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-rw-r--r--arch/i386/kernel/tsc.c1
-rw-r--r--drivers/acpi/processor_idle.c32
-rw-r--r--fs/proc/array.c44
-rw-r--r--include/linux/sched.h5
-rw-r--r--kernel/sched.c68
-rw-r--r--kernel/sched_debug.c3
6 files changed, 110 insertions, 43 deletions
diff --git a/arch/i386/kernel/tsc.c b/arch/i386/kernel/tsc.c
index debd7dbb415..a39280b4dd3 100644
--- a/arch/i386/kernel/tsc.c
+++ b/arch/i386/kernel/tsc.c
@@ -292,7 +292,6 @@ static struct clocksource clocksource_tsc = {
void mark_tsc_unstable(char *reason)
{
- sched_clock_unstable_event();
if (!tsc_unstable) {
tsc_unstable = 1;
tsc_enabled = 0;
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index a8634a0655f..d9b8af763e1 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -63,6 +63,7 @@
ACPI_MODULE_NAME("processor_idle");
#define ACPI_PROCESSOR_FILE_POWER "power"
#define US_TO_PM_TIMER_TICKS(t) ((t * (PM_TIMER_FREQUENCY/1000)) / 1000)
+#define PM_TIMER_TICK_NS (1000000000ULL/PM_TIMER_FREQUENCY)
#define C2_OVERHEAD 4 /* 1us (3.579 ticks per us) */
#define C3_OVERHEAD 4 /* 1us (3.579 ticks per us) */
static void (*pm_idle_save) (void) __read_mostly;
@@ -462,6 +463,9 @@ static void acpi_processor_idle(void)
* TBD: Can't get time duration while in C1, as resumes
* go to an ISR rather than here. Need to instrument
* base interrupt handler.
+ *
+ * Note: the TSC better not stop in C1, sched_clock() will
+ * skew otherwise.
*/
sleep_ticks = 0xFFFFFFFF;
break;
@@ -469,6 +473,8 @@ static void acpi_processor_idle(void)
case ACPI_STATE_C2:
/* Get start time (ticks) */
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
+ /* Tell the scheduler that we are going deep-idle: */
+ sched_clock_idle_sleep_event();
/* Invoke C2 */
acpi_state_timer_broadcast(pr, cx, 1);
acpi_cstate_enter(cx);
@@ -479,17 +485,22 @@ static void acpi_processor_idle(void)
/* TSC halts in C2, so notify users */
mark_tsc_unstable("possible TSC halt in C2");
#endif
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2);
+
+ /* Tell the scheduler how much we idled: */
+ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
+
/* Re-enable interrupts */
local_irq_enable();
+ /* Do not account our idle-switching overhead: */
+ sleep_ticks -= cx->latency_ticks + C2_OVERHEAD;
+
current_thread_info()->status |= TS_POLLING;
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks =
- ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
case ACPI_STATE_C3:
-
/*
* disable bus master
* bm_check implies we need ARB_DIS
@@ -518,6 +529,8 @@ static void acpi_processor_idle(void)
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Invoke C3 */
acpi_state_timer_broadcast(pr, cx, 1);
+ /* Tell the scheduler that we are going deep-idle: */
+ sched_clock_idle_sleep_event();
acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
@@ -531,12 +544,17 @@ static void acpi_processor_idle(void)
/* TSC halts in C3, so notify users */
mark_tsc_unstable("TSC halts in C3");
#endif
+ /* Compute time (ticks) that we were actually asleep */
+ sleep_ticks = ticks_elapsed(t1, t2);
+ /* Tell the scheduler how much we idled: */
+ sched_clock_idle_wakeup_event(sleep_ticks*PM_TIMER_TICK_NS);
+
/* Re-enable interrupts */
local_irq_enable();
+ /* Do not account our idle-switching overhead: */
+ sleep_ticks -= cx->latency_ticks + C3_OVERHEAD;
+
current_thread_info()->status |= TS_POLLING;
- /* Compute time (ticks) that we were actually asleep */
- sleep_ticks =
- ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
diff --git a/fs/proc/array.c b/fs/proc/array.c
index 965625a0977..ee4814dd98f 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -320,7 +320,21 @@ int proc_pid_status(struct task_struct *task, char *buffer)
return buffer - orig;
}
-static clock_t task_utime(struct task_struct *p)
+/*
+ * Use precise platform statistics if available:
+ */
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING
+static cputime_t task_utime(struct task_struct *p)
+{
+ return p->utime;
+}
+
+static cputime_t task_stime(struct task_struct *p)
+{
+ return p->stime;
+}
+#else
+static cputime_t task_utime(struct task_struct *p)
{
clock_t utime = cputime_to_clock_t(p->utime),
total = utime + cputime_to_clock_t(p->stime);
@@ -337,10 +351,10 @@ static clock_t task_utime(struct task_struct *p)
}
utime = (clock_t)temp;
- return utime;
+ return clock_t_to_cputime(utime);
}
-static clock_t task_stime(struct task_struct *p)
+static cputime_t task_stime(struct task_struct *p)
{
clock_t stime;
@@ -349,10 +363,12 @@ static clock_t task_stime(struct task_struct *p)
* the total, to make sure the total observed by userspace
* grows monotonically - apps rely on that):
*/
- stime = nsec_to_clock_t(p->se.sum_exec_runtime) - task_utime(p);
+ stime = nsec_to_clock_t(p->se.sum_exec_runtime) -
+ cputime_to_clock_t(task_utime(p));
- return stime;
+ return clock_t_to_cputime(stime);
}
+#endif
static int do_task_stat(struct task_struct *task, char *buffer, int whole)
{
@@ -368,8 +384,7 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
unsigned long long start_time;
unsigned long cmin_flt = 0, cmaj_flt = 0;
unsigned long min_flt = 0, maj_flt = 0;
- cputime_t cutime, cstime;
- clock_t utime, stime;
+ cputime_t cutime, cstime, utime, stime;
unsigned long rsslim = 0;
char tcomm[sizeof(task->comm)];
unsigned long flags;
@@ -387,8 +402,7 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
sigemptyset(&sigign);
sigemptyset(&sigcatch);
- cutime = cstime = cputime_zero;
- utime = stime = 0;
+ cutime = cstime = utime = stime = cputime_zero;
rcu_read_lock();
if (lock_task_sighand(task, &flags)) {
@@ -414,15 +428,15 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
do {
min_flt += t->min_flt;
maj_flt += t->maj_flt;
- utime += task_utime(t);
- stime += task_stime(t);
+ utime = cputime_add(utime, task_utime(t));
+ stime = cputime_add(stime, task_stime(t));
t = next_thread(t);
} while (t != task);
min_flt += sig->min_flt;
maj_flt += sig->maj_flt;
- utime += cputime_to_clock_t(sig->utime);
- stime += cputime_to_clock_t(sig->stime);
+ utime = cputime_add(utime, sig->utime);
+ stime = cputime_add(stime, sig->stime);
}
sid = signal_session(sig);
@@ -471,8 +485,8 @@ static int do_task_stat(struct task_struct *task, char *buffer, int whole)
cmin_flt,
maj_flt,
cmaj_flt,
- utime,
- stime,
+ cputime_to_clock_t(utime),
+ cputime_to_clock_t(stime),
cputime_to_clock_t(cutime),
cputime_to_clock_t(cstime),
priority,
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 682ef87da6e..ba78807eab9 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -681,7 +681,7 @@ enum cpu_idle_type {
#define SCHED_LOAD_SHIFT 10
#define SCHED_LOAD_SCALE (1L << SCHED_LOAD_SHIFT)
-#define SCHED_LOAD_SCALE_FUZZ (SCHED_LOAD_SCALE >> 1)
+#define SCHED_LOAD_SCALE_FUZZ SCHED_LOAD_SCALE
#ifdef CONFIG_SMP
#define SD_LOAD_BALANCE 1 /* Do load balancing on this domain. */
@@ -1388,7 +1388,8 @@ extern void sched_exec(void);
#define sched_exec() {}
#endif
-extern void sched_clock_unstable_event(void);
+extern void sched_clock_idle_sleep_event(void);
+extern void sched_clock_idle_wakeup_event(u64 delta_ns);
#ifdef CONFIG_HOTPLUG_CPU
extern void idle_task_exit(void);
diff --git a/kernel/sched.c b/kernel/sched.c
index 45e17b83b7f..96e9b82246d 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -262,7 +262,8 @@ struct rq {
s64 clock_max_delta;
unsigned int clock_warps, clock_overflows;
- unsigned int clock_unstable_events;
+ u64 idle_clock;
+ unsigned int clock_deep_idle_events;
u64 tick_timestamp;
atomic_t nr_iowait;
@@ -556,18 +557,40 @@ static inline struct rq *this_rq_lock(void)
}
/*
- * CPU frequency is/was unstable - start new by setting prev_clock_raw:
+ * We are going deep-idle (irqs are disabled):
*/
-void sched_clock_unstable_event(void)
+void sched_clock_idle_sleep_event(void)
{
- unsigned long flags;
- struct rq *rq;
+ struct rq *rq = cpu_rq(smp_processor_id());
- rq = task_rq_lock(current, &flags);
- rq->prev_clock_raw = sched_clock();
- rq->clock_unstable_events++;
- task_rq_unlock(rq, &flags);
+ spin_lock(&rq->lock);
+ __update_rq_clock(rq);
+ spin_unlock(&rq->lock);
+ rq->clock_deep_idle_events++;
}
+EXPORT_SYMBOL_GPL(sched_clock_idle_sleep_event);
+
+/*
+ * We just idled delta nanoseconds (called with irqs disabled):
+ */
+void sched_clock_idle_wakeup_event(u64 delta_ns)
+{
+ struct rq *rq = cpu_rq(smp_processor_id());
+ u64 now = sched_clock();
+
+ rq->idle_clock += delta_ns;
+ /*
+ * Override the previous timestamp and ignore all
+ * sched_clock() deltas that occured while we idled,
+ * and use the PM-provided delta_ns to advance the
+ * rq clock:
+ */
+ spin_lock(&rq->lock);
+ rq->prev_clock_raw = now;
+ rq->clock += delta_ns;
+ spin_unlock(&rq->lock);
+}
+EXPORT_SYMBOL_GPL(sched_clock_idle_wakeup_event);
/*
* resched_task - mark a task 'to be rescheduled now'.
@@ -2494,7 +2517,7 @@ group_next:
* a think about bumping its value to force at least one task to be
* moved
*/
- if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task/2) {
+ if (*imbalance + SCHED_LOAD_SCALE_FUZZ < busiest_load_per_task) {
unsigned long tmp, pwr_now, pwr_move;
unsigned int imbn;
@@ -3020,6 +3043,7 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
struct sched_domain *sd;
/* Earliest time when we have to do rebalance again */
unsigned long next_balance = jiffies + 60*HZ;
+ int update_next_balance = 0;
for_each_domain(cpu, sd) {
if (!(sd->flags & SD_LOAD_BALANCE))
@@ -3056,8 +3080,10 @@ static inline void rebalance_domains(int cpu, enum cpu_idle_type idle)
if (sd->flags & SD_SERIALIZE)
spin_unlock(&balancing);
out:
- if (time_after(next_balance, sd->last_balance + interval))
+ if (time_after(next_balance, sd->last_balance + interval)) {
next_balance = sd->last_balance + interval;
+ update_next_balance = 1;
+ }
/*
* Stop the load balance at this level. There is another
@@ -3067,7 +3093,14 @@ out:
if (!balance)
break;
}
- rq->next_balance = next_balance;
+
+ /*
+ * next_balance will be updated only when there is a need.
+ * When the cpu is attached to null domain for ex, it will not be
+ * updated.
+ */
+ if (likely(update_next_balance))
+ rq->next_balance = next_balance;
}
/*
@@ -4890,7 +4923,7 @@ static inline void sched_init_granularity(void)
if (sysctl_sched_granularity > gran_limit)
sysctl_sched_granularity = gran_limit;
- sysctl_sched_runtime_limit = sysctl_sched_granularity * 4;
+ sysctl_sched_runtime_limit = sysctl_sched_granularity * 8;
sysctl_sched_wakeup_granularity = sysctl_sched_granularity / 2;
}
@@ -5234,15 +5267,16 @@ static void migrate_dead_tasks(unsigned int dead_cpu)
static struct ctl_table sd_ctl_dir[] = {
{
.procname = "sched_domain",
- .mode = 0755,
+ .mode = 0555,
},
{0,},
};
static struct ctl_table sd_ctl_root[] = {
{
+ .ctl_name = CTL_KERN,
.procname = "kernel",
- .mode = 0755,
+ .mode = 0555,
.child = sd_ctl_dir,
},
{0,},
@@ -5318,7 +5352,7 @@ static ctl_table *sd_alloc_ctl_cpu_table(int cpu)
for_each_domain(cpu, sd) {
snprintf(buf, 32, "domain%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0755;
+ entry->mode = 0555;
entry->child = sd_alloc_ctl_domain_table(sd);
entry++;
i++;
@@ -5338,7 +5372,7 @@ static void init_sched_domain_sysctl(void)
for (i = 0; i < cpu_num; i++, entry++) {
snprintf(buf, 32, "cpu%d", i);
entry->procname = kstrdup(buf, GFP_KERNEL);
- entry->mode = 0755;
+ entry->mode = 0555;
entry->child = sd_alloc_ctl_cpu_table(i);
}
sd_sysctl_header = register_sysctl_table(sd_ctl_root);
diff --git a/kernel/sched_debug.c b/kernel/sched_debug.c
index 87e524762b8..ab18f45f2ab 100644
--- a/kernel/sched_debug.c
+++ b/kernel/sched_debug.c
@@ -154,10 +154,11 @@ static void print_cpu(struct seq_file *m, int cpu)
P(next_balance);
P(curr->pid);
P(clock);
+ P(idle_clock);
P(prev_clock_raw);
P(clock_warps);
P(clock_overflows);
- P(clock_unstable_events);
+ P(clock_deep_idle_events);
P(clock_max_delta);
P(cpu_load[0]);
P(cpu_load[1]);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-03 11:32:48 +0000