Commit-ID: f86977620ee4635f26befcf436700493a38ce002
Gitweb: http://git.kernel.org/tip/f86977620ee4635f26befcf436700493a38ce002
Author: Jiri Olsa <jolsa@xxxxxxxxxx>
AuthorDate: Fri, 1 Aug 2014 14:33:01 +0200
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 13 Aug 2014 07:51:03 +0200
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@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Corey Ashford <cjashfor@xxxxxxxxxxxxxxxxxx>
Cc: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Cc: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1406896382-18404-3-git-send-email-jolsa@xxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
kernel/events/core.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 1cf24b3..bbb3ca2 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -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);
--
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