this gap. Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 6b682d86bdd..f2bf5decb10 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -143,6 +143,7 @@ void softlockup_tick(void) printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n", this_cpu, now - touch_timestamp, current->comm, task_pid_nr(current)); + print_modules(); if (regs) show_regs(regs); else -- cgit v1.2.3 From 8d5be7f4e8515af461cbc8f07687ccc81507d508 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Wed, 25 Jun 2008 08:50:10 +0200 Subject: softlockup: show irqtrace This patch adds some information about when interrupts were last enabled and disabled to the output of the softlockup detector. Signed-off-by: Vegard Nossum Cc: Peter Zijlstra Cc: Johannes Weiner Cc: Arjan van de Ven Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index f2bf5decb10..97977ecc317 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include @@ -144,6 +145,7 @@ void softlockup_tick(void) this_cpu, now - touch_timestamp, current->comm, task_pid_nr(current)); print_modules(); + print_irqtrace_events(current); if (regs) show_regs(regs); else -- cgit v1.2.3 From dd7a1e5615b1719c0fdffee1ea5a7820ac8141a6 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Fri, 27 Jun 2008 15:07:21 +0200 Subject: softlockup: fix watchdog task wakeup frequency Updating the timestamp more often is pointless as we print the warnings only if we exceed the threshold. And the check for hung tasks relies on the last timestamp, so it will keep working correctly, too. Signed-off-by: Johannes Weiner Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 97977ecc317..d53ab702a7d 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -130,8 +130,11 @@ void softlockup_tick(void) now = get_timestamp(this_cpu); - /* Wake up the high-prio watchdog task every second: */ - if (now > (touch_timestamp + 1)) + /* + * Wake up the high-prio watchdog task twice per + * threshold timespan. + */ + if (now > touch_timestamp + softlockup_thresh/2) wake_up_process(per_cpu(watchdog_task, this_cpu)); /* Warn about unreasonable delays: */ -- cgit v1.2.3 From 3e2f69fdd1b00166e7d589bce56b2d36a9e74374 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Tue, 1 Jul 2008 09:12:04 +0200 Subject: softlockup: fix watchdog task wakeup frequency The print_timestamp can never be bigger than the touch_timestamp, at maximum it can be equal. And if it is, the second check for touch_timestamp + 1 bigger print_timestamp is always true, too. The check for equality is sufficient as we proceed in one-second-steps and are at least one second away from the last print-out if we have another timestamp. Signed-off-by: Johannes Weiner Cc: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/softlockup.c b/kernel/softlockup.c index d53ab702a7d..7bd8d1aadd5 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -116,11 +116,8 @@ void softlockup_tick(void) print_timestamp = per_cpu(print_timestamp, this_cpu); /* report at most once a second */ - if ((print_timestamp >= touch_timestamp && - print_timestamp < (touch_timestamp + 1)) || - did_panic) { + if (print_timestamp == touch_timestamp || did_panic) return; - } /* do not print during early bootup: */ if (unlikely(system_state != SYSTEM_RUNNING)) { -- cgit v1.2.3 From 0775b3dbcb6d17b531b36df520ddab735647f3f7 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 8 Jul 2008 15:07:08 -0700 Subject: suspend, xen: enable PM_SLEEP for CONFIG_XEN Xen save/restore requires PM_SLEEP to be set without requiring SUSPEND or HIBERNATION. Signed-off-by: Jeremy Fitzhardinge Cc: Stephen Tweedie Cc: Eduardo Habkost Cc: Mark McLoughlin Signed-off-by: Ingo Molnar --- kernel/power/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index b45da40e8d2..1436c47cb39 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -82,7 +82,7 @@ config PM_SLEEP_SMP config PM_SLEEP bool - depends on SUSPEND || HIBERNATION + depends on SUSPEND || HIBERNATION || XEN default y config SUSPEND -- cgit v1.2.3 From 6717ef1aa750b54ddb9d8854b91707ee21f0ad23 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 9 Jul 2008 22:17:01 +0200 Subject: Revert "suspend, xen: enable PM_SLEEP for CONFIG_XEN" This reverts commit 6fbbec428c8e7bb617da2e8a589af2e97bcf3bc4. Rafael doesnt like it - it breaks various assumptions. Signed-off-by: Ingo Molnar --- kernel/power/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index 1436c47cb39..b45da40e8d2 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -82,7 +82,7 @@ config PM_SLEEP_SMP config PM_SLEEP bool - depends on SUSPEND || HIBERNATION || XEN + depends on SUSPEND || HIBERNATION default y config SUSPEND -- cgit v1.2.3 From 93a0886e2368eafb9df5e2021fb185195cee88b2 Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Tue, 15 Jul 2008 13:43:42 -0700 Subject: x86, xen, power: fix up config dependencies on PM Xen save/restore needs bits of code enabled by PM_SLEEP, and PM_SLEEP depends on PM. So make XEN_SAVE_RESTORE depend on PM and PM_SLEEP depend on XEN_SAVE_RESTORE. Signed-off-by: Jeremy Fitzhardinge Acked-by: Rafael J. Wysocki Signed-off-by: Ingo Molnar --- kernel/power/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig index b45da40e8d2..59dfdf1e1d2 100644 --- a/kernel/power/Kconfig +++ b/kernel/power/Kconfig @@ -82,7 +82,7 @@ config PM_SLEEP_SMP config PM_SLEEP bool - depends on SUSPEND || HIBERNATION + depends on SUSPEND || HIBERNATION || XEN_SAVE_RESTORE default y config SUSPEND -- cgit v1.2.3 From d88c16919793a9f5dc93e7956da5bb089c7600b4 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 18 Jul 2008 08:59:24 +0200 Subject: Revert parts of "ftrace: do not trace scheduler functions" the removal of -mno-spe in the !ftrace case was not intended. Signed-off-by: Ingo Molnar --- kernel/Makefile | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/Makefile b/kernel/Makefile index 985ddb7da4d..15ab63ffe64 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -11,6 +11,8 @@ obj-y = sched.o fork.o exec_domain.o panic.o printk.o profile.o \ hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \ notifier.o ksysfs.o pm_qos_params.o sched_clock.o +CFLAGS_REMOVE_sched.o = -mno-spe + ifdef CONFIG_FTRACE # Do not trace debug files and internal ftrace files CFLAGS_REMOVE_lockdep.o = -pg -- cgit v1.2.3 From 13b40c1e40f3261e83ee514a08b77dbecb93021b Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 1 Jul 2008 10:32:50 -0700 Subject: sched: reduce stack size in isolated_cpu_setup() * Remove 16k stack requirements in isolated_cpu_setup when NR_CPUS=4096. Signed-off-by: Mike Travis Cc: Andrew Morton Signed-off-by: Ingo Molnar --- kernel/sched.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 99e6d850eca..1ee18dbb451 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -6768,7 +6768,8 @@ static cpumask_t cpu_isolated_map = CPU_MASK_NONE; /* Setup the mask of cpus configured for isolated domains */ static int __init isolated_cpu_setup(char *str) { - int ints[NR_CPUS], i; + static int __initdata ints[NR_CPUS]; + int i; str = get_options(str, ARRAY_SIZE(ints), ints); cpus_clear(cpu_isolated_map); -- cgit v1.2.3 From 7ebefa8ceefed44cc321be70afc54a585a68ac0b Mon Sep 17 00:00:00 2001 From: Dmitry Adamushko Date: Tue, 1 Jul 2008 23:32:15 +0200 Subject: sched: rework of "prioritize non-migratable tasks over migratable ones" (1) handle in a generic way all cases when a newly woken-up task is not migratable (not just a corner case when "rt_se->nr_cpus_allowed == 1") (2) if current is to be preempted, then make sure "p" will be picked up by pick_next_task_rt(). i.e. move task's group at the head of its list as well. currently, it's not a case for the group-scheduling case as described here: http://www.ussg.iu.edu/hypermail/linux/kernel/0807.0/0134.html Signed-off-by: Dmitry Adamushko Cc: Steven Rostedt Cc: Gregory Haskins Signed-off-by: Ingo Molnar --- kernel/sched_rt.c | 68 ++++++++++++++++++++++++++++++++----------------------- 1 file changed, 40 insertions(+), 28 deletions(-) (limited to 'kernel') diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 47ceac9e855..d3d1cccb3d7 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -599,11 +599,7 @@ static void __enqueue_rt_entity(struct sched_rt_entity *rt_se) if (group_rq && (rt_rq_throttled(group_rq) || !group_rq->rt_nr_running)) return; - if (rt_se->nr_cpus_allowed == 1) - list_add(&rt_se->run_list, queue); - else - list_add_tail(&rt_se->run_list, queue); - + list_add_tail(&rt_se->run_list, queue); __set_bit(rt_se_prio(rt_se), array->bitmap); inc_rt_tasks(rt_se, rt_rq); @@ -688,32 +684,34 @@ static void dequeue_task_rt(struct rq *rq, struct task_struct *p, int sleep) * Put task to the end of the run list without the overhead of dequeue * followed by enqueue. */ -static -void requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se) +static void +requeue_rt_entity(struct rt_rq *rt_rq, struct sched_rt_entity *rt_se, int head) { - struct rt_prio_array *array = &rt_rq->active; - if (on_rt_rq(rt_se)) { - list_del_init(&rt_se->run_list); - list_add_tail(&rt_se->run_list, - array->queue + rt_se_prio(rt_se)); + struct rt_prio_array *array = &rt_rq->active; + struct list_head *queue = array->queue + rt_se_prio(rt_se); + + if (head) + list_move(&rt_se->run_list, queue); + else + list_move_tail(&rt_se->run_list, queue); } } -static void requeue_task_rt(struct rq *rq, struct task_struct *p) +static void requeue_task_rt(struct rq *rq, struct task_struct *p, int head) { struct sched_rt_entity *rt_se = &p->rt; struct rt_rq *rt_rq; for_each_sched_rt_entity(rt_se) { rt_rq = rt_rq_of_se(rt_se); - requeue_rt_entity(rt_rq, rt_se); + requeue_rt_entity(rt_rq, rt_se, head); } } static void yield_task_rt(struct rq *rq) { - requeue_task_rt(rq, rq->curr); + requeue_task_rt(rq, rq->curr, 0); } #ifdef CONFIG_SMP @@ -753,6 +751,30 @@ static int select_task_rq_rt(struct task_struct *p, int sync) */ return task_cpu(p); } + +static void check_preempt_equal_prio(struct rq *rq, struct task_struct *p) +{ + cpumask_t mask; + + if (rq->curr->rt.nr_cpus_allowed == 1) + return; + + if (p->rt.nr_cpus_allowed != 1 + && cpupri_find(&rq->rd->cpupri, p, &mask)) + return; + + if (!cpupri_find(&rq->rd->cpupri, rq->curr, &mask)) + return; + + /* + * There appears to be other cpus that can accept + * current and none to run 'p', so lets reschedule + * to try and push current away: + */ + requeue_task_rt(rq, p, 1); + resched_task(rq->curr); +} + #endif /* CONFIG_SMP */ /* @@ -778,18 +800,8 @@ static void check_preempt_curr_rt(struct rq *rq, struct task_struct *p) * to move current somewhere else, making room for our non-migratable * task. */ - if((p->prio == rq->curr->prio) - && p->rt.nr_cpus_allowed == 1 - && rq->curr->rt.nr_cpus_allowed != 1) { - cpumask_t mask; - - if (cpupri_find(&rq->rd->cpupri, rq->curr, &mask)) - /* - * There appears to be other cpus that can accept - * current, so lets reschedule to try and push it away - */ - resched_task(rq->curr); - } + if (p->prio == rq->curr->prio && !need_resched()) + check_preempt_equal_prio(rq, p); #endif } @@ -1415,7 +1427,7 @@ static void task_tick_rt(struct rq *rq, struct task_struct *p, int queued) * on the queue: */ if (p->rt.run_list.prev != p->rt.run_list.next) { - requeue_task_rt(rq, p); + requeue_task_rt(rq, p, 0); set_tsk_need_resched(p); } } -- cgit v1.2.3 From e761b7725234276a802322549cee5255305a0930 Mon Sep 17 00:00:00 2001 From: Max Krasnyansky Date: Tue, 15 Jul 2008 04:43:49 -0700 Subject: cpu hotplug, sched: Introduce cpu_active_map and redo sched domain managment (take 2) This is based on Linus' idea of creating cpu_active_map that prevents scheduler load balancer from migrating tasks to the cpu that is going down. It allows us to simplify domain management code and avoid unecessary domain rebuilds during cpu hotplug event handling. Please ignore the cpusets part for now. It needs some more work in order to avoid crazy lock nesting. Although I did simplfy and unify domain reinitialization logic. We now simply call partition_sched_domains() in all the cases. This means that we're using exact same code paths as in cpusets case and hence the test below cover cpusets too. Cpuset changes to make rebuild_sched_domains() callable from various contexts are in the separate patch (right next after this one). This not only boots but also easily handles while true; do make clean; make -j 8; done and while true; do on-off-cpu 1; done at the same time. (on-off-cpu 1 simple does echo 0/1 > /sys/.../cpu1/online thing). Suprisingly the box (dual-core Core2) is quite usable. In fact I'm typing this on right now in gnome-terminal and things are moving just fine. Also this is running with most of the debug features enabled (lockdep, mutex, etc) no BUG_ONs or lockdep complaints so far. I believe I addressed all of the Dmitry's comments for original Linus' version. I changed both fair and rt balancer to mask out non-active cpus. And replaced cpu_is_offline() with !cpu_active() in the main scheduler code where it made sense (to me). Signed-off-by: Max Krasnyanskiy Acked-by: Linus Torvalds Acked-by: Peter Zijlstra Acked-by: Gregory Haskins Cc: dmitry.adamushko@gmail.com Cc: pj@sgi.com Signed-off-by: Ingo Molnar --- kernel/cpu.c | 30 ++++++++++++--- kernel/cpuset.c | 2 +- kernel/sched.c | 108 ++++++++++++++++++++++------------------------------ kernel/sched_fair.c | 3 ++ kernel/sched_rt.c | 7 ++++ 5 files changed, 80 insertions(+), 70 deletions(-) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index cfb1d43ab80..a1ac7ea245d 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -64,6 +64,8 @@ void __init cpu_hotplug_init(void) cpu_hotplug.refcount = 0; } +cpumask_t cpu_active_map; + #ifdef CONFIG_HOTPLUG_CPU void get_online_cpus(void) @@ -291,11 +293,20 @@ int __ref cpu_down(unsigned int cpu) int err = 0; cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_down(cpu, 0); + goto out; + } + + cpu_clear(cpu, cpu_active_map); + + err = _cpu_down(cpu, 0); + + if (cpu_online(cpu)) + cpu_set(cpu, cpu_active_map); +out: cpu_maps_update_done(); return err; } @@ -355,11 +366,18 @@ int __cpuinit cpu_up(unsigned int cpu) } cpu_maps_update_begin(); - if (cpu_hotplug_disabled) + + if (cpu_hotplug_disabled) { err = -EBUSY; - else - err = _cpu_up(cpu, 0); + goto out; + } + err = _cpu_up(cpu, 0); + + if (cpu_online(cpu)) + cpu_set(cpu, cpu_active_map); + +out: cpu_maps_update_done(); return err; } diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 459d601947a..3c3ef02f65f 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -564,7 +564,7 @@ update_domain_attr(struct sched_domain_attr *dattr, struct cpuset *c) * partition_sched_domains(). */ -static void rebuild_sched_domains(void) +void rebuild_sched_domains(void) { struct kfifo *q; /* queue of cpusets to be scanned */ struct cpuset *cp; /* scans q */ diff --git a/kernel/sched.c b/kernel/sched.c index 1ee18dbb451..c237624a8a0 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2881,7 +2881,7 @@ static void sched_migrate_task(struct task_struct *p, int dest_cpu) rq = task_rq_lock(p, &flags); if (!cpu_isset(dest_cpu, p->cpus_allowed) - || unlikely(cpu_is_offline(dest_cpu))) + || unlikely(!cpu_active(dest_cpu))) goto out; /* force the process onto the specified CPU */ @@ -3849,7 +3849,7 @@ int select_nohz_load_balancer(int stop_tick) /* * If we are going offline and still the leader, give up! */ - if (cpu_is_offline(cpu) && + if (!cpu_active(cpu) && atomic_read(&nohz.load_balancer) == cpu) { if (atomic_cmpxchg(&nohz.load_balancer, cpu, -1) != cpu) BUG(); @@ -5876,7 +5876,7 @@ static int __migrate_task(struct task_struct *p, int src_cpu, int dest_cpu) struct rq *rq_dest, *rq_src; int ret = 0, on_rq; - if (unlikely(cpu_is_offline(dest_cpu))) + if (unlikely(!cpu_active(dest_cpu))) return ret; rq_src = cpu_rq(src_cpu); @@ -7553,18 +7553,6 @@ void __attribute__((weak)) arch_update_cpu_topology(void) { } -/* - * Free current domain masks. - * Called after all cpus are attached to NULL domain. - */ -static void free_sched_domains(void) -{ - ndoms_cur = 0; - if (doms_cur != &fallback_doms) - kfree(doms_cur); - doms_cur = &fallback_doms; -} - /* * Set up scheduler domains and groups. Callers must hold the hotplug lock. * For now this just excludes isolated cpus, but could be used to @@ -7643,7 +7631,7 @@ static int dattrs_equal(struct sched_domain_attr *cur, int idx_cur, * ownership of it and will kfree it when done with it. If the caller * failed the kmalloc call, then it can pass in doms_new == NULL, * and partition_sched_domains() will fallback to the single partition - * 'fallback_doms'. + * 'fallback_doms', it also forces the domains to be rebuilt. * * Call with hotplug lock held */ @@ -7657,12 +7645,8 @@ void partition_sched_domains(int ndoms_new, cpumask_t *doms_new, /* always unregister in case we don't destroy any domains */ unregister_sched_domain_sysctl(); - if (doms_new == NULL) { - ndoms_new = 1; - doms_new = &fallback_doms; - cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map); - dattr_new = NULL; - } + if (doms_new == NULL) + ndoms_new = 0; /* Destroy deleted domains */ for (i = 0; i < ndoms_cur; i++) { @@ -7677,6 +7661,14 @@ match1: ; } + if (doms_new == NULL) { + ndoms_cur = 0; + ndoms_new = 1; + doms_new = &fallback_doms; + cpus_andnot(doms_new[0], cpu_online_map, cpu_isolated_map); + dattr_new = NULL; + } + /* Build new domains */ for (i = 0; i < ndoms_new; i++) { for (j = 0; j < ndoms_cur; j++) { @@ -7707,17 +7699,10 @@ match2: #if defined(CONFIG_SCHED_MC) || defined(CONFIG_SCHED_SMT) int arch_reinit_sched_domains(void) { - int err; - get_online_cpus(); - mutex_lock(&sched_domains_mutex); - detach_destroy_domains(&cpu_online_map); - free_sched_domains(); - err = arch_init_sched_domains(&cpu_online_map); - mutex_unlock(&sched_domains_mutex); + rebuild_sched_domains(); put_online_cpus(); - - return err; + return 0; } static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) @@ -7783,14 +7768,30 @@ int sched_create_sysfs_power_savings_entries(struct sysdev_class *cls) } #endif /* CONFIG_SCHED_MC || CONFIG_SCHED_SMT */ +#ifndef CONFIG_CPUSETS /* - * Force a reinitialization of the sched domains hierarchy. The domains - * and groups cannot be updated in place without racing with the balancing - * code, so we temporarily attach all running cpus to the NULL domain - * which will prevent rebalancing while the sched domains are recalculated. + * Add online and remove offline CPUs from the scheduler domains. + * When cpusets are enabled they take over this function. */ static int update_sched_domains(struct notifier_block *nfb, unsigned long action, void *hcpu) +{ + switch (action) { + case CPU_ONLINE: + case CPU_ONLINE_FROZEN: + case CPU_DEAD: + case CPU_DEAD_FROZEN: + partition_sched_domains(0, NULL, NULL); + return NOTIFY_OK; + + default: + return NOTIFY_DONE; + } +} +#endif + +static int update_runtime(struct notifier_block *nfb, + unsigned long action, void *hcpu) { int cpu = (int)(long)hcpu; @@ -7798,44 +7799,18 @@ static int update_sched_domains(struct notifier_block *nfb, case CPU_DOWN_PREPARE: case CPU_DOWN_PREPARE_FROZEN: disable_runtime(cpu_rq(cpu)); - /* fall-through */ - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - detach_destroy_domains(&cpu_online_map); - free_sched_domains(); return NOTIFY_OK; - case CPU_DOWN_FAILED: case CPU_DOWN_FAILED_FROZEN: case CPU_ONLINE: case CPU_ONLINE_FROZEN: enable_runtime(cpu_rq(cpu)); - /* fall-through */ - case CPU_UP_CANCELED: - case CPU_UP_CANCELED_FROZEN: - case CPU_DEAD: - case CPU_DEAD_FROZEN: - /* - * Fall through and re-initialise the domains. - */ - break; + return NOTIFY_OK; + default: return NOTIFY_DONE; } - -#ifndef CONFIG_CPUSETS - /* - * Create default domain partitioning if cpusets are disabled. - * Otherwise we let cpusets rebuild the domains based on the - * current setup. - */ - - /* The hotplug lock is already held by cpu_up/cpu_down */ - arch_init_sched_domains(&cpu_online_map); -#endif - - return NOTIFY_OK; } void __init sched_init_smp(void) @@ -7855,8 +7830,15 @@ void __init sched_init_smp(void) cpu_set(smp_processor_id(), non_isolated_cpus); mutex_unlock(&sched_domains_mutex); put_online_cpus(); + +#ifndef CONFIG_CPUSETS /* XXX: Theoretical race here - CPU may be hotplugged now */ hotcpu_notifier(update_sched_domains, 0); +#endif + + /* RT runtime code needs to handle some hotplug events */ + hotcpu_notifier(update_runtime, 0); + init_hrtick(); /* Move init over to a non-isolated CPU */ diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f2aa987027d..d924c679dfa 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -1004,6 +1004,8 @@ static void yield_task_fair(struct rq *rq) * not idle and an idle cpu is available. The span of cpus to * search starts with cpus closest then further out as needed, * so we always favor a closer, idle cpu. + * Domains may include CPUs that are not usable for migration, + * hence we need to mask them out (cpu_active_map) * * Returns the CPU we should wake onto. */ @@ -1031,6 +1033,7 @@ static int wake_idle(int cpu, struct task_struct *p) || ((sd->flags & SD_WAKE_IDLE_FAR) && !task_hot(p, task_rq(p)->clock, sd))) { cpus_and(tmp, sd->span, p->cpus_allowed); + cpus_and(tmp, tmp, cpu_active_map); for_each_cpu_mask(i, tmp) { if (idle_cpu(i)) { if (i != task_cpu(p)) { diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index d3d1cccb3d7..50735bb9614 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -933,6 +933,13 @@ static int find_lowest_rq(struct task_struct *task) if (!cpupri_find(&task_rq(task)->rd->cpupri, task, lowest_mask)) return -1; /* No targets found */ + /* + * Only consider CPUs that are usable for migration. + * I guess we might want to change cpupri_find() to ignore those + * in the first place. + */ + cpus_and(*lowest_mask, *lowest_mask, cpu_active_map); + /* * At this point we have built a mask of cpus representing the * lowest priority tasks in the system. Now we want to elect -- cgit v1.2.3 From 39b0fad7121eace85770e7a4c6dc35dfd2879768 Mon Sep 17 00:00:00 2001 From: Max Krasnyansky Date: Tue, 15 Jul 2008 20:56:26 -0700 Subject: cpu hotplug: Make cpu_active_map synchronization dependency clear This goes on top of the cpu_active_map (take 2) patch. Currently we depend on the stop_machine to provide nescessesary synchronization for the cpu_active_map updates. As Dmitry Adamushko pointed this is fragile and is not much clearer than the previous scheme. In other words we do not want to depend on the internal stop machine operation here. So make the synchronization rules clear by doing synchronize_sched() after clearing out cpu active bit. Tested on quad-Core2 with: while true; do for i in 1 2 3; do echo 0 > /sys/devices/system/cpu/cpu$i/online done for i in 1 2 3; do echo 1 > /sys/devices/system/cpu/cpu$i/online done done and stress -c 200 No lockdep, preempt or other complaints. Signed-off-by: Max Krasnyansky Acked-by: Peter Zijlstra Signed-off-by: Ingo Molnar --- kernel/cpu.c | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'kernel') diff --git a/kernel/cpu.c b/kernel/cpu.c index a1ac7ea245d..033603c1d7c 100644 --- a/kernel/cpu.c +++ b/kernel/cpu.c @@ -301,6 +301,16 @@ int __ref cpu_down(unsigned int cpu) cpu_clear(cpu, cpu_active_map); + /* + * Make sure the all cpus did the reschedule and are not + * using stale version of the cpu_active_map. + * This is not strictly necessary becuase stop_machine() + * that we run down the line already provides the required + * synchronization. But it's really a side effect and we do not + * want to depend on the innards of the stop_machine here. + */ + synchronize_sched(); + err = _cpu_down(cpu, 0); if (cpu_online(cpu)) -- cgit v1.2.3 From 577b4a58d2e74a4d48050eeea3e3f952ce04eb86 Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 11 Jul 2008 13:34:54 +0100 Subject: sched: fix warning in inc_rt_tasks() to not declare variable 'rq' if it's not needed Fix inc_rt_tasks() to not declare variable 'rq' if it's not needed. It is declared if CONFIG_SMP or CONFIG_RT_GROUP_SCHED, but only used if CONFIG_SMP. This is a consequence of patch 1f11eb6a8bc92536d9e93ead48fa3ffbd1478571 plus patch 1100ac91b6af02d8639d518fad5b434b1bf44ed6. Signed-off-by: David Howells Signed-off-by: Ingo Molnar --- kernel/sched_rt.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel') diff --git a/kernel/sched_rt.c b/kernel/sched_rt.c index 47ceac9e855..147004c651c 100644 --- a/kernel/sched_rt.c +++ b/kernel/sched_rt.c @@ -505,7 +505,9 @@ void inc_rt_tasks(struct sched_rt_entity *rt_se, struct rt_rq *rt_rq) rt_rq->rt_nr_running++; #if defined CONFIG_SMP || defined CONFIG_RT_GROUP_SCHED if (rt_se_prio(rt_se) < rt_rq->highest_prio) { +#ifdef CONFIG_SMP struct rq *rq = rq_of_rt_rq(rt_rq); +#endif rt_rq->highest_prio = rt_se_prio(rt_se); #ifdef CONFIG_SMP -- cgit v1.2.3 From 4dca10a96041f78bed11ce9e4a5cfde813ec4ccb Mon Sep 17 00:00:00 2001 From: Hiroshi Shimamoto Date: Mon, 7 Jul 2008 18:37:04 -0700 Subject: softlockup: fix invalid proc_handler for softlockup_panic The type of softlockup_panic is int, but the proc_handler is proc_doulongvec_minmax(). This handler is for unsigned long. This handler should be proc_dointvec_minmax(). Signed-off-by: Hiroshi Shimamoto Signed-off-by: Ingo Molnar --- kernel/sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 3e56d2f9141..ab59ac008ca 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -741,7 +741,7 @@ static struct ctl_table kern_table[] = { .data = &softlockup_panic, .maxlen = sizeof(int), .mode = 0644, - .proc_handler = &proc_doulongvec_minmax, + .proc_handler = &proc_dointvec_minmax, .strategy = &sysctl_intvec, .extra1 = &zero, .extra2 = &one, -- cgit v1.2.3 From 65c011845316d3c1381f478ca0d8265c43b3b039 Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 15 Jul 2008 14:14:30 -0700 Subject: cpumask: Replace cpumask_of_cpu with cpumask_of_cpu_ptr * This patch replaces the dangerous lvalue version of cpumask_of_cpu with new cpumask_of_cpu_ptr macros. These are patterned after the node_to_cpumask_ptr macros. In general terms, if there is a cpumask_of_cpu_map[] then a pointer to the cpumask_of_cpu_map[cpu] entry is used. The cpumask_of_cpu_map is provided when there is a large NR_CPUS count, reducing greatly the amount of code generated and stack space used for cpumask_of_cpu(). The pointer to the cpumask_t value is needed for calling set_cpus_allowed_ptr() to reduce the amount of stack space needed to pass the cpumask_t value. If there isn't a cpumask_of_cpu_map[], then a temporary variable is declared and filled in with value from cpumask_of_cpu(cpu) as well as a pointer variable pointing to this temporary variable. Afterwards, the pointer is used to reference the cpumask value. The compiler will optimize out the extra dereference through the pointer as well as the stack space used for the pointer, resulting in identical code. A good example of the orthogonal usages is in net/sunrpc/svc.c: case SVC_POOL_PERCPU: { unsigned int cpu = m->pool_to[pidx]; cpumask_of_cpu_ptr(cpumask, cpu); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, cpumask); return 1; } case SVC_POOL_PERNODE: { unsigned int node = m->pool_to[pidx]; node_to_cpumask_ptr(nodecpumask, node); *oldmask = current->cpus_allowed; set_cpus_allowed_ptr(current, nodecpumask); return 1; } Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar --- kernel/stop_machine.c | 3 ++- kernel/trace/trace_sysprof.c | 4 +++- 2 files changed, 5 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/stop_machine.c b/kernel/stop_machine.c index ba9b2054ecb..738b411ff2d 100644 --- a/kernel/stop_machine.c +++ b/kernel/stop_machine.c @@ -33,8 +33,9 @@ static int stopmachine(void *cpu) { int irqs_disabled = 0; int prepared = 0; + cpumask_of_cpu_ptr(cpumask, (int)(long)cpu); - set_cpus_allowed_ptr(current, &cpumask_of_cpu((int)(long)cpu)); + set_cpus_allowed_ptr(current, cpumask); /* Ack: we are alive */ smp_mb(); /* Theoretically the ack = 0 might not be on this CPU yet. */ diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index 2301e1e7c60..63528086337 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -213,7 +213,9 @@ static void start_stack_timers(void) int cpu; for_each_online_cpu(cpu) { - set_cpus_allowed_ptr(current, &cpumask_of_cpu(cpu)); + cpumask_of_cpu_ptr(new_mask, cpu); + + set_cpus_allowed_ptr(current, new_mask); start_stack_timer(cpu); } set_cpus_allowed_ptr(current, &saved_mask); -- cgit v1.2.3 From c18a41fbbc500ac0307ffd2b0ae73c2af9d0b0ab Mon Sep 17 00:00:00 2001 From: Mike Travis Date: Tue, 15 Jul 2008 14:14:34 -0700 Subject: cpumask: Optimize cpumask_of_cpu in kernel/time/tick-common.c * Optimize various places where a pointer to the cpumask_of_cpu value will result in reducing stack pressure. Signed-off-by: Mike Travis Signed-off-by: Ingo Molnar --- kernel/time/tick-common.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 4f3886562b8..bf43284d685 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -135,7 +135,7 @@ void tick_setup_periodic(struct clock_event_device *dev, int broadcast) */ static void tick_setup_device(struct tick_device *td, struct clock_event_device *newdev, int cpu, - cpumask_t cpumask) + const cpumask_t *cpumask) { ktime_t next_event; void (*handler)(struct clock_event_device *) = NULL; @@ -169,8 +169,8 @@ static void tick_setup_device(struct tick_device *td, * When the device is not per cpu, pin the interrupt to the * current cpu: */ - if (!cpus_equal(newdev->cpumask, cpumask)) - irq_set_affinity(newdev->irq, cpumask); + if (!cpus_equal(newdev->cpumask, *cpumask)) + irq_set_affinity(newdev->irq, *cpumask); /* * When global broadcasting is active, check if the current @@ -196,20 +196,20 @@ static int tick_check_new_device(struct clock_event_device *newdev) struct tick_device *td; int cpu, ret = NOTIFY_OK; unsigned long flags; - cpumask_t cpumask; + cpumask_of_cpu_ptr_declare(cpumask); spin_lock_irqsave(&tick_device_lock, flags); cpu = smp_processor_id(); + cpumask_of_cpu_ptr_next(cpumask, cpu); if (!cpu_isset(cpu, newdev->cpumask)) goto out_bc; td = &per_cpu(tick_cpu_device, cpu); curdev = td->evtdev; - cpumask = cpumask_of_cpu(cpu); /* cpu local device ? */ - if (!cpus_equal(newdev->cpumask, cpumask)) { + if (!cpus_equal(newdev->cpumask, *cpumask)) { /* * If the cpu affinity of the device interrupt can not @@ -222,7 +222,7 @@ static int tick_check_new_device(struct clock_event_device *newdev) * If we have a cpu local device already, do not replace it * by a non cpu local device */ - if (curdev && cpus_equal(curdev->cpumask, cpumask)) + if (curdev && cpus_equal(curdev->cpumask, *cpumask)) goto out_bc; } -- cgit v1.2.3 From 31656519e132f6612584815f128c83976a9aaaef Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 18 Jul 2008 18:01:23 +0200 Subject: sched, x86: clean up hrtick implementation random uvesafb failures were reported against Gentoo: http://bugs.gentoo.org/show_bug.cgi?id=222799 and Mihai Moldovan bisected it back to: > 8f4d37ec073c17e2d4aa8851df5837d798606d6f is first bad commit > commit 8f4d37ec073c17e2d4aa8851df5837d798606d6f > Author: Peter Zijlstra > Date: Fri Jan 25 21:08:29 2008 +0100 > > sched: high-res preemption tick Linus suspected it to be hrtick + vm86 interaction and observed: > Btw, Peter, Ingo: I think that commit is doing bad things. They aren't > _incorrect_ per se, but they are definitely bad. > > Why? > > Using random _TIF_WORK_MASK flags is really impolite for doing > "scheduling" work. There's a reason that arch/x86/kernel/entry_32.S > special-cases the _TIF_NEED_RESCHED flag: we don't want to exit out of > vm86 mode unnecessarily. > > See the "work_notifysig_v86" label, and how it does that > "save_v86_state()" thing etc etc. Right, I never liked having to fiddle with those TIF flags. Initially I needed it because the hrtimer base lock could not nest in the rq lock. That however is fixed these days. Currently the only reason left to fiddle with the TIF flags is remote wakeups. We cannot program a remote cpu's hrtimer. I've been thinking about using the new and improved IPI function call stuff to implement hrtimer_start_on(). However that does require that smp_call_function_single(.wait=0) works from interrupt context - /me looks at the latest series from Jens - Yes that does seem to be supported, good. Here's a stab at cleaning this stuff up ... Mihai reported test success as well. Signed-off-by: Peter Zijlstra Tested-by: Mihai Moldovan Cc: Michal Januszewski Cc: Antonino Daplas Signed-off-by: Ingo Molnar --- kernel/Kconfig.hz | 2 +- kernel/sched.c | 202 ++++++++++++++++------------------------------------ kernel/sched_fair.c | 5 +- 3 files changed, 63 insertions(+), 146 deletions(-) (limited to 'kernel') diff --git a/kernel/Kconfig.hz b/kernel/Kconfig.hz index 526128a2e62..2a202a84675 100644 --- a/kernel/Kconfig.hz +++ b/kernel/Kconfig.hz @@ -55,4 +55,4 @@ config HZ default 1000 if HZ_1000 config SCHED_HRTICK - def_bool HIGH_RES_TIMERS && X86 + def_bool HIGH_RES_TIMERS diff --git a/kernel/sched.c b/kernel/sched.c index 1ee18dbb451..c13c75e9f9f 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -571,8 +571,10 @@ struct rq { #endif #ifdef CONFIG_SCHED_HRTICK - unsigned long hrtick_flags; - ktime_t hrtick_expire; +#ifdef CONFIG_SMP + int hrtick_csd_pending; + struct call_single_data hrtick_csd; +#endif struct hrtimer hrtick_timer; #endif @@ -983,13 +985,6 @@ static struct rq *this_rq_lock(void) return rq; } -static void __resched_task(struct task_struct *p, int tif_bit); - -static inline void resched_task(struct task_struct *p) -{ - __resched_task(p, TIF_NEED_RESCHED); -} - #ifdef CONFIG_SCHED_HRTICK /* * Use HR-timers to deliver accurate preemption points. @@ -1001,25 +996,6 @@ static inline void resched_task(struct task_struct *p) * When we get rescheduled we reprogram the hrtick_timer outside of the * rq->lock. */ -static inline void resched_hrt(struct task_struct *p) -{ - __resched_task(p, TIF_HRTICK_RESCHED); -} - -static inline void resched_rq(struct rq *rq) -{ - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - resched_task(rq->curr); - spin_unlock_irqrestore(&rq->lock, flags); -} - -enum { - HRTICK_SET, /* re-programm hrtick_timer */ - HRTICK_RESET, /* not a new slice */ - HRTICK_BLOCK, /* stop hrtick operations */ -}; /* * Use hrtick when: @@ -1030,72 +1006,17 @@ static inline int hrtick_enabled(struct rq *rq) { if (!sched_feat(HRTICK)) return 0; - if (unlikely(test_bit(HRTICK_BLOCK, &rq->hrtick_flags))) + if (!cpu_online(cpu_of(rq))) return 0; return hrtimer_is_hres_active(&rq->hrtick_timer); } -/* - * Called to set the hrtick timer state. - * - * called with rq->lock held and irqs disabled - */ -static void hrtick_start(struct rq *rq, u64 delay, int reset) -{ - assert_spin_locked(&rq->lock); - - /* - * preempt at: now + delay - */ - rq->hrtick_expire = - ktime_add_ns(rq->hrtick_timer.base->get_time(), delay); - /* - * indicate we need to program the timer - */ - __set_bit(HRTICK_SET, &rq->hrtick_flags); - if (reset) - __set_bit(HRTICK_RESET, &rq->hrtick_flags); - - /* - * New slices are called from the schedule path and don't need a - * forced reschedule. - */ - if (reset) - resched_hrt(rq->curr); -} - static void hrtick_clear(struct rq *rq) { if (hrtimer_active(&rq->hrtick_timer)) hrtimer_cancel(&rq->hrtick_timer); } -/* - * Update the timer from the possible pending state. - */ -static void hrtick_set(struct rq *rq) -{ - ktime_t time; - int set, reset; - unsigned long flags; - - WARN_ON_ONCE(cpu_of(rq) != smp_processor_id()); - - spin_lock_irqsave(&rq->lock, flags); - set = __test_and_clear_bit(HRTICK_SET, &rq->hrtick_flags); - reset = __test_and_clear_bit(HRTICK_RESET, &rq->hrtick_flags); - time = rq->hrtick_expire; - clear_thread_flag(TIF_HRTICK_RESCHED); - spin_unlock_irqrestore(&rq->lock, flags); - - if (set) { - hrtimer_start(&rq->hrtick_timer, time, HRTIMER_MODE_ABS); - if (reset && !hrtimer_active(&rq->hrtick_timer)) - resched_rq(rq); - } else - hrtick_clear(rq); -} - /* * High-resolution timer tick. * Runs from hardirq context with interrupts disabled. @@ -1115,27 +1036,37 @@ static enum hrtimer_restart hrtick(struct hrtimer *timer) } #ifdef CONFIG_SMP -static void hotplug_hrtick_disable(int cpu) +/* + * called from hardirq (IPI) context + */ +static void __hrtick_start(void *arg) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; - - spin_lock_irqsave(&rq->lock, flags); - rq->hrtick_flags = 0; - __set_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); + struct rq *rq = arg; - hrtick_clear(rq); + spin_lock(&rq->lock); + hrtimer_restart(&rq->hrtick_timer); + rq->hrtick_csd_pending = 0; + spin_unlock(&rq->lock); } -static void hotplug_hrtick_enable(int cpu) +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) { - struct rq *rq = cpu_rq(cpu); - unsigned long flags; + struct hrtimer *timer = &rq->hrtick_timer; + ktime_t time = ktime_add_ns(timer->base->get_time(), delay); - spin_lock_irqsave(&rq->lock, flags); - __clear_bit(HRTICK_BLOCK, &rq->hrtick_flags); - spin_unlock_irqrestore(&rq->lock, flags); + timer->expires = time; + + if (rq == this_rq()) { + hrtimer_restart(timer); + } else if (!rq->hrtick_csd_pending) { + __smp_call_function_single(cpu_of(rq), &rq->hrtick_csd); + rq->hrtick_csd_pending = 1; + } } static int @@ -1150,16 +1081,7 @@ hotplug_hrtick(struct notifier_block *nfb, unsigned long action, void *hcpu) case CPU_DOWN_PREPARE_FROZEN: case CPU_DEAD: case CPU_DEAD_FROZEN: - hotplug_hrtick_disable(cpu); - return NOTIFY_OK; - - case CPU_UP_PREPARE: - case CPU_UP_PREPARE_FROZEN: - case CPU_DOWN_FAILED: - case CPU_DOWN_FAILED_FROZEN: - case CPU_ONLINE: - case CPU_ONLINE_FROZEN: - hotplug_hrtick_enable(cpu); + hrtick_clear(cpu_rq(cpu)); return NOTIFY_OK; } @@ -1170,46 +1092,45 @@ static void init_hrtick(void) { hotcpu_notifier(hotplug_hrtick, 0); } -#endif /* CONFIG_SMP */ +#else +/* + * Called to set the hrtick timer state. + * + * called with rq->lock held and irqs disabled + */ +static void hrtick_start(struct rq *rq, u64 delay) +{ + hrtimer_start(&rq->hrtick_timer, ns_to_ktime(delay), HRTIMER_MODE_REL); +} -static void init_rq_hrtick(struct rq *rq) +static void init_hrtick(void) { - rq->hrtick_flags = 0; - hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - rq->hrtick_timer.function = hrtick; - rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; } +#endif /* CONFIG_SMP */ -void hrtick_resched(void) +static void init_rq_hrtick(struct rq *rq) { - struct rq *rq; - unsigned long flags; +#ifdef CONFIG_SMP + rq->hrtick_csd_pending = 0; - if (!test_thread_flag(TIF_HRTICK_RESCHED)) - return; + rq->hrtick_csd.flags = 0; + rq->hrtick_csd.func = __hrtick_start; + rq->hrtick_csd.info = rq; +#endif - local_irq_save(flags); - rq = cpu_rq(smp_processor_id()); - hrtick_set(rq); - local_irq_restore(flags); + hrtimer_init(&rq->hrtick_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + rq->hrtick_timer.function = hrtick; + rq->hrtick_timer.cb_mode = HRTIMER_CB_IRQSAFE_NO_SOFTIRQ; } #else static inline void hrtick_clear(struct rq *rq) { } -static inline void hrtick_set(struct rq *rq) -{ -} - static inline void init_rq_hrtick(struct rq *rq) { } -void hrtick_resched(void) -{ -} - static inline void init_hrtick(void) { } @@ -1228,16 +1149,16 @@ static inline void init_hrtick(void) #define tsk_is_polling(t) test_tsk_thread_flag(t, TIF_POLLING_NRFLAG) #endif -static void __resched_task(struct task_struct *p, int tif_bit) +static void resched_task(struct task_struct *p) { int cpu; assert_spin_locked(&task_rq(p)->lock); - if (unlikely(test_tsk_thread_flag(p, tif_bit))) + if (unlikely(test_tsk_thread_flag(p, TIF_NEED_RESCHED))) return; - set_tsk_thread_flag(p, tif_bit); + set_tsk_thread_flag(p, TIF_NEED_RESCHED); cpu = task_cpu(p); if (cpu == smp_processor_id()) @@ -1303,10 +1224,10 @@ void wake_up_idle_cpu(int cpu) #endif /* CONFIG_NO_HZ */ #else /* !CONFIG_SMP */ -static void __resched_task(struct task_struct *p, int tif_bit) +static void resched_task(struct task_struct *p) { assert_spin_locked(&task_rq(p)->lock); - set_tsk_thread_flag(p, tif_bit); + set_tsk_need_resched(p); } #endif /* CONFIG_SMP */ @@ -4395,7 +4316,7 @@ asmlinkage void __sched schedule(void) struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; - int cpu, hrtick = sched_feat(HRTICK); + int cpu; need_resched: preempt_disable(); @@ -4410,7 +4331,7 @@ need_resched_nonpreemptible: schedule_debug(prev); - if (hrtick) + if (sched_feat(HRTICK)) hrtick_clear(rq); /* @@ -4457,9 +4378,6 @@ need_resched_nonpreemptible: } else spin_unlock_irq(&rq->lock); - if (hrtick) - hrtick_set(rq); - if (unlikely(reacquire_kernel_lock(current) < 0)) goto need_resched_nonpreemptible; diff --git a/kernel/sched_fair.c b/kernel/sched_fair.c index f2aa987027d..6893b3ed65f 100644 --- a/kernel/sched_fair.c +++ b/kernel/sched_fair.c @@ -878,7 +878,6 @@ entity_tick(struct cfs_rq *cfs_rq, struct sched_entity *curr, int queued) #ifdef CONFIG_SCHED_HRTICK static void hrtick_start_fair(struct rq *rq, struct task_struct *p) { - int requeue = rq->curr == p; struct sched_entity *se = &p->se; struct cfs_rq *cfs_rq = cfs_rq_of(se); @@ -899,10 +898,10 @@ static void hrtick_start_fair(struct rq *rq, struct task_struct *p) * Don't schedule slices shorter than 10000ns, that just * doesn't make sense. Rely on vruntime for fairness. */ - if (!requeue) + if (rq->curr != p) delta = max(10000LL, delta); - hrtick_start(rq, delta, requeue); + hrtick_start(rq, delta); } } #else /* !CONFIG_SCHED_HRTICK */ -- cgit v1.2.3 From ba42059fbd0aa1ac91b582412b5fedb1258f241f Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 20 Jul 2008 11:02:06 +0200 Subject: sched: hrtick_enabled() should use cpu_active() Peter pointed out that hrtick_enabled() should use cpu_active(). Signed-off-by: Ingo Molnar --- kernel/sched.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/sched.c b/kernel/sched.c index 85cf246cfdf..62b1b8ecb5c 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -1006,7 +1006,7 @@ static inline int hrtick_enabled(struct rq *rq) { if (!sched_feat(HRTICK)) return 0; - if (!cpu_online(cpu_of(rq))) + if (!cpu_active(cpu_of(rq))) return 0; return hrtimer_is_hres_active(&rq->hrtick_timer); } -- cgit v1.2.3 From 4a0b2b4dbe1335b8b9886ba3dc85a145d5d938ed Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 1 Jul 2008 18:48:41 +0200 Subject: sysdev: Pass the attribute to the low level sysdev show/store function This allow to dynamically generate attributes and share show/store functions between attributes. Right now most attributes are generated by special macros and lots of duplicated code. With the attribute passed it's instead possible to attach some data to the attribute and then use that in shared low level functions to do different things. I need this for the dynamically generated bank attributes in the x86 machine check code, but it'll allow some further cleanups. I converted all users in tree to the new show/store prototype. It's a single huge patch to avoid unbisectable sections. Runtime tested: x86-32, x86-64 Compiled only: ia64, powerpc Not compile tested/only grep converted: sh, arm, avr32 Signed-off-by: Andi Kleen Signed-off-by: Greg Kroah-Hartman --- kernel/rtmutex-tester.c | 7 ++++--- kernel/sched.c | 8 ++++++-- kernel/time/clocksource.c | 8 ++++++-- 3 files changed, 16 insertions(+), 7 deletions(-) (limited to 'kernel') diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c index 092e4c620af..a56f629b057 100644 --- a/kernel/rtmutex-tester.c +++ b/kernel/rtmutex-tester.c @@ -297,8 +297,8 @@ static int test_func(void *data) * * opcode:data */ -static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, - size_t count) +static ssize_t sysfs_test_command(struct sys_device *dev, struct sysdev_attribute *attr, + const char *buf, size_t count) { struct sched_param schedpar; struct test_thread_data *td; @@ -360,7 +360,8 @@ static ssize_t sysfs_test_command(struct sys_device *dev, const char *buf, * @dev: thread to query * @buf: char buffer to be filled with thread status info */ -static ssize_t sysfs_test_status(struct sys_device *dev, char *buf) +static ssize_t sysfs_test_status(struct sys_device *dev, struct sysdev_attribute *attr, + char *buf) { struct test_thread_data *td; struct task_struct *tsk; diff --git a/kernel/sched.c b/kernel/sched.c index 99e6d850eca..b1104ea5d25 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -7737,11 +7737,13 @@ static ssize_t sched_power_savings_store(const char *buf, size_t count, int smt) } #ifdef CONFIG_SCHED_MC -static ssize_t sched_mc_power_savings_show(struct sys_device *dev, char *page) +static ssize_t sched_mc_power_savings_show(struct sys_device *dev, + struct sysdev_attribute *attr, char *page) { return sprintf(page, "%u\n", sched_mc_power_savings); } static ssize_t sched_mc_power_savings_store(struct sys_device *dev, + struct sysdev_attribute *attr, const char *buf, size_t count) { return sched_power_savings_store(buf, count, 0); @@ -7751,11 +7753,13 @@ static SYSDEV_ATTR(sched_mc_power_savings, 0644, sched_mc_power_savings_show, #endif #ifdef CONFIG_SCHED_SMT -static ssize_t sched_smt_power_savings_show(struct sys_device *dev, char *page) +static ssize_t sched_smt_power_savings_show(struct sys_device *dev, + struct sysdev_attribute *attr, char *page) { return sprintf(page, "%u\n", sched_smt_power_savings); } static ssize_t sched_smt_power_savings_store(struct sys_device *dev, + struct sysdev_attribute *attr, const char *buf, size_t count) { return sched_power_savings_store(buf, count, 1); diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index dadde5361f3..b1c2da81b05 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -376,7 +376,8 @@ void clocksource_unregister(struct clocksource *cs) * Provides sysfs interface for listing current clocksource. */ static ssize_t -sysfs_show_current_clocksources(struct sys_device *dev, char *buf) +sysfs_show_current_clocksources(struct sys_device *dev, + struct sysdev_attribute *attr, char *buf) { ssize_t count = 0; @@ -397,6 +398,7 @@ sysfs_show_current_clocksources(struct sys_device *dev, char *buf) * clocksource selction. */ static ssize_t sysfs_override_clocksource(struct sys_device *dev, + struct sysdev_attribute *attr, const char *buf, size_t count) { struct clocksource *ovr = NULL; @@ -449,7 +451,9 @@ static ssize_t sysfs_override_clocksource(struct sys_device *dev, * Provides sysfs interface for listing registered clocksources */ static ssize_t -sysfs_show_available_clocksources(struct sys_device *dev, char *buf) +sysfs_show_available_clocksources(struct sys_device *dev, + struct sysdev_attribute *attr, + char *buf) { struct clocksource *src; ssize_t count = 0; -- cgit v1.2.3 From da39ba5e1d65e997a98f6eb93ba6e6eb505f6e3c Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:25 -0500 Subject: module: don't use stop_machine for waiting rmmod rmmod has a little-used "-w" option, meaning that instead of failing if the module is in use, it should block until the module becomes unused. In this case, we don't need to use stop_machine: Max Krasnyansky indicated that would be useful for SystemTap which loads/unloads new modules frequently. Cc: Max Krasnyansky Signed-off-by: Rusty Russell --- kernel/module.c | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 5f80478b746..705e1d5d516 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -639,8 +639,8 @@ static int __try_stop_module(void *_sref) { struct stopref *sref = _sref; - /* If it's not unused, quit unless we are told to block. */ - if ((sref->flags & O_NONBLOCK) && module_refcount(sref->mod) != 0) { + /* If it's not unused, quit unless we're forcing. */ + if (module_refcount(sref->mod) != 0) { if (!(*sref->forced = try_force_unload(sref->flags))) return -EWOULDBLOCK; } @@ -652,9 +652,16 @@ static int __try_stop_module(void *_sref) static int try_stop_module(struct module *mod, int flags, int *forced) { - struct stopref sref = { mod, flags, forced }; + if (flags & O_NONBLOCK) { + struct stopref sref = { mod, flags, forced }; - return stop_machine_run(__try_stop_module, &sref, NR_CPUS); + return stop_machine_run(__try_stop_module, &sref, NR_CPUS); + } else { + /* We don't need to stop the machine for this. */ + mod->state = MODULE_STATE_GOING; + synchronize_sched(); + return 0; + } } unsigned int module_refcount(struct module *mod) -- cgit v1.2.3 From dafd0940c96fec67974a88ed8e6b8ba3160394cd Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:25 -0500 Subject: module: generic each_symbol iterator function Introduce an each_symbol() iterator to avoid duplicating the knowledge about the 5 different sections containing symbols. Currently only used by find_symbol(), but will be used by symbol_put_addr() too. (Includes NULL ptr deref fix by Jiri Kosina ) Signed-off-by: Rusty Russell Cc: Jiri Kosina --- kernel/module.c | 244 +++++++++++++++++++++++++++++++------------------------- 1 file changed, 134 insertions(+), 110 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 705e1d5d516..c51c089c666 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -152,156 +152,180 @@ extern const unsigned long __start___kcrctab_unused_gpl[]; #define symversion(base, idx) ((base != NULL) ? ((base) + (idx)) : NULL) #endif -/* lookup symbol in given range of kernel_symbols */ -static const struct kernel_symbol *lookup_symbol(const char *name, - const struct kernel_symbol *start, - const struct kernel_symbol *stop) -{ - const struct kernel_symbol *ks = start; - for (; ks < stop; ks++) - if (strcmp(ks->name, name) == 0) - return ks; - return NULL; -} - -static bool always_ok(bool gplok, bool warn, const char *name) -{ - return true; -} - -static bool printk_unused_warning(bool gplok, bool warn, const char *name) -{ - if (warn) { - printk(KERN_WARNING "Symbol %s is marked as UNUSED, " - "however this module is using it.\n", name); - printk(KERN_WARNING - "This symbol will go away in the future.\n"); - printk(KERN_WARNING - "Please evalute if this is the right api to use and if " - "it really is, submit a report the linux kernel " - "mailinglist together with submitting your code for " - "inclusion.\n"); - } - return true; -} - -static bool gpl_only_unused_warning(bool gplok, bool warn, const char *name) -{ - if (!gplok) - return false; - return printk_unused_warning(gplok, warn, name); -} - -static bool gpl_only(bool gplok, bool warn, const char *name) -{ - return gplok; -} - -static bool warn_if_not_gpl(bool gplok, bool warn, const char *name) -{ - if (!gplok && warn) { - printk(KERN_WARNING "Symbol %s is being used " - "by a non-GPL module, which will not " - "be allowed in the future\n", name); - printk(KERN_WARNING "Please see the file " - "Documentation/feature-removal-schedule.txt " - "in the kernel source tree for more details.\n"); - } - return true; -} - struct symsearch { const struct kernel_symbol *start, *stop; const unsigned long *crcs; - bool (*check)(bool gplok, bool warn, const char *name); + enum { + NOT_GPL_ONLY, + GPL_ONLY, + WILL_BE_GPL_ONLY, + } licence; + bool unused; }; -/* Look through this array of symbol tables for a symbol match which - * passes the check function. */ -static const struct kernel_symbol *search_symarrays(const struct symsearch *arr, - unsigned int num, - const char *name, - bool gplok, - bool warn, - const unsigned long **crc) +static bool each_symbol_in_section(const struct symsearch *arr, + unsigned int arrsize, + struct module *owner, + bool (*fn)(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data), + void *data) { - unsigned int i; - const struct kernel_symbol *ks; - - for (i = 0; i < num; i++) { - ks = lookup_symbol(name, arr[i].start, arr[i].stop); - if (!ks || !arr[i].check(gplok, warn, name)) - continue; + unsigned int i, j; - if (crc) - *crc = symversion(arr[i].crcs, ks - arr[i].start); - return ks; + for (j = 0; j < arrsize; j++) { + for (i = 0; i < arr[j].stop - arr[j].start; i++) + if (fn(&arr[j], owner, i, data)) + return true; } - return NULL; + + return false; } -/* Find a symbol, return value, (optional) crc and (optional) module - * which owns it */ -static unsigned long find_symbol(const char *name, - struct module **owner, - const unsigned long **crc, - bool gplok, - bool warn) +/* Returns true as soon as fn returns true, otherwise false. */ +static bool each_symbol(bool (*fn)(const struct symsearch *arr, + struct module *owner, + unsigned int symnum, void *data), + void *data) { struct module *mod; - const struct kernel_symbol *ks; const struct symsearch arr[] = { { __start___ksymtab, __stop___ksymtab, __start___kcrctab, - always_ok }, + NOT_GPL_ONLY, false }, { __start___ksymtab_gpl, __stop___ksymtab_gpl, - __start___kcrctab_gpl, gpl_only }, + __start___kcrctab_gpl, + GPL_ONLY, false }, { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, - __start___kcrctab_gpl_future, warn_if_not_gpl }, + __start___kcrctab_gpl_future, + WILL_BE_GPL_ONLY, false }, { __start___ksymtab_unused, __stop___ksymtab_unused, - __start___kcrctab_unused, printk_unused_warning }, + __start___kcrctab_unused, + NOT_GPL_ONLY, true }, { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, - __start___kcrctab_unused_gpl, gpl_only_unused_warning }, + __start___kcrctab_unused_gpl, + GPL_ONLY, true }, }; - /* Core kernel first. */ - ks = search_symarrays(arr, ARRAY_SIZE(arr), name, gplok, warn, crc); - if (ks) { - if (owner) - *owner = NULL; - return ks->value; - } + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) + return true; - /* Now try modules. */ list_for_each_entry(mod, &modules, list) { struct symsearch arr[] = { { mod->syms, mod->syms + mod->num_syms, mod->crcs, - always_ok }, + NOT_GPL_ONLY, false }, { mod->gpl_syms, mod->gpl_syms + mod->num_gpl_syms, - mod->gpl_crcs, gpl_only }, + mod->gpl_crcs, + GPL_ONLY, false }, { mod->gpl_future_syms, mod->gpl_future_syms + mod->num_gpl_future_syms, - mod->gpl_future_crcs, warn_if_not_gpl }, + mod->gpl_future_crcs, + WILL_BE_GPL_ONLY, false }, { mod->unused_syms, mod->unused_syms + mod->num_unused_syms, - mod->unused_crcs, printk_unused_warning }, + mod->unused_crcs, + NOT_GPL_ONLY, true }, { mod->unused_gpl_syms, mod->unused_gpl_syms + mod->num_unused_gpl_syms, - mod->unused_gpl_crcs, gpl_only_unused_warning }, + mod->unused_gpl_crcs, + GPL_ONLY, true }, }; - ks = search_symarrays(arr, ARRAY_SIZE(arr), - name, gplok, warn, crc); - if (ks) { - if (owner) - *owner = mod; - return ks->value; + if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) + return true; + } + return false; +} + +struct find_symbol_arg { + /* Input */ + const char *name; + bool gplok; + bool warn; + + /* Output */ + struct module *owner; + const unsigned long *crc; + unsigned long value; +}; + +static bool find_symbol_in_section(const struct symsearch *syms, + struct module *owner, + unsigned int symnum, void *data) +{ + struct find_symbol_arg *fsa = data; + + if (strcmp(syms->start[symnum].name, fsa->name) != 0) + return false; + + if (!fsa->gplok) { + if (syms->licence == GPL_ONLY) + return false; + if (syms->licence == WILL_BE_GPL_ONLY && fsa->warn) { + printk(KERN_WARNING "Symbol %s is being used " + "by a non-GPL module, which will not " + "be allowed in the future\n", fsa->name); + printk(KERN_WARNING "Please see the file " + "Documentation/feature-removal-schedule.txt " + "in the kernel source tree for more details.\n"); } } + if (syms->unused && fsa->warn) { + printk(KERN_WARNING "Symbol %s is marked as UNUSED, " + "however this module is using it.\n", fsa->name); + printk(KERN_WARNING + "This symbol will go away in the future.\n"); + printk(KERN_WARNING + "Please evalute if this is the right api to use and if " + "it really is, submit a report the linux kernel " + "mailinglist together with submitting your code for " + "inclusion.\n"); + } + + fsa->owner = owner; + fsa->crc = symversion(syms->crcs, symnum); + fsa->value = syms->start[symnum].value; + return true; +} + +/* Find a symbol, return value, (optional) crc and (optional) module + * which owns it */ +static unsigned long find_symbol(const char *name, + struct module **owner, + const unsigned long **crc, + bool gplok, + bool warn) +{ + struct find_symbol_arg fsa; + + fsa.name = name; + fsa.gplok = gplok; + fsa.warn = warn; + + if (each_symbol(find_symbol_in_section, &fsa)) { + if (owner) + *owner = fsa.owner; + if (crc) + *crc = fsa.crc; + return fsa.value; + } + DEBUGP("Failed to find symbol %s\n", name); return -ENOENT; } +/* lookup symbol in given range of kernel_symbols */ +static const struct kernel_symbol *lookup_symbol(const char *name, + const struct kernel_symbol *start, + const struct kernel_symbol *stop) +{ + const struct kernel_symbol *ks = start; + for (; ks < stop; ks++) + if (strcmp(ks->name, name) == 0) + return ks; + return NULL; +} + /* Search for module by name: must hold module_mutex. */ static struct module *find_module(const char *name) { -- cgit v1.2.3 From f7f5b67557eac1131ba6532522e3c50eced34238 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 22 Jul 2008 19:24:26 -0500 Subject: Shrink struct module: CONFIG_UNUSED_SYMBOLS ifdefs module.c and module.h conatains code for finding exported symbols which are declared with EXPORT_UNUSED_SYMBOL, and this code is compiled in even if CONFIG_UNUSED_SYMBOLS is not set and thus there can be no EXPORT_UNUSED_SYMBOLs in modules anyway (because EXPORT_UNUSED_SYMBOL(x) are compiled out to nothing then). This patch adds required #ifdefs. Signed-off-by: Denys Vlasenko Signed-off-by: Rusty Russell --- kernel/module.c | 49 ++++++++++++++++++++++++++++++++++--------------- 1 file changed, 34 insertions(+), 15 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index c51c089c666..ea9580521eb 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -134,17 +134,19 @@ extern const struct kernel_symbol __start___ksymtab_gpl[]; extern const struct kernel_symbol __stop___ksymtab_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; -extern const struct kernel_symbol __start___ksymtab_unused[]; -extern const struct kernel_symbol __stop___ksymtab_unused[]; -extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; -extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const struct kernel_symbol __start___ksymtab_gpl_future[]; extern const struct kernel_symbol __stop___ksymtab_gpl_future[]; extern const unsigned long __start___kcrctab[]; extern const unsigned long __start___kcrctab_gpl[]; extern const unsigned long __start___kcrctab_gpl_future[]; +#ifdef CONFIG_UNUSED_SYMBOLS +extern const struct kernel_symbol __start___ksymtab_unused[]; +extern const struct kernel_symbol __stop___ksymtab_unused[]; +extern const struct kernel_symbol __start___ksymtab_unused_gpl[]; +extern const struct kernel_symbol __stop___ksymtab_unused_gpl[]; extern const unsigned long __start___kcrctab_unused[]; extern const unsigned long __start___kcrctab_unused_gpl[]; +#endif #ifndef CONFIG_MODVERSIONS #define symversion(base, idx) NULL @@ -198,12 +200,14 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, { __start___ksymtab_gpl_future, __stop___ksymtab_gpl_future, __start___kcrctab_gpl_future, WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { __start___ksymtab_unused, __stop___ksymtab_unused, __start___kcrctab_unused, NOT_GPL_ONLY, true }, { __start___ksymtab_unused_gpl, __stop___ksymtab_unused_gpl, __start___kcrctab_unused_gpl, GPL_ONLY, true }, +#endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), NULL, fn, data)) @@ -220,6 +224,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, mod->gpl_future_syms + mod->num_gpl_future_syms, mod->gpl_future_crcs, WILL_BE_GPL_ONLY, false }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->unused_syms + mod->num_unused_syms, mod->unused_crcs, @@ -228,6 +233,7 @@ static bool each_symbol(bool (*fn)(const struct symsearch *arr, mod->unused_gpl_syms + mod->num_unused_gpl_syms, mod->unused_gpl_crcs, GPL_ONLY, true }, +#endif }; if (each_symbol_in_section(arr, ARRAY_SIZE(arr), mod, fn, data)) @@ -270,6 +276,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, } } +#ifdef CONFIG_UNUSED_SYMBOLS if (syms->unused && fsa->warn) { printk(KERN_WARNING "Symbol %s is marked as UNUSED, " "however this module is using it.\n", fsa->name); @@ -281,6 +288,7 @@ static bool find_symbol_in_section(const struct symsearch *syms, "mailinglist together with submitting your code for " "inclusion.\n"); } +#endif fsa->owner = owner; fsa->crc = symversion(syms->crcs, symnum); @@ -1476,8 +1484,10 @@ static int verify_export_symbols(struct module *mod) { mod->syms, mod->num_syms }, { mod->gpl_syms, mod->num_gpl_syms }, { mod->gpl_future_syms, mod->num_gpl_future_syms }, +#ifdef CONFIG_UNUSED_SYMBOLS { mod->unused_syms, mod->num_unused_syms }, { mod->unused_gpl_syms, mod->num_unused_gpl_syms }, +#endif }; for (i = 0; i < ARRAY_SIZE(arr); i++) { @@ -1795,10 +1805,12 @@ static struct module *load_module(void __user *umod, unsigned int gplfutureindex; unsigned int gplfuturecrcindex; unsigned int unwindex = 0; +#ifdef CONFIG_UNUSED_SYMBOLS unsigned int unusedindex; unsigned int unusedcrcindex; unsigned int unusedgplindex; unsigned int unusedgplcrcindex; +#endif unsigned int markersindex; unsigned int markersstringsindex; struct module *mod; @@ -1881,13 +1893,15 @@ static struct module *load_module(void __user *umod, exportindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab"); gplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl"); gplfutureindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_gpl_future"); - unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); - unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); crcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab"); gplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl"); gplfuturecrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_gpl_future"); +#ifdef CONFIG_UNUSED_SYMBOLS + unusedindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused"); + unusedgplindex = find_sec(hdr, sechdrs, secstrings, "__ksymtab_unused_gpl"); unusedcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused"); unusedgplcrcindex = find_sec(hdr, sechdrs, secstrings, "__kcrctab_unused_gpl"); +#endif setupindex = find_sec(hdr, sechdrs, secstrings, "__param"); exindex = find_sec(hdr, sechdrs, secstrings, "__ex_table"); obsparmindex = find_sec(hdr, sechdrs, secstrings, "__obsparm"); @@ -2049,14 +2063,15 @@ static struct module *load_module(void __user *umod, mod->gpl_crcs = (void *)sechdrs[gplcrcindex].sh_addr; mod->num_gpl_future_syms = sechdrs[gplfutureindex].sh_size / sizeof(*mod->gpl_future_syms); - mod->num_unused_syms = sechdrs[unusedindex].sh_size / - sizeof(*mod->unused_syms); - mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / - sizeof(*mod->unused_gpl_syms); mod->gpl_future_syms = (void *)sechdrs[gplfutureindex].sh_addr; if (gplfuturecrcindex) mod->gpl_future_crcs = (void *)sechdrs[gplfuturecrcindex].sh_addr; +#ifdef CONFIG_UNUSED_SYMBOLS + mod->num_unused_syms = sechdrs[unusedindex].sh_size / + sizeof(*mod->unused_syms); + mod->num_unused_gpl_syms = sechdrs[unusedgplindex].sh_size / + sizeof(*mod->unused_gpl_syms); mod->unused_syms = (void *)sechdrs[unusedindex].sh_addr; if (unusedcrcindex) mod->unused_crcs = (void *)sechdrs[unusedcrcindex].sh_addr; @@ -2064,13 +2079,17 @@ static struct module *load_module(void __user *umod, if (unusedgplcrcindex) mod->unused_gpl_crcs = (void *)sechdrs[unusedgplcrcindex].sh_addr; +#endif #ifdef CONFIG_MODVERSIONS - if ((mod->num_syms && !crcindex) || - (mod->num_gpl_syms && !gplcrcindex) || - (mod->num_gpl_future_syms && !gplfuturecrcindex) || - (mod->num_unused_syms && !unusedcrcindex) || - (mod->num_unused_gpl_syms && !unusedgplcrcindex)) { + if ((mod->num_syms && !crcindex) + || (mod->num_gpl_syms && !gplcrcindex) + || (mod->num_gpl_future_syms && !gplfuturecrcindex) +#ifdef CONFIG_UNUSED_SYMBOLS + || (mod->num_unused_syms && !unusedcrcindex) + || (mod->num_unused_gpl_syms && !unusedgplcrcindex) +#endif + ) { printk(KERN_WARNING "%s: No versions for exported symbols.\n", mod->name); err = try_to_force_load(mod, "nocrc"); if (err) -- cgit v1.2.3 From 2f0f2a334bc38b61a9afca951185cd3844ee709d Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Tue, 22 Jul 2008 19:24:27 -0500 Subject: module: turn longs into ints for module sizes This shrinks module.o and each *.ko file. And finally, structure members which hold length of module code (four such members there) and count of symbols are converted from longs to ints. We cannot possibly have a module where 32 bits won't be enough to hold such counts. For one, module loading checks module size for sanity before loading, so such insanely big module will fail that test first. Signed-off-by: Denys Vlasenko Signed-off-by: Rusty Russell --- kernel/module.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index ea9580521eb..5c7eb0695b3 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -1567,7 +1567,7 @@ static int simplify_symbols(Elf_Shdr *sechdrs, } /* Update size with this section: return offset. */ -static long get_offset(unsigned long *size, Elf_Shdr *sechdr) +static long get_offset(unsigned int *size, Elf_Shdr *sechdr) { long ret; @@ -2562,7 +2562,7 @@ static int m_show(struct seq_file *m, void *p) struct module *mod = list_entry(p, struct module, list); char buf[8]; - seq_printf(m, "%s %lu", + seq_printf(m, "%s %u", mod->name, mod->init_size + mod->core_size); print_unload_info(m, mod); -- cgit v1.2.3 From 3a642e99babe0617febb6f402e1e063479f489db Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Tue, 22 Jul 2008 19:24:28 -0500 Subject: modules: Take a shortcut for checking if an address is in a module This patch keeps track of the boundaries of module allocation, in order to speed up module_text_address(). Inspired by Arjan's version, which required arch-specific defines: Various pieces of the kernel (lockdep, latencytop, etc) tend to store backtraces, sometimes at a relatively high frequency. In itself this isn't a big performance deal (after all you're using diagnostics features), but there have been some complaints from people who have over 100 modules loaded that this is a tad too slow. This is due to the new backtracer code which looks at every slot on the stack to see if it's a kernel/module text address, so that's 1024 slots. 1024 times 100 modules... that's a lot of list walking. Signed-off-by: Rusty Russell --- kernel/module.c | 24 ++++++++++++++++++++++-- 1 file changed, 22 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/module.c b/kernel/module.c index 5c7eb0695b3..d8b5605132a 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -70,6 +70,9 @@ static DECLARE_WAIT_QUEUE_HEAD(module_wq); static BLOCKING_NOTIFIER_HEAD(module_notify_list); +/* Bounds of module allocation, for speeding __module_text_address */ +static unsigned long module_addr_min = -1UL, module_addr_max = 0; + int register_module_notifier(struct notifier_block * nb) { return blocking_notifier_chain_register(&module_notify_list, nb); @@ -1779,6 +1782,20 @@ static inline void add_kallsyms(struct module *mod, } #endif /* CONFIG_KALLSYMS */ +static void *module_alloc_update_bounds(unsigned long size) +{ + void *ret = module_alloc(size); + + if (ret) { + /* Update module bounds. */ + if ((unsigned long)ret < module_addr_min) + module_addr_min = (unsigned long)ret; + if ((unsigned long)ret + size > module_addr_max) + module_addr_max = (unsigned long)ret + size; + } + return ret; +} + /* Allocate and load the module: note that size of section 0 is always zero, and we rely on this for optional sections. */ static struct module *load_module(void __user *umod, @@ -1980,7 +1997,7 @@ static struct module *load_module(void __user *umod, layout_sections(mod, hdr, sechdrs, secstrings); /* Do the allocs. */ - ptr = module_alloc(mod->core_size); + ptr = module_alloc_update_bounds(mod->core_size); if (!ptr) { err = -ENOMEM; goto free_percpu; @@ -1988,7 +2005,7 @@ static struct module *load_module(void __user *umod, memset(ptr, 0, mod->core_size); mod->module_core = ptr; - ptr = module_alloc(mod->init_size); + ptr = module_alloc_update_bounds(mod->init_size); if (!ptr && mod->init_size) { err = -ENOMEM; goto free_core; @@ -2645,6 +2662,9 @@ struct module *__module_text_address(unsigned long addr) { struct module *mod; + if (addr < module_addr_min || addr > module_addr_max) + return NULL; + list_for_each_entry(mod, &modules, list) if (within(addr, mod->module_init, mod->init_text_size) || within(addr, mod->module_core, mod->core_text_size)) -- cgit v1.2.3 From a1ef5adb4cad43460ebba23c5a78cf4a55bb6a5b Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 8 Jul 2008 19:00:17 +0200 Subject: remove CONFIG_KMOD from core kernel code Always compile request_module when the kernel allows modules. Signed-off-by: Johannes Berg Signed-off-by: Rusty Russell --- kernel/exec_domain.c | 2 +- kernel/kmod.c | 2 +- kernel/sysctl.c | 4 ++-- 3 files changed, 4 insertions(+), 4 deletions(-) (limited to 'kernel') diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c index a9e6bad9f70..c1ef192aa65 100644 --- a/kernel/exec_domain.c +++ b/kernel/exec_domain.c @@ -65,7 +65,7 @@ lookup_exec_domain(u_long personality) goto out; } -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES read_unlock(&exec_domains_lock); request_module("personality-%ld", pers); read_lock(&exec_domains_lock); diff --git a/kernel/kmod.c b/kernel/kmod.c index 8df97d3dfda..90d7af1c165 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -42,7 +42,7 @@ extern int max_threads; static struct workqueue_struct *khelper_wq; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES /* modprobe_path is set via /proc/sys. diff --git a/kernel/sysctl.c b/kernel/sysctl.c index 6b16e16428d..b859e6b5a76 100644 --- a/kernel/sysctl.c +++ b/kernel/sysctl.c @@ -110,7 +110,7 @@ static int min_percpu_pagelist_fract = 8; static int ngroups_max = NGROUPS_MAX; -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES extern char modprobe_path[]; #endif #ifdef CONFIG_CHR_DEV_SG @@ -475,7 +475,7 @@ static struct ctl_table kern_table[] = { .proc_handler = &ftrace_enable_sysctl, }, #endif -#ifdef CONFIG_KMOD +#ifdef CONFIG_MODULES { .ctl_name = KERN_MODPROBE, .procname = "modprobe", -- cgit v1.2.3 From 91cd4d6ef0abb1f65e81f8fe37e7d3c10344e38c Mon Sep 17 00:00:00 2001 From: Miao Xie Date: Mon, 21 Jul 2008 14:21:35 -0700 Subject: cpusets: fix wrong domain attr updates Fix wrong domain attr updates, or we will always update the first sched domain attr. Signed-off-by: Miao Xie Cc: Hidetoshi Seto Cc: Paul Jackson Cc: Nick Piggin Cc: Ingo Molnar Cc: [2.6.26.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/cpuset.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/cpuset.c b/kernel/cpuset.c index 459d601947a..d2cc67dac8b 100644 --- a/kernel/cpuset.c +++ b/kernel/cpuset.c @@ -679,7 +679,9 @@ restart: if (apn == b->pn) { cpus_or(*dp, *dp, b->cpus_allowed); b->pn = -1; - update_domain_attr(dattr, b); + if (dattr) + update_domain_attr(dattr + + nslot, b); } } nslot++; -- cgit v1.2.3 From 5f17156fc55abac476d180e480bedb0f07f01b14 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Mon, 21 Jul 2008 14:21:37 -0700 Subject: Fix build on COMPAT platforms when CONFIG_EPOLL is disabled Add missing cond_syscall() entry for compat_sys_epoll_pwait. Signed-off-by: Atsushi Nemoto Cc: Davide Libenzi Cc: [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/sys_ni.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 5b9b467de07..0fea0ee12da 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -59,6 +59,7 @@ cond_syscall(sys_epoll_create); cond_syscall(sys_epoll_ctl); cond_syscall(sys_epoll_wait); cond_syscall(sys_epoll_pwait); +cond_syscall(compat_sys_epoll_pwait); cond_syscall(sys_semget); cond_syscall(sys_semop); cond_syscall(sys_semtimedop); -- cgit v1.2.3 From 2db873211ba47ef704c301f9ecf4a33413a0b649 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Uwe=20Kleine-K=C3=B6nig?= Date: Wed, 23 Jul 2008 14:42:25 +0200 Subject: set_irq_wake: fix return code and wake status tracking MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Since 15a647eba94c3da27ccc666bea72e7cca06b2d19 set_irq_wake returned -ENXIO if another device had it already enabled. Zero is the right value to return in this case. Moreover the change to desc->status was not reverted if desc->chip->set_wake returned an error. Signed-off-by: Uwe Kleine-König Acked-by: David Brownell Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Russell King Cc: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/irq/manage.c | 39 +++++++++++++++++++++++++++------------ 1 file changed, 27 insertions(+), 12 deletions(-) (limited to 'kernel') diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c index 77a51be3601..3cfc0fefb5e 100644 --- a/kernel/irq/manage.c +++ b/kernel/irq/manage.c @@ -217,6 +217,17 @@ void enable_irq(unsigned int irq) } EXPORT_SYMBOL(enable_irq); +int set_irq_wake_real(unsigned int irq, unsigned int on) +{ + struct irq_desc *desc = irq_desc + irq; + int ret = -ENXIO; + + if (desc->chip->set_wake) + ret = desc->chip->set_wake(irq, on); + + return ret; +} + /** * set_irq_wake - control irq power management wakeup * @irq: interrupt to control @@ -233,30 +244,34 @@ int set_irq_wake(unsigned int irq, unsigned int on) { struct irq_desc *desc = irq_desc + irq; unsigned long flags; - int ret = -ENXIO; - int (*set_wake)(unsigned, unsigned) = desc->chip->set_wake; + int ret = 0; /* wakeup-capable irqs can be shared between drivers that * don't need to have the same sleep mode behaviors. */ spin_lock_irqsave(&desc->lock, flags); if (on) { - if (desc->wake_depth++ == 0) - desc->status |= IRQ_WAKEUP; - else - set_wake = NULL; + if (desc->wake_depth++ == 0) { + ret = set_irq_wake_real(irq, on); + if (ret) + desc->wake_depth = 0; + else + desc->status |= IRQ_WAKEUP; + } } else { if (desc->wake_depth == 0) { printk(KERN_WARNING "Unbalanced IRQ %d " "wake disable\n", irq); WARN_ON(1); - } else if (--desc->wake_depth == 0) - desc->status &= ~IRQ_WAKEUP; - else - set_wake = NULL; + } else if (--desc->wake_depth == 0) { + ret = set_irq_wake_real(irq, on); + if (ret) + desc->wake_depth = 1; + else + desc->status &= ~IRQ_WAKEUP; + } } - if (set_wake) - ret = desc->chip->set_wake(irq, on); + spin_unlock_irqrestore(&desc->lock, flags); return ret; } -- cgit v1.2.3 From 86a1c34a929f30fde8ad01ea8245df61ddcf58b7 Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Mon, 23 Jun 2008 15:37:04 -0700 Subject: x86_64 syscall audit fast-path This adds a fast path for 64-bit syscall entry and exit when TIF_SYSCALL_AUDIT is set, but no other kind of syscall tracing. This path does not need to save and restore all registers as the general case of tracing does. Avoiding the iret return path when syscall audit is enabled helps performance a lot. Signed-off-by: Roland McGrath --- kernel/auditsc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/auditsc.c b/kernel/auditsc.c index c10e7aae04d..4699950e65b 100644 --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -1476,7 +1476,8 @@ void audit_syscall_entry(int arch, int major, struct audit_context *context = tsk->audit_context; enum audit_state state; - BUG_ON(!context); + if (unlikely(!context)) + return; /* * This happens only on certain architectures that make system -- cgit v1.2.3