From 1643db98d9b314e0a592d152603094fbf7ab906e Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Mon, 13 Mar 2023 19:28:18 +0800 Subject: mm: vmscan: remove shrinker_rwsem from synchronize_shrinkers() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Currently, the synchronize_shrinkers() is only used by TTM pool. It only requires that no shrinkers run in parallel, and doesn't care about registering and unregistering of shrinkers. Since slab shrink is protected by SRCU, synchronize_srcu() is sufficient to ensure that no shrinker is running in parallel. So the shrinker_rwsem in synchronize_shrinkers() is no longer needed, just remove it. Link: https://lkml.kernel.org/r/20230313112819.38938-8-zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: Vlastimil Babka Acked-by: Kirill Tkhai Acked-by: Roman Gushchin Cc: Christian König Cc: David Hildenbrand Cc: Davidlohr Bueso Cc: Johannes Weiner Cc: Michal Hocko Cc: Muchun Song Cc: Paul E. McKenney Cc: Shakeel Butt Cc: Sultan Alsawaf Cc: Tetsuo Handa Cc: Yang Shi Signed-off-by: Andrew Morton --- mm/vmscan.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) (limited to 'mm/vmscan.c') diff --git a/mm/vmscan.c b/mm/vmscan.c index 8c1ae7ea8dea..2b22a42d83c4 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -790,15 +790,11 @@ EXPORT_SYMBOL(unregister_shrinker); /** * synchronize_shrinkers - Wait for all running shrinkers to complete. * - * This is equivalent to calling unregister_shrink() and register_shrinker(), - * but atomically and with less overhead. This is useful to guarantee that all - * shrinker invocations have seen an update, before freeing memory, similar to - * rcu. + * This is useful to guarantee that all shrinker invocations have seen an + * update, before freeing memory. */ void synchronize_shrinkers(void) { - down_write(&shrinker_rwsem); - up_write(&shrinker_rwsem); atomic_inc(&shrinker_srcu_generation); synchronize_srcu(&shrinker_srcu); } -- cgit