diff options
author | Ingo Molnar <mingo@elte.hu> | 2011-02-25 16:09:48 +0100 |
---|---|---|
committer | Ingo Molnar <mingo@elte.hu> | 2011-02-25 16:09:48 +0100 |
commit | ec6f81cffe52d883e97b15dd0207c789bb44a0f1 (patch) | |
tree | edf04aa8d3c0f2a724c56ce9555d29b3bd5cbc0c /kernel | |
parent | 4d2eced3733561ed357d29d19b61061f73ac41ae (diff) | |
parent | 170ae6bc24e1d7f9bd921a484ec9ea2825497970 (diff) |
Merge branch 'perf/core' into auto-latest
Diffstat (limited to 'kernel')
-rw-r--r-- | kernel/perf_event.c | 53 |
1 files changed, 32 insertions, 21 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index a0a6987fabc4..64a018e94fca 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -201,6 +201,11 @@ __get_cpu_context(struct perf_event_context *ctx) #ifdef CONFIG_CGROUP_PERF +/* + * Must ensure cgroup is pinned (css_get) before calling + * this function. In other words, we cannot call this function + * if there is no cgroup event for the current CPU context. + */ static inline struct perf_cgroup * perf_cgroup_from_task(struct task_struct *task) { @@ -268,28 +273,41 @@ static inline void update_cgrp_time_from_cpuctx(struct perf_cpu_context *cpuctx) static inline void update_cgrp_time_from_event(struct perf_event *event) { - struct perf_cgroup *cgrp = perf_cgroup_from_task(current); + struct perf_cgroup *cgrp; + /* - * do not update time when cgroup is not active + * ensure we access cgroup data only when needed and + * when we know the cgroup is pinned (css_get) */ - if (!event->cgrp || cgrp != event->cgrp) + if (!is_cgroup_event(event)) return; - __update_cgrp_time(event->cgrp); + cgrp = perf_cgroup_from_task(current); + /* + * Do not update time when cgroup is not active + */ + if (cgrp == event->cgrp) + __update_cgrp_time(event->cgrp); } static inline void -perf_cgroup_set_timestamp(struct task_struct *task, u64 now) +perf_cgroup_set_timestamp(struct task_struct *task, + struct perf_event_context *ctx) { struct perf_cgroup *cgrp; struct perf_cgroup_info *info; - if (!task) + /* + * ctx->lock held by caller + * ensure we do not access cgroup data + * unless we have the cgroup pinned (css_get) + */ + if (!task || !ctx->nr_cgroups) return; cgrp = perf_cgroup_from_task(task); info = this_cpu_ptr(cgrp->info); - info->timestamp = now; + info->timestamp = ctx->timestamp; } #define PERF_CGROUP_SWOUT 0x1 /* cgroup switch out every event */ @@ -494,7 +512,8 @@ static inline int perf_cgroup_connect(pid_t pid, struct perf_event *event, } static inline void -perf_cgroup_set_timestamp(struct task_struct *task, u64 now) +perf_cgroup_set_timestamp(struct task_struct *task, + struct perf_event_context *ctx) { } @@ -1613,7 +1632,7 @@ static int __perf_event_enable(void *info) /* * set current task's cgroup time reference point */ - perf_cgroup_set_timestamp(current, perf_clock()); + perf_cgroup_set_timestamp(current, ctx); __perf_event_mark_enabled(event, ctx); @@ -2048,7 +2067,7 @@ ctx_sched_in(struct perf_event_context *ctx, now = perf_clock(); ctx->timestamp = now; - perf_cgroup_set_timestamp(task, now); + perf_cgroup_set_timestamp(task, ctx); /* * First go through the list and put on any pinned groups * in order to give them the best chance of going on. @@ -5791,17 +5810,9 @@ static void task_clock_event_del(struct perf_event *event, int flags) static void task_clock_event_read(struct perf_event *event) { - u64 time; - - if (!in_nmi()) { - update_context_time(event->ctx); - update_cgrp_time_from_event(event); - time = event->ctx->time; - } else { - u64 now = perf_clock(); - u64 delta = now - event->ctx->timestamp; - time = event->ctx->time + delta; - } + u64 now = perf_clock(); + u64 delta = now - event->ctx->timestamp; + u64 time = event->ctx->time + delta; task_clock_event_update(event, time); } |