locking/lockdep: Rework FS_RECLAIM annotation

A while ago someone, and I cannot find the email just now, asked if we
could not implement the RECLAIM_FS inversion stuff with a 'fake' lock
like we use for other things like workqueues etc. I think this should
be possible which allows reducing the 'irq' states and will reduce the
amount of __bfs() lookups we do.

Removing the 1 IRQ state results in 4 less __bfs() walks per
dependency, improving lockdep performance. And by moving this
annotation out of the lockdep code it becomes easier for the mm people
to extend.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Nikolay Borisov <nborisov@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: akpm@linux-foundation.org
Cc: boqun.feng@gmail.com
Cc: iamjoonsoo.kim@lge.com
Cc: kernel-team@lge.com
Cc: kirill@shutemov.name
Cc: npiggin@gmail.com
Cc: walken@google.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 5 insertions, 1 deletions

diff --git a/mm/slab.h b/mm/slab.h
index 6885e1192ec5..073362816acc 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -43,6 +43,7 @@ struct kmem_cache {
 #include <linux/kasan.h>
 #include <linux/kmemleak.h>
 #include <linux/random.h>
+#include <linux/sched/mm.h>
 
 /*
  * State of the slab allocator.
@@ -412,7 +413,10 @@ static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
 						     gfp_t flags)
 {
 	flags &= gfp_allowed_mask;
-	lockdep_trace_alloc(flags);
+
+	fs_reclaim_acquire(flags);
+	fs_reclaim_release(flags);
+
 	might_sleep_if(gfpflags_allow_blocking(flags));
 
 	if (should_failslab(s, flags))