locking/mutex, sched/wait: Add mutex_lock_io()
authorTejun Heo <tj@kernel.org>
Fri, 28 Oct 2016 16:58:11 +0000 (12:58 -0400)
committerIngo Molnar <mingo@kernel.org>
Sat, 14 Jan 2017 10:30:05 +0000 (11:30 +0100)
commit1460cb65a10f6c7a6e3a1c76513338861a0a43b6
tree15c9773a766aea95828a609976a7bb8ba5dbbfc2
parent10ab56434f2f633a51e432ee8b7c29e12438e163
locking/mutex, sched/wait: Add mutex_lock_io()

We sometimes end up propagating IO blocking through mutexes; however,
because there currently is no way of annotating mutex sleeps as
iowait, there are cases where iowait and /proc/stat:procs_blocked
report misleading numbers obscuring the actual state of the system.

This patch adds mutex_lock_io() so that mutex sleeps can be marked as
iowait in those cases.

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: adilger.kernel@dilger.ca
Cc: jack@suse.com
Cc: kernel-team@fb.com
Cc: mingbo@fb.com
Cc: tytso@mit.edu
Link: http://lkml.kernel.org/r/1477673892-28940-4-git-send-email-tj@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
include/linux/mutex.h
kernel/locking/mutex.c