diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/events/core.c | 13 | ||||
| -rw-r--r-- | kernel/jump_label.c | 35 |
2 files changed, 41 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c index 3c1541d7a53..3a3b1a18f49 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -128,7 +128,7 @@ enum event_type_t { * perf_sched_events : >0 events exist * perf_cgroup_events: >0 per-cpu cgroup events exist on this cpu */ -struct jump_label_key perf_sched_events __read_mostly; +struct jump_label_key_deferred perf_sched_events __read_mostly; static DEFINE_PER_CPU(atomic_t, perf_cgroup_events); static atomic_t nr_mmap_events __read_mostly; @@ -2748,7 +2748,7 @@ static void free_event(struct perf_event *event) if (!event->parent) { if (event->attach_state & PERF_ATTACH_TASK) - jump_label_dec(&perf_sched_events); + jump_label_dec_deferred(&perf_sched_events); if (event->attr.mmap || event->attr.mmap_data) atomic_dec(&nr_mmap_events); if (event->attr.comm) @@ -2759,7 +2759,7 @@ static void free_event(struct perf_event *event) put_callchain_buffers(); if (is_cgroup_event(event)) { atomic_dec(&per_cpu(perf_cgroup_events, event->cpu)); - jump_label_dec(&perf_sched_events); + jump_label_dec_deferred(&perf_sched_events); } } @@ -5784,7 +5784,7 @@ done: if (!event->parent) { if (event->attach_state & PERF_ATTACH_TASK) - jump_label_inc(&perf_sched_events); + jump_label_inc(&perf_sched_events.key); if (event->attr.mmap || event->attr.mmap_data) atomic_inc(&nr_mmap_events); if (event->attr.comm) @@ -6022,7 +6022,7 @@ SYSCALL_DEFINE5(perf_event_open, * - that may need work on context switch */ atomic_inc(&per_cpu(perf_cgroup_events, event->cpu)); - jump_label_inc(&perf_sched_events); + jump_label_inc(&perf_sched_events.key); } /* @@ -6868,6 +6868,9 @@ void __init perf_event_init(void) ret = init_hw_breakpoint(); WARN(ret, "hw_breakpoint initialization failed with: %d", ret); + + /* do not patch jump label more than once per second */ + jump_label_rate_limit(&perf_sched_events, HZ); } static int __init perf_event_sysfs_init(void) diff --git a/kernel/jump_label.c b/kernel/jump_label.c index 66ff7109f69..51a175ab0a0 100644 --- a/kernel/jump_label.c +++ b/kernel/jump_label.c @@ -72,15 +72,46 @@ void jump_label_inc(struct jump_label_key *key) jump_label_unlock(); } -void jump_label_dec(struct jump_label_key *key) +static void __jump_label_dec(struct jump_label_key *key, + unsigned long rate_limit, struct delayed_work *work) { if (!atomic_dec_and_mutex_lock(&key->enabled, &jump_label_mutex)) return; - jump_label_update(key, JUMP_LABEL_DISABLE); + if (rate_limit) { + atomic_inc(&key->enabled); + schedule_delayed_work(work, rate_limit); + } else + jump_label_update(key, JUMP_LABEL_DISABLE); + jump_label_unlock(); } +static void jump_label_update_timeout(struct work_struct *work) +{ + struct jump_label_key_deferred *key = + container_of(work, struct jump_label_key_deferred, work.work); + __jump_label_dec(&key->key, 0, NULL); +} + +void jump_label_dec(struct jump_label_key *key) +{ + __jump_label_dec(key, 0, NULL); +} + +void jump_label_dec_deferred(struct jump_label_key_deferred *key) +{ + __jump_label_dec(&key->key, key->timeout, &key->work); +} + + +void jump_label_rate_limit(struct jump_label_key_deferred *key, + unsigned long rl) +{ + key->timeout = rl; + INIT_DELAYED_WORK(&key->work, jump_label_update_timeout); +} + static int addr_conflict(struct jump_entry *entry, void *start, void *end) { if (entry->code <= (unsigned long)end && |