From e83b39d6bbdb6d25bd6f5c258832774635d29b47 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 15 Nov 2022 13:32:55 +0100 Subject: mm: make drop_caches keep reclaiming on all nodes Currently, drop_caches are reclaiming node-by-node, looping on each node until reclaim could not make progress. This can however leave quite some slab entries (such as filesystem inodes) unreclaimed if objects say on node 1 keep objects on node 0 pinned. So move the "loop until no progress" loop to the node-by-node iteration to retry reclaim also on other nodes if reclaim on some nodes made progress. This fixes problem when drop_caches was not reclaiming lots of otherwise perfectly fine to reclaim inodes. Link: https://lkml.kernel.org/r/20221115123255.12559-1-jack@suse.cz Signed-off-by: Jan Kara Reported-by: You Zhou Reported-by: Pengfei Xu Tested-by: Pengfei Xu Reviewed-by: Shakeel Butt Cc: Vladimir Davydov Signed-off-by: Andrew Morton --- mm/vmscan.c | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/mm/vmscan.c b/mm/vmscan.c index d7c71be6417d..82f32c929b11 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c @@ -1021,31 +1021,34 @@ out: return freed; } -static void drop_slab_node(int nid) +static unsigned long drop_slab_node(int nid) { - unsigned long freed; - int shift = 0; + unsigned long freed = 0; + struct mem_cgroup *memcg = NULL; + memcg = mem_cgroup_iter(NULL, NULL, NULL); do { - struct mem_cgroup *memcg = NULL; - - if (fatal_signal_pending(current)) - return; + freed += shrink_slab(GFP_KERNEL, nid, memcg, 0); + } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); - freed = 0; - memcg = mem_cgroup_iter(NULL, NULL, NULL); - do { - freed += shrink_slab(GFP_KERNEL, nid, memcg, 0); - } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); - } while ((freed >> shift++) > 1); + return freed; } void drop_slab(void) { int nid; + int shift = 0; + unsigned long freed; - for_each_online_node(nid) - drop_slab_node(nid); + do { + freed = 0; + for_each_online_node(nid) { + if (fatal_signal_pending(current)) + return; + + freed += drop_slab_node(nid); + } + } while ((freed >> shift++) > 1); } static int reclaimer_offset(void) -- cgit v1.2.3