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authorChris Metcalf <cmetcalf@tilera.com>2013-09-12 15:13:55 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-12 15:38:02 -0700
commit5fbc461636c32efdb9d5216d491d37a40d54535b (patch)
tree119599fe279ba3daf94422d54cfc7bd2a5ae4a80 /include/linux/swap.h
parent9cb2dc1c950cf0624202c1ea2705705e1e51c278 (diff)
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mm: make lru_add_drain_all() selective
make lru_add_drain_all() only selectively interrupt the cpus that have per-cpu free pages that can be drained. This is important in nohz mode where calling mlockall(), for example, otherwise will interrupt every core unnecessarily. This is important on workloads where nohz cores are handling 10 Gb traffic in userspace. Those CPUs do not enter the kernel and place pages into LRU pagevecs and they really, really don't want to be interrupted, or they drop packets on the floor. Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/swap.h')
-rw-r--r--include/linux/swap.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/include/linux/swap.h b/include/linux/swap.h
index c03c139219c9..46ba0c6c219f 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -280,7 +280,7 @@ 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 lru_add_drain_all(void);
extern void rotate_reclaimable_page(struct page *page);
extern void deactivate_page(struct page *page);
extern void swap_setup(void);