Apparently despite it being marked inline, the compiler
may not inline __down_read_common() which makes it difficult
to identify the cause of lock contention, as the blocked
function in traceevents will always be listed as
__down_read_common().
So this patch adds __always_inline annotation to the common
function (as well as the inlined helper callers) to force it to
be inlined so the blocking function will be listed (via Wchan)
in traceevents.
Fixes: c995e638cc ("locking/rwsem: Fold __down_{read,write}*()")
Reported-by: Tim Murray <timmurray@google.com>
Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20230503023351.2832796-1-jstultz@google.com
Bug: 277817995
(cherry picked from commit 92cc5d00a431e96e5a49c0b97e5ad4fa7536bd4b
https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/urgent)
Signed-off-by: John Stultz <jstultz@google.com>
(cherry picked from https://android-review.googlesource.com/q/commit:a6c75b2e64573cb9f49f6b89808207856fc0309b)
Merged-In: Ifad7ed7fe9f2d5a9eb0cfe7c35e45c0e86bc3ad4
Change-Id: Ifad7ed7fe9f2d5a9eb0cfe7c35e45c0e86bc3ad4
da126f8d02