From f0cb3c76ae1ced85f9034480b1b24cd96530ec78 Mon Sep 17 00:00:00 2001 From: Konstantin Khlebnikov Date: Wed, 21 Mar 2012 16:34:06 -0700 Subject: [PATCH] mm: drain percpu lru add/rotate page-vectors on cpu hot-unplug This cpu hotplug hook was accidentally removed in commit 00a62ce91e55 ("mm: fix Committed_AS underflow on large NR_CPUS environment") The visible effect of this accident: some pages are borrowed in per-cpu page-vectors. Truncate can deal with it, but these pages cannot be reused while this cpu is offline. So this is like a temporary memory leak. Signed-off-by: Konstantin Khlebnikov Cc: Dave Hansen Cc: KOSAKI Motohiro Cc: Eric B Munson Cc: Mel Gorman Cc: Christoph Lameter Cc: KAMEZAWA Hiroyuki Cc: Johannes Weiner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/swap.h | 1 + mm/page_alloc.c | 1 + mm/swap.c | 4 ++-- 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/swap.h b/include/linux/swap.h index 64a7dba67840..b86b5c20617d 100644 --- a/include/linux/swap.h +++ b/include/linux/swap.h @@ -223,6 +223,7 @@ extern void lru_add_page_tail(struct zone* zone, extern void activate_page(struct page *); extern void mark_page_accessed(struct page *); extern void lru_add_drain(void); +extern void lru_add_drain_cpu(int cpu); extern int lru_add_drain_all(void); extern void rotate_reclaimable_page(struct page *page); extern void deactivate_page(struct page *page); diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 98552cf1da8b..673596ad9c80 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -4825,6 +4825,7 @@ static int page_alloc_cpu_notify(struct notifier_block *self, int cpu = (unsigned long)hcpu; if (action == CPU_DEAD || action == CPU_DEAD_FROZEN) { + lru_add_drain_cpu(cpu); drain_pages(cpu); /* diff --git a/mm/swap.c b/mm/swap.c index 14380e9fbe33..5c13f1338972 100644 --- a/mm/swap.c +++ b/mm/swap.c @@ -496,7 +496,7 @@ static void lru_deactivate_fn(struct page *page, void *arg) * Either "cpu" is the current CPU, and preemption has already been * disabled; or "cpu" is being hot-unplugged, and is already dead. */ -static void drain_cpu_pagevecs(int cpu) +void lru_add_drain_cpu(int cpu) { struct pagevec *pvecs = per_cpu(lru_add_pvecs, cpu); struct pagevec *pvec; @@ -553,7 +553,7 @@ void deactivate_page(struct page *page) void lru_add_drain(void) { - drain_cpu_pagevecs(get_cpu()); + lru_add_drain_cpu(get_cpu()); put_cpu(); } -- 2.39.5