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authorPeter Zijlstra <peterz@infradead.org>2017-03-03 12:13:38 +0300
committerIngo Molnar <mingo@kernel.org>2017-08-10 13:29:03 +0300
commitd92a8cfcb37ecd1315269dab741f073b63b3a8b6 (patch)
treebd081c6309a48d23ae074e2035105be13622b005 /include/linux/sched
parenta9668cd6ee288c4838bc668880ac085be551cac2 (diff)
downloadlinux-d92a8cfcb37ecd1315269dab741f073b63b3a8b6.tar.xz
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>
Diffstat (limited to 'include/linux/sched')
-rw-r--r--include/linux/sched/mm.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index 2b24a6974847..2b0a281f9d26 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -167,6 +167,14 @@ static inline gfp_t current_gfp_context(gfp_t flags)
return flags;
}
+#ifdef CONFIG_LOCKDEP
+extern void fs_reclaim_acquire(gfp_t gfp_mask);
+extern void fs_reclaim_release(gfp_t gfp_mask);
+#else
+static inline void fs_reclaim_acquire(gfp_t gfp_mask) { }
+static inline void fs_reclaim_release(gfp_t gfp_mask) { }
+#endif
+
static inline unsigned int memalloc_noio_save(void)
{
unsigned int flags = current->flags & PF_MEMALLOC_NOIO;