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authorPeter Zijlstra <peterz@infradead.org>2016-01-08 11:39:10 +0100
committerIngo Molnar <mingo@kernel.org>2016-01-21 18:54:23 +0100
commit63e30d3e52d4d85854ce6c761ffc6ab55209a630 (patch)
treef0833f9173a358737aadfefe56e7e60bb741b337 /kernel/events/core.c
parent25432ae96a9889774a05bf5f0f6fd8dbcdec5e72 (diff)
downloadlinux-63e30d3e52d4d85854ce6c761ffc6ab55209a630.tar.bz2
perf: Make ctx->is_active and cpuctx->task_ctx consistent
For no apparent reason and to great confusion the rules for ctx->is_active and cpuctx->task_ctx are different. This means that its not always possible to find all active (task) contexts. Fix this such that if ctx->is_active gets set, we also set (or verify) cpuctx->task_ctx. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'kernel/events/core.c')
-rw-r--r--kernel/events/core.c21
1 files changed, 14 insertions, 7 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 935aefd16354..89b47050a2e8 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2329,6 +2329,12 @@ static void ctx_sched_out(struct perf_event_context *ctx,
lockdep_assert_held(&ctx->lock);
ctx->is_active &= ~event_type;
+ if (ctx->task) {
+ WARN_ON_ONCE(cpuctx->task_ctx != ctx);
+ if (!ctx->is_active)
+ cpuctx->task_ctx = NULL;
+ }
+
if (likely(!ctx->nr_events))
return;
@@ -2629,7 +2635,6 @@ static void task_ctx_sched_out(struct perf_cpu_context *cpuctx,
return;
ctx_sched_out(ctx, cpuctx, EVENT_ALL);
- cpuctx->task_ctx = NULL;
}
/*
@@ -2712,6 +2717,13 @@ ctx_sched_in(struct perf_event_context *ctx,
lockdep_assert_held(&ctx->lock);
ctx->is_active |= event_type;
+ if (ctx->task) {
+ if (!is_active)
+ cpuctx->task_ctx = ctx;
+ else
+ WARN_ON_ONCE(cpuctx->task_ctx != ctx);
+ }
+
if (likely(!ctx->nr_events))
return;
@@ -2756,12 +2768,7 @@ static void perf_event_context_sched_in(struct perf_event_context *ctx,
* cpu flexible, task flexible.
*/
cpu_ctx_sched_out(cpuctx, EVENT_FLEXIBLE);
-
- if (ctx->nr_events)
- cpuctx->task_ctx = ctx;
-
- perf_event_sched_in(cpuctx, cpuctx->task_ctx, task);
-
+ perf_event_sched_in(cpuctx, ctx, task);
perf_pmu_enable(ctx->pmu);
perf_ctx_unlock(cpuctx, ctx);
}