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| author | Liu Ping Fan <pingfank@linux.vnet.ibm.com> | 2014-03-04 00:38:39 +0100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-03-04 16:55:50 +0100 |
| commit | 1ae71d03194ea7424cbd14e449581f67c463d20d (patch) | |
| tree | 03ef1d1338596b5aa51c16d9a106f056857efcff /include | |
| parent | MAINTAINERS: add and correct types of some "T:" entries (diff) | |
| download | linux-1ae71d03194ea7424cbd14e449581f67c463d20d.tar.xz linux-1ae71d03194ea7424cbd14e449581f67c463d20d.zip | |
mm: numa: bugfix for LAST_CPUPID_NOT_IN_PAGE_FLAGS
When doing some numa tests on powerpc, I triggered an oops bug. I find
it is caused by using page->_last_cpupid. It should be initialized as
"-1 & LAST_CPUPID_MASK", but not "-1". Otherwise, in task_numa_fault(),
we will miss the checking (last_cpupid == (-1 & LAST_CPUPID_MASK)). And
finally cause an oops bug in task_numa_group(), since the online cpu is
less than possible cpu. This happen with CONFIG_SPARSE_VMEMMAP disabled
Call trace:
SMP NR_CPUS=64 NUMA PowerNV
Modules linked in:
CPU: 24 PID: 804 Comm: systemd-udevd Not tainted3.13.0-rc1+ #32
task: c000001e2746aa80 ti: c000001e32c50000 task.ti:c000001e32c50000
REGS: c000001e32c53510 TRAP: 0300 Not tainted(3.13.0-rc1+)
MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI> CR:28024424 XER: 20000000
CFAR: c000000000009324 DAR: 7265717569726857 DSISR:40000000 SOFTE: 1
NIP .task_numa_fault+0x1470/0x2370
LR .task_numa_fault+0x1468/0x2370
Call Trace:
.task_numa_fault+0x1468/0x2370 (unreliable)
.do_numa_page+0x480/0x4a0
.handle_mm_fault+0x4ec/0xc90
.do_page_fault+0x3a8/0x890
handle_page_fault+0x10/0x30
Instruction dump:
3c82fefb 3884b138 48d9cff1 60000000 48000574 3c62fefb3863af78 3c82fefb
3884b138 48d9cfd5 60000000 e93f0100 <812902e4> 7d2907b45529063e 7d2a07b4
---[ end trace 15f2510da5ae07cf ]---
Signed-off-by: Liu Ping Fan <pingfank@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/mm.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index a1fe25110f50..c1b7414c7bef 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -767,7 +767,7 @@ static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid) #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS static inline int page_cpupid_xchg_last(struct page *page, int cpupid) { - return xchg(&page->_last_cpupid, cpupid); + return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK); } static inline int page_cpupid_last(struct page *page) @@ -776,7 +776,7 @@ static inline int page_cpupid_last(struct page *page) } static inline void page_cpupid_reset_last(struct page *page) { - page->_last_cpupid = -1; + page->_last_cpupid = -1 & LAST_CPUPID_MASK; } #else static inline int page_cpupid_last(struct page *page) |