xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

perf/core: Robustify the perf_cgroup_from_task() RCU checks

Browse Source 
This patch reinforces the lockdep checks performed by
perf_cgroup_from_tsk() by passing the perf_event_context
whenever possible. It is okay to not hold the RCU read lock
when we know we hold the ctx->lock. This patch makes sure this
property holds.

In some functions, such as perf_cgroup_sched_in(), we do not
pass the context because we are sure we are holding the RCU
read lock.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: edumazet@google.com
Link: http://lkml.kernel.org/r/1447322404-10920-3-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Stephane Eranian
2015-11-12 11:00:04 +01:00
committed by Ingo Molnar
parent ddaaf4e291
commit 614e4c4ebc
3 changed files with 18 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
include/linux/perf_event.h
View File

@@ -697,9 +697,11 @@ struct perf_cgroup {
* if there is no cgroup event for the current CPU context.
*/
static inline struct perf_cgroup *
perf_cgroup_from_task(struct task_struct *task)
perf_cgroup_from_task(struct task_struct *task, struct perf_event_context *ctx)
{
return container_of(task_css(task, perf_event_cgrp_id),
return container_of(task_css_check(task, perf_event_cgrp_id,
ctx ? lockdep_is_held(&ctx->lock)
: true),
struct perf_cgroup, css);
}
#endif /* CONFIG_CGROUP_PERF */