[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1228339524.6598.11.camel@t60p>
Date: Wed, 03 Dec 2008 22:25:24 +0100
From: Gerald Schaefer <gerald.schaefer@...ibm.com>
To: akpm@...ux-foundation.org
Cc: linux-kernel@...r.kernel.org, linux-mm@...ck.org,
schwidefsky@...ibm.com, heiko.carstens@...ibm.com,
kamezawa.hiroyu@...fujitsu.com, y-goto@...fujitsu.com,
npiggin@...e.de
Subject: [PATCH] memory hotplug: run lru_add_drain_all() on each cpu
From: Gerald Schaefer <gerald.schaefer@...ibm.com>
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.
This is fixed with this patch by adding CONFIG_MEMORY_HOTREMOVE to the
lru_add_drain_all() #ifdef, to let it run on each cpu.
Signed-off-by: Gerald Schaefer <gerald.schaefer@...ibm.com>
---
mm/swap.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
Index: linux-2.6/mm/swap.c
===================================================================
--- linux-2.6.orig/mm/swap.c
+++ linux-2.6/mm/swap.c
@@ -299,7 +299,8 @@ void lru_add_drain(void)
put_cpu();
}
-#if defined(CONFIG_NUMA) || defined(CONFIG_UNEVICTABLE_LRU)
+#if defined(CONFIG_NUMA) || defined(CONFIG_UNEVICTABLE_LRU) || \
+ defined(CONFIG_MEMORY_HOTREMOVE)
static void lru_add_drain_per_cpu(struct work_struct *dummy)
{
lru_add_drain();
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists