Commit 6841c8e26357904ef462650273f5d5015f7bb370
Committed by
Linus Torvalds
1 parent
02d2116887
Exists in
master
and in
4 other branches
mm: remove UP version of lru_add_drain_all()
Currently, lru_add_drain_all() has two version. (1) use schedule_on_each_cpu() (2) don't use schedule_on_each_cpu() Gerald Schaefer reported it doesn't work well on SMP (not NUMA) S390 machine. offline_pages() calls lru_add_drain_all() followed by drain_all_pages(). While drain_all_pages() works on each cpu, lru_add_drain_all() only runs on the current cpu for architectures w/o CONFIG_NUMA. This let us run into the BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test on s390. The page in question was still on the pcp list, because of a race with lru_add_drain_all() and drain_all_pages() on different cpus. Actually, Almost machine has CONFIG_UNEVICTABLE_LRU=y. Then almost machine use (1) version lru_add_drain_all although the machine is UP. Then this ifdef is not valueable. simple removing is better. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Acked-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Showing 1 changed file with 0 additions and 13 deletions Side-by-side Diff
mm/swap.c
... | ... | @@ -299,7 +299,6 @@ |
299 | 299 | put_cpu(); |
300 | 300 | } |
301 | 301 | |
302 | -#if defined(CONFIG_NUMA) || defined(CONFIG_UNEVICTABLE_LRU) | |
303 | 302 | static void lru_add_drain_per_cpu(struct work_struct *dummy) |
304 | 303 | { |
305 | 304 | lru_add_drain(); |
... | ... | @@ -312,18 +311,6 @@ |
312 | 311 | { |
313 | 312 | return schedule_on_each_cpu(lru_add_drain_per_cpu); |
314 | 313 | } |
315 | - | |
316 | -#else | |
317 | - | |
318 | -/* | |
319 | - * Returns 0 for success | |
320 | - */ | |
321 | -int lru_add_drain_all(void) | |
322 | -{ | |
323 | - lru_add_drain(); | |
324 | - return 0; | |
325 | -} | |
326 | -#endif | |
327 | 314 | |
328 | 315 | /* |
329 | 316 | * Batched page_cache_release(). Decrement the reference count on all the |