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authorTejun Heo <tj@kernel.org>2016-10-28 12:58:11 -0400
committerIngo Molnar <mingo@kernel.org>2017-01-14 11:30:05 +0100
commit1460cb65a10f6c7a6e3a1c76513338861a0a43b6 (patch)
tree15c9773a766aea95828a609976a7bb8ba5dbbfc2 /kernel/locking
parent10ab56434f2f633a51e432ee8b7c29e12438e163 (diff)
downloadlinux-1460cb65a10f6c7a6e3a1c76513338861a0a43b6.tar.gz
linux-1460cb65a10f6c7a6e3a1c76513338861a0a43b6.tar.xz
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>
Diffstat (limited to 'kernel/locking')
-rw-r--r--kernel/locking/mutex.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c
index 9b349619f431..8464a5cbab97 100644
--- a/kernel/locking/mutex.c
+++ b/kernel/locking/mutex.c
@@ -783,6 +783,20 @@ mutex_lock_interruptible_nested(struct mutex *lock, unsigned int subclass)
}
EXPORT_SYMBOL_GPL(mutex_lock_interruptible_nested);
+void __sched
+mutex_lock_io_nested(struct mutex *lock, unsigned int subclass)
+{
+ int token;
+
+ might_sleep();
+
+ token = io_schedule_prepare();
+ __mutex_lock_common(lock, TASK_UNINTERRUPTIBLE,
+ subclass, NULL, _RET_IP_, NULL, 0);
+ io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(mutex_lock_io_nested);
+
static inline int
ww_mutex_deadlock_injection(struct ww_mutex *lock, struct ww_acquire_ctx *ctx)
{
@@ -950,6 +964,16 @@ int __sched mutex_lock_killable(struct mutex *lock)
}
EXPORT_SYMBOL(mutex_lock_killable);
+void __sched mutex_lock_io(struct mutex *lock)
+{
+ int token;
+
+ token = io_schedule_prepare();
+ mutex_lock(lock);
+ io_schedule_finish(token);
+}
+EXPORT_SYMBOL_GPL(mutex_lock_io);
+
static noinline void __sched
__mutex_lock_slowpath(struct mutex *lock)
{