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| author | Stephane Eranian <eranian@google.com> | 2015-11-12 11:00:04 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-11-23 09:21:03 +0100 |
| commit | 614e4c4ebc75517295bccd29b20ddbc5b52af6fc (patch) | |
| tree | 67931aaaac4c9e81176140293348f3582ef2a742 /include/linux/perf_event.h | |
| parent | ddaaf4e291dd63db0667991e4a335fcf3a7df13e (diff) | |
| download | op-kernel-dev-614e4c4ebc75517295bccd29b20ddbc5b52af6fc.zip op-kernel-dev-614e4c4ebc75517295bccd29b20ddbc5b52af6fc.tar.gz | |
perf/core: Robustify the perf_cgroup_from_task() RCU checks
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>
Diffstat (limited to 'include/linux/perf_event.h')
| -rw-r--r-- | include/linux/perf_event.h | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index d841d33..f9828a4 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -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 */ |
