Commit-ID: aee7dbc45f8aa976913de9b352fa6da816f1f3cd
Gitweb: http://git.kernel.org/tip/aee7dbc45f8aa976913de9b352fa6da816f1f3cd
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Fri, 8 Jan 2016 10:45:11 +0100
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Thu, 21 Jan 2016 18:54:22 +0100
perf: Simplify/fix perf_event_enable() event scheduling
Like perf_enable_on_exec(), perf_event_enable() event scheduling has problems
respecting the context hierarchy when trying to schedule events (for
example, it will try and add a pinned event without first removing
existing flexible events).
So simplify it by using the new ctx_resched() call which will DTRT.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Stephane Eranian <eranian@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Vince Weaver <vincent.weaver@xxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/events/core.c | 31 +++++--------------------------
1 file changed, 5 insertions(+), 26 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 12f1d4a..079eb9f 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2188,7 +2188,7 @@ static int __perf_event_enable(void *info)
struct perf_event_context *ctx = event->ctx;
struct perf_event *leader = event->group_leader;
struct perf_cpu_context *cpuctx = __get_cpu_context(ctx);
- int err;
+ struct perf_event_context *task_ctx = cpuctx->task_ctx;
/*
* There's a time window between 'ctx->is_active' check
@@ -2202,7 +2202,8 @@ static int __perf_event_enable(void *info)
if (!ctx->is_active)
return -EINVAL;
- raw_spin_lock(&ctx->lock);
+ perf_ctx_lock(cpuctx, task_ctx);
+ WARN_ON_ONCE(&cpuctx->ctx != ctx && task_ctx != ctx);
update_context_time(ctx);
if (event->state >= PERF_EVENT_STATE_INACTIVE)
@@ -2228,32 +2229,10 @@ static int __perf_event_enable(void *info)
if (leader != event && leader->state != PERF_EVENT_STATE_ACTIVE)
goto unlock;
- if (!group_can_go_on(event, cpuctx, 1)) {
- err = -EEXIST;
- } else {
- if (event == leader)
- err = group_sched_in(event, cpuctx, ctx);
- else
- err = event_sched_in(event, cpuctx, ctx);
- }
-
- if (err) {
- /*
- * If this event can't go on and it's part of a
- * group, then the whole group has to come off.
- */
- if (leader != event) {
- group_sched_out(leader, cpuctx, ctx);
- perf_mux_hrtimer_restart(cpuctx);
- }
- if (leader->attr.pinned) {
- update_group_times(leader);
- leader->state = PERF_EVENT_STATE_ERROR;
- }
- }
+ ctx_resched(cpuctx, task_ctx);
unlock:
- raw_spin_unlock(&ctx->lock);
+ perf_ctx_unlock(cpuctx, task_ctx);
return 0;
}
--
To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
|