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perf: Set owner pointer for kernel events 

Adding fake EVENT_OWNER_KERNEL owner pointer value for kernel perf
events, so we could distinguish it from user events, which needs
special care in following patch.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1406896382-18404-3-git-send-email-jolsa@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Jiri Olsa 2014-08-01 14:33:01 +02:00 committed by Ingo Molnar
parent 0f7c29ce90
commit f86977620e
1 changed files with 26 additions and 6 deletions
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32
kernel/events/core.c
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@ -119,6 +119,13 @@ static int cpu_function_call(int cpu, int (*func) (void *info), void *info)
return data.ret;
}
#define EVENT_OWNER_KERNEL ((void *) -1)
static bool is_kernel_event(struct perf_event *event)
{
return event->owner == EVENT_OWNER_KERNEL;
}
#define PERF_FLAG_ALL (PERF_FLAG_FD_NO_GROUP |\
PERF_FLAG_FD_OUTPUT |\
PERF_FLAG_PID_CGROUP |\
@ -3312,16 +3319,12 @@ static void free_event(struct perf_event *event)
}
/*
* Called when the last reference to the file is gone.
* Remove user event from the owner task.
*/
static void put_event(struct perf_event *event)
static void perf_remove_from_owner(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
struct task_struct *owner;
if (!atomic_long_dec_and_test(&event->refcount))
return;
rcu_read_lock();
owner = ACCESS_ONCE(event->owner);
/*
@ -3354,6 +3357,20 @@ static void put_event(struct perf_event *event)
mutex_unlock(&owner->perf_event_mutex);
put_task_struct(owner);
}
}
/*
* Called when the last reference to the file is gone.
*/
static void put_event(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
if (!atomic_long_dec_and_test(&event->refcount))
return;
if (!is_kernel_event(event))
perf_remove_from_owner(event);
WARN_ON_ONCE(ctx->parent_ctx);
/*
@ -7366,6 +7383,9 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
goto err;
}
/* Mark owner so we could distinguish it from user events. */
event->owner = EVENT_OWNER_KERNEL;
account_event(event);
ctx = find_get_context(event->pmu, task, cpu);