diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/futex_compat.c | 9 | ||||
| -rw-r--r-- | kernel/kallsyms.c | 3 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 16 | ||||
| -rw-r--r-- | kernel/time/timer_stats.c | 44 | ||||
| -rw-r--r-- | kernel/timer.c | 10 |
5 files changed, 58 insertions, 24 deletions
diff --git a/kernel/futex_compat.c b/kernel/futex_compat.c index 338a9b489fb..27478948b31 100644 --- a/kernel/futex_compat.c +++ b/kernel/futex_compat.c @@ -144,20 +144,21 @@ asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val, struct timespec ts; ktime_t t, *tp = NULL; int val2 = 0; + int cmd = op & FUTEX_CMD_MASK; - if (utime && (op == FUTEX_WAIT || op == FUTEX_LOCK_PI)) { + if (utime && (cmd == FUTEX_WAIT || cmd == FUTEX_LOCK_PI)) { if (get_compat_timespec(&ts, utime)) return -EFAULT; if (!timespec_valid(&ts)) return -EINVAL; t = timespec_to_ktime(ts); - if (op == FUTEX_WAIT) + if (cmd == FUTEX_WAIT) t = ktime_add(ktime_get(), t); tp = &t; } - if (op == FUTEX_REQUEUE || op == FUTEX_CMP_REQUEUE - || op == FUTEX_CMP_REQUEUE_PI) + if (cmd == FUTEX_REQUEUE || cmd == FUTEX_CMP_REQUEUE + || cmd == FUTEX_CMP_REQUEUE_PI) val2 = (int) (unsigned long) utime; return do_futex(uaddr, op, val, tp, uaddr2, val2, val3); diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index f1bda23140b..fed54418626 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -257,7 +257,8 @@ const char *kallsyms_lookup(unsigned long addr, pos = get_symbol_pos(addr, symbolsize, offset); /* Grab name */ kallsyms_expand_symbol(get_symbol_offset(pos), namebuf); - *modname = NULL; + if (modname) + *modname = NULL; return namebuf; } diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 3e7ebc4646b..52db9e3c526 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -247,6 +247,21 @@ void tick_nohz_stop_sched_tick(void) if (cpu == tick_do_timer_cpu) tick_do_timer_cpu = -1; + ts->idle_sleeps++; + + /* + * delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that + * there is no timer pending or at least extremly far + * into the future (12 days for HZ=1000). In this case + * we simply stop the tick timer: + */ + if (unlikely(delta_jiffies >= NEXT_TIMER_MAX_DELTA)) { + ts->idle_expires.tv64 = KTIME_MAX; + if (ts->nohz_mode == NOHZ_MODE_HIGHRES) + hrtimer_cancel(&ts->sched_timer); + goto out; + } + /* * calculate the expiry time for the next timer wheel * timer @@ -254,7 +269,6 @@ void tick_nohz_stop_sched_tick(void) expires = ktime_add_ns(last_update, tick_period.tv64 * delta_jiffies); ts->idle_expires = expires; - ts->idle_sleeps++; if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { hrtimer_start(&ts->sched_timer, expires, diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c index 868f1bceb07..321693724ad 100644 --- a/kernel/time/timer_stats.c +++ b/kernel/time/timer_stats.c @@ -117,21 +117,6 @@ static struct entry entries[MAX_ENTRIES]; static atomic_t overflow_count; -static void reset_entries(void) -{ - nr_entries = 0; - memset(entries, 0, sizeof(entries)); - atomic_set(&overflow_count, 0); -} - -static struct entry *alloc_entry(void) -{ - if (nr_entries >= MAX_ENTRIES) - return NULL; - - return entries + nr_entries++; -} - /* * The entries are in a hash-table, for fast lookup: */ @@ -149,6 +134,22 @@ static struct entry *alloc_entry(void) static struct entry *tstat_hash_table[TSTAT_HASH_SIZE] __read_mostly; +static void reset_entries(void) +{ + nr_entries = 0; + memset(entries, 0, sizeof(entries)); + memset(tstat_hash_table, 0, sizeof(tstat_hash_table)); + atomic_set(&overflow_count, 0); +} + +static struct entry *alloc_entry(void) +{ + if (nr_entries >= MAX_ENTRIES) + return NULL; + + return entries + nr_entries++; +} + static int match_entries(struct entry *entry1, struct entry *entry2) { return entry1->timer == entry2->timer && @@ -202,12 +203,15 @@ static struct entry *tstat_lookup(struct entry *entry, char *comm) if (curr) { *curr = *entry; curr->count = 0; + curr->next = NULL; memcpy(curr->comm, comm, TASK_COMM_LEN); + + smp_mb(); /* Ensure that curr is initialized before insert */ + if (prev) prev->next = curr; else *head = curr; - curr->next = NULL; } out_unlock: spin_unlock(&table_lock); @@ -232,10 +236,15 @@ void timer_stats_update_stats(void *timer, pid_t pid, void *startf, /* * It doesnt matter which lock we take: */ - spinlock_t *lock = &per_cpu(lookup_lock, raw_smp_processor_id()); + spinlock_t *lock; struct entry *entry, input; unsigned long flags; + if (likely(!active)) + return; + + lock = &per_cpu(lookup_lock, raw_smp_processor_id()); + input.timer = timer; input.start_func = startf; input.expire_func = timerf; @@ -360,6 +369,7 @@ static ssize_t tstats_write(struct file *file, const char __user *buf, if (!active) { reset_entries(); time_start = ktime_get(); + smp_mb(); active = 1; } break; diff --git a/kernel/timer.c b/kernel/timer.c index 5ec5490f8d8..1a69705c2fb 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -666,7 +666,7 @@ static inline void __run_timers(tvec_base_t *base) static unsigned long __next_timer_interrupt(tvec_base_t *base) { unsigned long timer_jiffies = base->timer_jiffies; - unsigned long expires = timer_jiffies + (LONG_MAX >> 1); + unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA; int index, slot, array, found = 0; struct timer_list *nte; tvec_t *varray[4]; @@ -752,6 +752,14 @@ static unsigned long cmp_next_hrtimer_event(unsigned long now, tsdelta = ktime_to_timespec(hr_delta); delta = timespec_to_jiffies(&tsdelta); + + /* + * Limit the delta to the max value, which is checked in + * tick_nohz_stop_sched_tick(): + */ + if (delta > NEXT_TIMER_MAX_DELTA) + delta = NEXT_TIMER_MAX_DELTA; + /* * Take rounding errors in to account and make sure, that it * expires in the next tick. Otherwise we go into an endless |