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authorGerald Schaefer <gerald.schaefer@de.ibm.com>2008-10-02 14:50:16 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-02 15:53:13 -0700
commit6c1b7f680dd4f550fa6f91f148cc6fa2c4bd0737 (patch)
tree948651742b6fcff5079d555173b60584afb7682d /mm/page_isolation.c
parentaa94fbd5ccd840c8ab26d02439ec799b03a72547 (diff)
downloadlinux-6c1b7f680dd4f550fa6f91f148cc6fa2c4bd0737.tar.gz
memory hotplug: missing zone->lock in test_pages_isolated()
__test_page_isolated_in_pageblock() in mm/page_isolation.c has a comment saying that the caller must hold zone->lock. But the only caller of that function, test_pages_isolated(), does not hold zone->lock and the lock is also not acquired anywhere before. This patch adds the missing zone->lock to test_pages_isolated(). We reproducibly run into BUG_ON(!PageBuddy(page)) in __offline_isolated_pages() during memory hotplug stress test, see trace below. This patch fixes that problem, it would be good if we could have it in 2.6.27. kernel BUG at /home/autobuild/BUILD/linux-2.6.26-20080909/mm/page_alloc.c:4561! illegal operation: 0001 [#1] PREEMPT SMP Modules linked in: dm_multipath sunrpc bonding qeth_l3 dm_mod qeth ccwgroup vmur CPU: 1 Not tainted 2.6.26-29.x.20080909-s390default #1 Process memory_loop_all (pid: 10025, task: 2f444028, ksp: 2b10dd28) Krnl PSW : 040c0000 801727ea (__offline_isolated_pages+0x18e/0x1c4) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:0 CC:0 PM:0 Krnl GPRS: 00000000 7e27fc00 00000000 7e27fc00 00000000 00000400 00014000 7e27fc01 00606f00 7e27fc00 00013fe0 2b10dd28 00000005 80172662 801727b2 2b10dd28 Krnl Code: 801727de: 5810900c l %r1,12(%r9) 801727e2: a7f4ffb3 brc 15,80172748 801727e6: a7f40001 brc 15,801727e8 >801727ea: a7f4ffbc brc 15,80172762 801727ee: a7f40001 brc 15,801727f0 801727f2: a7f4ffaf brc 15,80172750 801727f6: 0707 bcr 0,%r7 801727f8: 0017 unknown Call Trace: ([<0000000000172772>] __offline_isolated_pages+0x116/0x1c4) [<00000000001953a2>] offline_isolated_pages_cb+0x22/0x34 [<000000000013164c>] walk_memory_resource+0xcc/0x11c [<000000000019520e>] offline_pages+0x36a/0x498 [<00000000001004d6>] remove_memory+0x36/0x44 [<000000000028fb06>] memory_block_change_state+0x112/0x150 [<000000000028ffb8>] store_mem_state+0x90/0xe4 [<0000000000289c00>] sysdev_store+0x34/0x40 [<00000000001ee048>] sysfs_write_file+0xd0/0x178 [<000000000019b1a8>] vfs_write+0x74/0x118 [<000000000019b9ae>] sys_write+0x46/0x7c [<000000000011160e>] sysc_do_restart+0x12/0x16 [<0000000077f3e8ca>] 0x77f3e8ca Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/page_isolation.c')
-rw-r--r--mm/page_isolation.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/mm/page_isolation.c b/mm/page_isolation.c
index c69f84fe038..b70a7fec1ff 100644
--- a/mm/page_isolation.c
+++ b/mm/page_isolation.c
@@ -114,8 +114,10 @@ __test_page_isolated_in_pageblock(unsigned long pfn, unsigned long end_pfn)
int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
{
- unsigned long pfn;
+ unsigned long pfn, flags;
struct page *page;
+ struct zone *zone;
+ int ret;
pfn = start_pfn;
/*
@@ -131,7 +133,9 @@ int test_pages_isolated(unsigned long start_pfn, unsigned long end_pfn)
if (pfn < end_pfn)
return -EBUSY;
/* Check all pages are free or Marked as ISOLATED */
- if (__test_page_isolated_in_pageblock(start_pfn, end_pfn))
- return 0;
- return -EBUSY;
+ zone = page_zone(pfn_to_page(pfn));
+ spin_lock_irqsave(&zone->lock, flags);
+ ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn);
+ spin_unlock_irqrestore(&zone->lock, flags);
+ return ret ? 0 : -EBUSY;
}