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2011-03-14thp+memcg-numa: fix BUG at include/linux/mm.h:370!Hugh Dickins
THP's collapse_huge_page() has an understandable but ugly difference in when its huge page is allocated: inside if NUMA but outside if not. It's hardly surprising that the memcg failure path forgot that, freeing the page in the non-NUMA case, then hitting a VM_BUG_ON in get_page() (or even worse, using the freed page). Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-14exportfs: Return the minimum required handle sizeAneesh Kumar K.V
The exportfs encode handle function should return the minimum required handle size. This helps user to find out the handle size by passing 0 handle size in the first step and then redoing to the call again with the returned handle size value. Acked-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-13thp: fix page_referenced to modify mapcount/vm_flags only if page is foundAndrea Arcangeli
When vmscan.c calls page_referenced(), if an anon page was created before a process forked, rmap will search for it in both of the processes, even though one of them might have since broken COW. If the child process mlocks the vma where the COWed page belongs to, page_referenced() running on the page mapped by the parent would lead to *vm_flags getting VM_LOCKED set erroneously (leading to the references on the parent page being ignored and evicting the parent page too early). *mapcount would also be decremented by page_referenced_one even if the page wasn't found by page_check_address. This also lets pmdp_clear_flush_young_notify() go ahead on a pmd_trans_splitting() pmd. We hold the page_table_lock so __split_huge_page_map() must wait the pmdp_clear_flush_young_notify() to complete before it can modify the pmd. The pmd is also still mapped in userland so the young bit may materialize through a tlb miss before split_huge_page_map runs. This will provide a more accurate page_referenced() behavior during split_huge_page(). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Michel Lespinasse <walken@google.com> Reviewed-by: Michel Lespinasse <walken@google.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel<riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-11Merge branch 'slab/urgent' into slab/nextPekka Enberg
2011-03-11Merge branch 'slab/rcu' into slab/nextPekka Enberg
Conflicts: mm/slub.c
2011-03-11slab,rcu: don't assume the size of struct rcu_headLai Jiangshan
The size of struct rcu_head may be changed. When it becomes larger, it may pollute the data after struct slab. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11slub,rcu: don't assume the size of struct rcu_headLai Jiangshan
The size of struct rcu_head may be changed. When it becomes larger, it will pollute the page array. We reserve some some bytes for struct rcu_head when a slab is allocated in this situation. Changed from V1: use VM_BUG_ON instead BUG_ON Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11slub: automatically reserve bytes at the end of slabLai Jiangshan
There is no "struct" for slub's slab, it shares with struct page. But struct page is very small, it is insufficient when we need to add some metadata for slab. So we add a field "reserved" to struct kmem_cache, when a slab is allocated, kmem_cache->reserved bytes are automatically reserved at the end of the slab for slab's metadata. Changed from v1: Export the reserved field via sysfs Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11Lockless (and preemptless) fastpaths for slubChristoph Lameter
Use the this_cpu_cmpxchg_double functionality to implement a lockless allocation algorithm on arches that support fast this_cpu_ops. Each of the per cpu pointers is paired with a transaction id that ensures that updates of the per cpu information can only occur in sequence on a certain cpu. A transaction id is a "long" integer that is comprised of an event number and the cpu number. The event number is incremented for every change to the per cpu state. This means that the cmpxchg instruction can verify for an update that nothing interfered and that we are updating the percpu structure for the processor where we picked up the information and that we are also currently on that processor when we update the information. This results in a significant decrease of the overhead in the fastpaths. It also makes it easy to adopt the fast path for realtime kernels since this is lockless and does not require the use of the current per cpu area over the critical section. It is only important that the per cpu area is current at the beginning of the critical section and at the end. So there is no need even to disable preemption. Test results show that the fastpath cycle count is reduced by up to ~ 40% (alloc/free test goes from ~140 cycles down to ~80). The slowpath for kfree adds a few cycles. Sadly this does nothing for the slowpath which is where the main issues with performance in slub are but the best case performance rises significantly. (For that see the more complex slub patches that require cmpxchg_double) Kmalloc: alloc/free test Before: 10000 times kmalloc(8)/kfree -> 134 cycles 10000 times kmalloc(16)/kfree -> 152 cycles 10000 times kmalloc(32)/kfree -> 144 cycles 10000 times kmalloc(64)/kfree -> 142 cycles 10000 times kmalloc(128)/kfree -> 142 cycles 10000 times kmalloc(256)/kfree -> 132 cycles 10000 times kmalloc(512)/kfree -> 132 cycles 10000 times kmalloc(1024)/kfree -> 135 cycles 10000 times kmalloc(2048)/kfree -> 135 cycles 10000 times kmalloc(4096)/kfree -> 135 cycles 10000 times kmalloc(8192)/kfree -> 144 cycles 10000 times kmalloc(16384)/kfree -> 754 cycles After: 10000 times kmalloc(8)/kfree -> 78 cycles 10000 times kmalloc(16)/kfree -> 78 cycles 10000 times kmalloc(32)/kfree -> 82 cycles 10000 times kmalloc(64)/kfree -> 88 cycles 10000 times kmalloc(128)/kfree -> 79 cycles 10000 times kmalloc(256)/kfree -> 79 cycles 10000 times kmalloc(512)/kfree -> 85 cycles 10000 times kmalloc(1024)/kfree -> 82 cycles 10000 times kmalloc(2048)/kfree -> 82 cycles 10000 times kmalloc(4096)/kfree -> 85 cycles 10000 times kmalloc(8192)/kfree -> 82 cycles 10000 times kmalloc(16384)/kfree -> 706 cycles Kmalloc: Repeatedly allocate then free test Before: 10000 times kmalloc(8) -> 211 cycles kfree -> 113 cycles 10000 times kmalloc(16) -> 174 cycles kfree -> 115 cycles 10000 times kmalloc(32) -> 235 cycles kfree -> 129 cycles 10000 times kmalloc(64) -> 222 cycles kfree -> 120 cycles 10000 times kmalloc(128) -> 343 cycles kfree -> 139 cycles 10000 times kmalloc(256) -> 827 cycles kfree -> 147 cycles 10000 times kmalloc(512) -> 1048 cycles kfree -> 272 cycles 10000 times kmalloc(1024) -> 2043 cycles kfree -> 528 cycles 10000 times kmalloc(2048) -> 4002 cycles kfree -> 571 cycles 10000 times kmalloc(4096) -> 7740 cycles kfree -> 628 cycles 10000 times kmalloc(8192) -> 8062 cycles kfree -> 850 cycles 10000 times kmalloc(16384) -> 8895 cycles kfree -> 1249 cycles After: 10000 times kmalloc(8) -> 190 cycles kfree -> 129 cycles 10000 times kmalloc(16) -> 76 cycles kfree -> 123 cycles 10000 times kmalloc(32) -> 126 cycles kfree -> 124 cycles 10000 times kmalloc(64) -> 181 cycles kfree -> 128 cycles 10000 times kmalloc(128) -> 310 cycles kfree -> 140 cycles 10000 times kmalloc(256) -> 809 cycles kfree -> 165 cycles 10000 times kmalloc(512) -> 1005 cycles kfree -> 269 cycles 10000 times kmalloc(1024) -> 1999 cycles kfree -> 527 cycles 10000 times kmalloc(2048) -> 3967 cycles kfree -> 570 cycles 10000 times kmalloc(4096) -> 7658 cycles kfree -> 637 cycles 10000 times kmalloc(8192) -> 8111 cycles kfree -> 859 cycles 10000 times kmalloc(16384) -> 8791 cycles kfree -> 1173 cycles Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-11slub: Get rid of slab_free_hook_irq()Christoph Lameter
The following patch will make the fastpaths lockless and will no longer require interrupts to be disabled. Calling the free hook with irq disabled will no longer be possible. Move the slab_free_hook_irq() logic into slab_free_hook. Only disable interrupts if the features are selected that require callbacks with interrupts off and reenable after calls have been made. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-03-10Merge branch 'for-2.6.39/stack-plug' into for-2.6.39/coreJens Axboe
Conflicts: block/blk-core.c block/blk-flush.c drivers/md/raid1.c drivers/md/raid10.c drivers/md/raid5.c fs/nilfs2/btnode.c fs/nilfs2/mdt.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: kill off REQ_UNPLUGJens Axboe
With the plugging now being explicitly controlled by the submitter, callers need not pass down unplugging hints to the block layer. If they want to unplug, it's because they manually plugged on their own - in which case, they should just unplug at will. Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10read-ahead: use pluggingJens Axboe
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10fs: make generic file read/write functions plugJens Axboe
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-10block: remove per-queue pluggingJens Axboe
Code has been converted over to the new explicit on-stack plugging, and delay users have been converted to use the new API for that. So lets kill off the old plugging along with aops->sync_page(). Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2011-03-08Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into nextJames Morris
2011-03-05mm: use correct numa policy node for transparent hugepagesAndi Kleen
Pass down the correct node for a transparent hugepage allocation. Most callers continue to use the current node, however the hugepaged daemon now uses the previous node of the first to be collapsed page instead. This ensures that khugepaged does not mess up local memory for an existing process which uses local policy. The choice of node is somewhat primitive currently: it just uses the node of the first page in the pmd range. An alternative would be to look at multiple pages and use the most popular node. I used the simplest variant for now which should work well enough for the case of all pages being on the same node. [akpm@linux-foundation.org: coding-style fixes] Acked-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-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>
2011-03-05mm: preserve original node for transparent huge page copiesAndi Kleen
This makes a difference for LOCAL policy, where the node cannot be determined from the policy itself, but has to be gotten from the original page. Acked-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-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>
2011-03-05mm: change alloc_pages_vma to pass down the policy node for local policyAndi Kleen
Currently alloc_pages_vma() always uses the local node as policy node for the LOCAL policy. Pass this node down as an argument instead. No behaviour change from this patch, but will be needed for followons. Acked-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-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>
2011-03-01Remove one to many n's in a wordJustin P. Mattock
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-02-27slub: fix ksize() build errorMariusz Kozlowski
mm/slub.c: In function 'ksize': mm/slub.c:2728: error: implicit declaration of function 'slab_ksize' slab_ksize() needs to go out of CONFIG_SLUB_DEBUG section. Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mariusz Kozlowski <mk@lab.zgora.pl> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-02-26mm: Move early_node_map[] reverse scan helpers under HAVE_MEMBLOCKYinghai Lu
Heiko found recent memblock change triggers these warnings on s390: mm/page_alloc.c:3623:22: warning: 'last_active_region_index_in_nid' defined but not used mm/page_alloc.c:3638:22: warning: 'previous_active_region_index_in_nid' defined but not used Need to move those two function under HAVE_MEMBLOCK with its only user, find_memory_core_early(). -tj: Minor updates to description. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-25memcg: more mem_cgroup_uncharge() batchingHugh Dickins
It seems odd that truncate_inode_pages_range(), called not only when truncating but also when evicting inodes, has mem_cgroup_uncharge_start and _end() batching in its second loop to clear up a few leftovers, but not in its first loop that does almost all the work: add them there too. Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25thp: fix interleaving for transparent hugepagesAndi Kleen
The THP code didn't pass the correct interleaving shift to the memory policy code. Fix this here by adjusting for the order. Signed-off-by: Andi Kleen <ak@linux.intel.com> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25mm: fix dubious code in __count_immobile_pages()Namhyung Kim
When pfn_valid_within() failed 'iter' was incremented twice. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25mm: vmscan: stop reclaim/compaction earlier due to insufficient progress if ↵Mel Gorman
!__GFP_REPEAT should_continue_reclaim() for reclaim/compaction allows scanning to continue even if pages are not being reclaimed until the full list is scanned. In terms of allocation success, this makes sense but potentially it introduces unwanted latency for high-order allocations such as transparent hugepages and network jumbo frames that would prefer to fail the allocation attempt and fallback to order-0 pages. Worse, there is a potential that the full LRU scan will clear all the young bits, distort page aging information and potentially push pages into swap that would have otherwise remained resident. This patch will stop reclaim/compaction if no pages were reclaimed in the last SWAP_CLUSTER_MAX pages that were considered. For allocations such as hugetlbfs that use __GFP_REPEAT and have fewer fallback options, the full LRU list may still be scanned. Order-0 allocation should not be affected because RECLAIM_MODE_COMPACTION is not set so the following avoids the gfp_mask being examined: if (!(sc->reclaim_mode & RECLAIM_MODE_COMPACTION)) return false; A tool was developed based on ftrace that tracked the latency of high-order allocations while transparent hugepage support was enabled and three benchmarks were run. The "fix-infinite" figures are 2.6.38-rc4 with Johannes's patch "vmscan: fix zone shrinking exit when scan work is done" applied. STREAM Highorder Allocation Latency Statistics fix-infinite break-early 1 :: Count 10298 10229 1 :: Min 0.4560 0.4640 1 :: Mean 1.0589 1.0183 1 :: Max 14.5990 11.7510 1 :: Stddev 0.5208 0.4719 2 :: Count 2 1 2 :: Min 1.8610 3.7240 2 :: Mean 3.4325 3.7240 2 :: Max 5.0040 3.7240 2 :: Stddev 1.5715 0.0000 9 :: Count 111696 111694 9 :: Min 0.5230 0.4110 9 :: Mean 10.5831 10.5718 9 :: Max 38.4480 43.2900 9 :: Stddev 1.1147 1.1325 Mean time for order-1 allocations is reduced. order-2 looks increased but with so few allocations, it's not particularly significant. THP mean allocation latency is also reduced. That said, allocation time varies so significantly that the reductions are within noise. Max allocation time is reduced by a significant amount for low-order allocations but reduced for THP allocations which presumably are now breaking before reclaim has done enough work. SysBench Highorder Allocation Latency Statistics fix-infinite break-early 1 :: Count 15745 15677 1 :: Min 0.4250 0.4550 1 :: Mean 1.1023 1.0810 1 :: Max 14.4590 10.8220 1 :: Stddev 0.5117 0.5100 2 :: Count 1 1 2 :: Min 3.0040 2.1530 2 :: Mean 3.0040 2.1530 2 :: Max 3.0040 2.1530 2 :: Stddev 0.0000 0.0000 9 :: Count 2017 1931 9 :: Min 0.4980 0.7480 9 :: Mean 10.4717 10.3840 9 :: Max 24.9460 26.2500 9 :: Stddev 1.1726 1.1966 Again, mean time for order-1 allocations is reduced while order-2 allocations are too few to draw conclusions from. The mean time for THP allocations is also slightly reduced albeit the reductions are within varianes. Once again, our maximum allocation time is significantly reduced for low-order allocations and slightly increased for THP allocations. Anon stream mmap reference Highorder Allocation Latency Statistics 1 :: Count 1376 1790 1 :: Min 0.4940 0.5010 1 :: Mean 1.0289 0.9732 1 :: Max 6.2670 4.2540 1 :: Stddev 0.4142 0.2785 2 :: Count 1 - 2 :: Min 1.9060 - 2 :: Mean 1.9060 - 2 :: Max 1.9060 - 2 :: Stddev 0.0000 - 9 :: Count 11266 11257 9 :: Min 0.4990 0.4940 9 :: Mean 27250.4669 24256.1919 9 :: Max 11439211.0000 6008885.0000 9 :: Stddev 226427.4624 186298.1430 This benchmark creates one thread per CPU which references an amount of anonymous memory 1.5 times the size of physical RAM. This pounds swap quite heavily and is intended to exercise THP a bit. Mean allocation time for order-1 is reduced as before. It's also reduced for THP allocations but the variations here are pretty massive due to swap. As before, maximum allocation times are significantly reduced. Overall, the patch reduces the mean and maximum allocation latencies for the smaller high-order allocations. This was with Slab configured so it would be expected to be more significant with Slub which uses these size allocations more aggressively. The mean allocation times for THP allocations are also slightly reduced. The maximum latency was slightly increased as predicted by the comments due to reclaim/compaction breaking early. However, workloads care more about the latency of lower-order allocations than THP so it's an acceptable trade-off. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Kent Overstreet <kent.overstreet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-25mm: grab rcu read lock in move_pages()Greg Thelen
The move_pages() usage of find_task_by_vpid() requires rcu_read_lock() to prevent free_pid() from reclaiming the pid. Without this patch, RCU warnings are printed in v2.6.38-rc4 move_pages() with: CONFIG_LOCKUP_DETECTOR=y CONFIG_PREEMPT=y CONFIG_LOCKDEP=y CONFIG_PROVE_LOCKING=y CONFIG_PROVE_RCU=y Previously, migrate_pages() went through a similar transformation replacing usage of tasklist_lock with rcu read lock: commit 55cfaa3cbdd29c4919ecb5fb8965c310f357e48c Author: Zeng Zhaoming <zengzm.kernel@gmail.com> Date: Thu Dec 2 14:31:13 2010 -0800 mm/mempolicy.c: add rcu read lock to protect pid structure commit 1e50df39f6e2c3a4a3394df62baa8a213df16c54 Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Date: Thu Jan 13 15:46:14 2011 -0800 mempolicy: remove tasklist_lock from migrate_pages Signed-off-by: Greg Thelen <gthelen@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Zeng Zhaoming <zengzm.kernel@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-24mm: fix refcounting in swaponMiklos Szeredi
Grab a reference to bdev before calling blkdev_get(), which expects the refcount to be already incremented and either returns success or decrements the refcount and returns an error. The bug was introduced by e525fd89 (block: make blkdev_get/put() handle exclusive access), which didn't take into account this behavior of blkdev_get(). Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-24bootmem: Move __alloc_memory_core_early() to nobootmem.cYinghai Lu
Now that bootmem.c and nobootmem.c are separate, there's no reason to define __alloc_memory_core_early(), which is used only by nobootmem, inside #ifdef in page_alloc.c. Move it to nobootmem.c and make it static. This patch doesn't introduce any behavior change. -tj: Updated commit description. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-24bootmem: Move contig_page_data definition to bootmem.c/nobootmem.cYinghai Lu
Now that bootmem.c and nobootmem.c are separate, it's cleaner to define contig_page_data in each file than in page_alloc.c with #ifdef. Move it. This patch doesn't introduce any behavior change. -v2: According to Andrew, fixed the struct layout. -tj: Updated commit description. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-24bootmem: Separate out CONFIG_NO_BOOTMEM code into nobootmem.cYinghai Lu
mm/bootmem.c contained code paths for both bootmem and no bootmem configurations. They implement about the same set of APIs in different ways and as a result bootmem.c contains massive amount of #ifdef CONFIG_NO_BOOTMEM. Separate out CONFIG_NO_BOOTMEM code into mm/nobootmem.c. As the common part is relatively small, duplicate them in nobootmem.c instead of creating a common file or ifdef'ing in bootmem.c. The followings are duplicated. * {min|max}_low_pfn, max_pfn, saved_max_pfn * free_bootmem_late() * ___alloc_bootmem() * __alloc_bootmem_low() The followings are applicable only to nobootmem and moved verbatim. * __free_pages_memory() * free_all_memory_core_early() The followings are not applicable to nobootmem and omitted in nobootmem.c. * reserve_bootmem_node() * reserve_bootmem() The rest split function bodies according to CONFIG_NO_BOOTMEM. Makefile is updated so that only either bootmem.c or nobootmem.c is built according to CONFIG_NO_BOOTMEM. This patch doesn't introduce any behavior change. -tj: Rewrote commit description. Suggested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-24mm: fix possible cause of a page_mapped BUGHugh Dickins
Robert Swiecki reported a BUG_ON(page_mapped) from a fuzzer, punching a hole with madvise(,, MADV_REMOVE). That path is under mutex, and cannot be explained by lack of serialization in unmap_mapping_range(). Reviewing the code, I found one place where vm_truncate_count handling should have been updated, when I switched at the last minute from one way of managing the restart_addr to another: mremap move changes the virtual addresses, so it ought to adjust the restart_addr. But rather than exporting the notion of restart_addr from memory.c, or converting to restart_pgoff throughout, simply reset vm_truncate_count to 0 to force a rescan if mremap move races with preempted truncation. We have no confirmation that this fixes Robert's BUG, but it is a fix that's worth making anyway. Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-24mm: prevent concurrent unmap_mapping_range() on the same inodeMiklos Szeredi
Michael Leun reported that running parallel opens on a fuse filesystem can trigger a "kernel BUG at mm/truncate.c:475" Gurudas Pai reported the same bug on NFS. The reason is, unmap_mapping_range() is not prepared for more than one concurrent invocation per inode. For example: thread1: going through a big range, stops in the middle of a vma and stores the restart address in vm_truncate_count. thread2: comes in with a small (e.g. single page) unmap request on the same vma, somewhere before restart_address, finds that the vma was already unmapped up to the restart address and happily returns without doing anything. Another scenario would be two big unmap requests, both having to restart the unmapping and each one setting vm_truncate_count to its own value. This could go on forever without any of them being able to finish. Truncate and hole punching already serialize with i_mutex. Other callers of unmap_mapping_range() do not, and it's difficult to get i_mutex protection for all callers. In particular ->d_revalidate(), which calls invalidate_inode_pages2_range() in fuse, may be called with or without i_mutex. This patch adds a new mutex to 'struct address_space' to prevent running multiple concurrent unmap_mapping_range() on the same mapping. [ We'll hopefully get rid of all this with the upcoming mm preemptibility series by Peter Zijlstra, the "mm: Remove i_mmap_mutex lockbreak" patch in particular. But that is for 2.6.39 ] Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reported-by: Michael Leun <lkml20101129@newton.leun.net> Reported-by: Gurudas Pai <gurudas.pai@oracle.com> Tested-by: Gurudas Pai <gurudas.pai@oracle.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-23slub: fix kmemcheck calls to match ksize() hintsEric Dumazet
Recent use of ksize() in network stack (commit ca44ac38 : net: don't reallocate skb->head unless the current one hasn't the needed extra size or is shared) triggers kmemcheck warnings, because ksize() can return more space than kmemcheck is aware of. Pekka Enberg noticed SLAB+kmemcheck is doing the right thing, while SLUB +kmemcheck doesnt. Bugzilla reference #27212 Reported-by: Christian Casteyde <casteyde.christian@free.fr> Suggested-by: Pekka Enberg <penberg@kernel.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Christoph Lameter <cl@linux.com> CC: Changli Gao <xiaosuo@gmail.com> CC: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-02-17mm: Fix out-of-date comments which refers non-existent functionsRyota Ozaki
do_file_page and do_no_page don't exist anymore, but some comments still refers them. The patch fixes them by replacing them with existing ones. Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-02-15thp: prevent hugepages during args/env copying into the user stackAndrea Arcangeli
Transparent hugepages can only be created if rmap is fully functional. So we must prevent hugepages to be created while is_vma_temporary_stack() is true. This also optmizes away some harmless but unnecessary setting of khugepaged_scan.address and it switches some BUG_ON to VM_BUG_ON. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-14Revert "slab: Fix missing DEBUG_SLAB last user"Pekka Enberg
This reverts commit 5c5e3b33b7cb959a401f823707bee006caadd76e. The commit breaks ARM thusly: | Mount-cache hash table entries: 512 | slab error in verify_redzone_free(): cache `idr_layer_cache': memory outside object was overwritten | Backtrace: | [<c0227088>] (dump_backtrace+0x0/0x110) from [<c0431afc>] (dump_stack+0x18/0x1c) | [<c0431ae4>] (dump_stack+0x0/0x1c) from [<c0293304>] (__slab_error+0x28/0x30) | [<c02932dc>] (__slab_error+0x0/0x30) from [<c0293a74>] (cache_free_debugcheck+0x1c0/0x2b8) | [<c02938b4>] (cache_free_debugcheck+0x0/0x2b8) from [<c0293f78>] (kmem_cache_free+0x3c/0xc0) | [<c0293f3c>] (kmem_cache_free+0x0/0xc0) from [<c032b1c8>] (ida_get_new_above+0x19c/0x1c0) | [<c032b02c>] (ida_get_new_above+0x0/0x1c0) from [<c02af7ec>] (alloc_vfsmnt+0x54/0x144) | [<c02af798>] (alloc_vfsmnt+0x0/0x144) from [<c0299830>] (vfs_kern_mount+0x30/0xec) | [<c0299800>] (vfs_kern_mount+0x0/0xec) from [<c0299908>] (kern_mount_data+0x1c/0x20) | [<c02998ec>] (kern_mount_data+0x0/0x20) from [<c02146c4>] (sysfs_init+0x68/0xc8) | [<c021465c>] (sysfs_init+0x0/0xc8) from [<c02137d4>] (mnt_init+0x90/0x1b0) | [<c0213744>] (mnt_init+0x0/0x1b0) from [<c0213388>] (vfs_caches_init+0x100/0x140) | [<c0213288>] (vfs_caches_init+0x0/0x140) from [<c0208c0c>] (start_kernel+0x2e8/0x368) | [<c0208924>] (start_kernel+0x0/0x368) from [<c0208034>] (__enable_mmu+0x0/0x2c) | c0113268: redzone 1:0xd84156c5c032b3ac, redzone 2:0xd84156c5635688c0. | slab error in cache_alloc_debugcheck_after(): cache `idr_layer_cache': double free, or memory outside object was overwritten | ... | c011307c: redzone 1:0x9f91102ffffffff, redzone 2:0x9f911029d74e35b | slab: Internal list corruption detected in cache 'idr_layer_cache'(24), slabp c0113000(16). Hexdump: | | 000: 20 4f 10 c0 20 4f 10 c0 7c 00 00 00 7c 30 11 c0 | 010: 10 00 00 00 10 00 00 00 00 00 c9 17 fe ff ff ff | 020: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff | 030: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff | 040: fe ff ff ff fe ff ff ff fe ff ff ff fe ff ff ff | 050: fe ff ff ff fe ff ff ff fe ff ff ff 11 00 00 00 | 060: 12 00 00 00 13 00 00 00 14 00 00 00 15 00 00 00 | 070: 16 00 00 00 17 00 00 00 c0 88 56 63 | kernel BUG at /home/rmk/git/linux-2.6-rmk/mm/slab.c:2928! Reference: https://lkml.org/lkml/2011/2/7/238 Cc: <stable@kernel.org> # 2.6.35.y and later Reported-and-analyzed-by: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2011-02-14Merge branch 'linus' into x86/bootmemIngo Molnar
Conflicts: arch/x86/mm/numa_64.c Merge reason: fix the conflict, update to latest -rc and pick up this dependent fix from Yinghai: e6d2e2b2b1e1: memblock: don't adjust size in memblock_find_base() Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-12memcg: fix leak of accounting at failure path of hugepage collapsingKAMEZAWA Hiroyuki
mem_cgroup_uncharge_page() should be called in all failure cases after mem_cgroup_charge_newpage() is called in huge_memory.c::collapse_huge_page() [ 4209.076861] BUG: Bad page state in process khugepaged pfn:1e9800 [ 4209.077601] page:ffffea0006b14000 count:0 mapcount:0 mapping: (null) index:0x2800 [ 4209.078674] page flags: 0x40000000004000(head) [ 4209.079294] pc:ffff880214a30000 pc->flags:2146246697418756 pc->mem_cgroup:ffffc9000177a000 [ 4209.082177] (/A) [ 4209.082500] Pid: 31, comm: khugepaged Not tainted 2.6.38-rc3-mm1 #1 [ 4209.083412] Call Trace: [ 4209.083678] [<ffffffff810f4454>] ? bad_page+0xe4/0x140 [ 4209.084240] [<ffffffff810f53e6>] ? free_pages_prepare+0xd6/0x120 [ 4209.084837] [<ffffffff8155621d>] ? rwsem_down_failed_common+0xbd/0x150 [ 4209.085509] [<ffffffff810f5462>] ? __free_pages_ok+0x32/0xe0 [ 4209.086110] [<ffffffff810f552b>] ? free_compound_page+0x1b/0x20 [ 4209.086699] [<ffffffff810fad6c>] ? __put_compound_page+0x1c/0x30 [ 4209.087333] [<ffffffff810fae1d>] ? put_compound_page+0x4d/0x200 [ 4209.087935] [<ffffffff810fb015>] ? put_page+0x45/0x50 [ 4209.097361] [<ffffffff8113f779>] ? khugepaged+0x9e9/0x1430 [ 4209.098364] [<ffffffff8107c870>] ? autoremove_wake_function+0x0/0x40 [ 4209.099121] [<ffffffff8113ed90>] ? khugepaged+0x0/0x1430 [ 4209.099780] [<ffffffff8107c236>] ? kthread+0x96/0xa0 [ 4209.100452] [<ffffffff8100dda4>] ? kernel_thread_helper+0x4/0x10 [ 4209.101214] [<ffffffff8107c1a0>] ? kthread+0x0/0xa0 [ 4209.101842] [<ffffffff8100dda0>] ? kernel_thread_helper+0x0/0x10 Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-12vmscan: fix zone shrinking exit when scan work is doneJohannes Weiner
Commit 3e7d34497067 ("mm: vmscan: reclaim order-0 and use compaction instead of lumpy reclaim") introduced an indefinite loop in shrink_zone(). It meant to break out of this loop when no pages had been reclaimed and not a single page was even scanned. The way it would detect the latter is by taking a snapshot of sc->nr_scanned at the beginning of the function and comparing it against the new sc->nr_scanned after the scan loop. But it would re-iterate without updating that snapshot, looping forever if sc->nr_scanned changed at least once since shrink_zone() was invoked. This is not the sole condition that would exit that loop, but it requires other processes to change the zone state, as the reclaimer that is stuck obviously can not anymore. This is only happening for higher-order allocations, where reclaim is run back to back with compaction. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Michal Hocko <mhocko@suse.cz> Tested-by: Kent Overstreet<kent.overstreet@gmail.com> Reported-by: Kent Overstreet <kent.overstreet@gmail.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-12mlock: do not munlock pages in __do_fault()Michel Lespinasse
If the page is going to be written to, __do_page needs to break COW. However, the old page (before breaking COW) was never mapped mapped into the current pte (__do_fault is only called when the pte is not present), so vmscan can't have marked the old page as PageMlocked due to being mapped in __do_fault's VMA. Therefore, __do_fault() does not need to worry about clearing PageMlocked() on the old page. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-12mlock: fix race when munlocking pages in do_wp_page()Michel Lespinasse
vmscan can lazily find pages that are mapped within VM_LOCKED vmas, and set the PageMlocked bit on these pages, transfering them onto the unevictable list. When do_wp_page() breaks COW within a VM_LOCKED vma, it may need to clear PageMlocked on the old page and set it on the new page instead. This change fixes an issue where do_wp_page() was clearing PageMlocked on the old page while the pte was still pointing to it (as well as rmap). Therefore, we were not protected against vmscan immediately transfering the old page back onto the unevictable list. This could cause pages to get stranded there forever. I propose to move the corresponding code to the end of do_wp_page(), after the pte (and rmap) have been pointed to the new page. Additionally, we can use munlock_vma_page() instead of clear_page_mlock(), so that the old page stays mlocked if there are still other VM_LOCKED vmas mapping it. Signed-off-by: Michel Lespinasse <walken@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-12memblock: don't adjust size in memblock_find_base()Yinghai Lu
While applying patch to use memblock to find aperture for 64bit x86. Ingo found system with 1g + force_iommu > No AGP bridge found > Node 0: aperture @ 38000000 size 32 MB > Aperture pointing to e820 RAM. Ignoring. > Your BIOS doesn't leave a aperture memory hole > Please enable the IOMMU option in the BIOS setup > This costs you 64 MB of RAM > Cannot allocate aperture memory hole (0,65536K) the corresponding code: addr = memblock_find_in_range(0, 1ULL<<32, aper_size, 512ULL<<20); if (addr == MEMBLOCK_ERROR || addr + aper_size > 0xffffffff) { printk(KERN_ERR "Cannot allocate aperture memory hole (%lx,%uK)\n", addr, aper_size>>10); return 0; } memblock_x86_reserve_range(addr, addr + aper_size, "aperture64") fails because memblock core code align the size with 512M. That could make size way too big. So don't align the size in that case. actually __memblock_alloc_base, the another caller already align that before calling that function. BTW. x86 does not use __memblock_alloc_base... Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Dave Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03memcg: fix event counting breakage from recent THP updateKAMEZAWA Hiroyuki
Changes in e401f1761 ("memcg: modify accounting function for supporting THP better") adds nr_pages to support multiple page size in memory_cgroup_charge_statistics. But counting the number of event nees abs(nr_pages) for increasing counters. This patch fixes event counting. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03memcg: never OOM when charging huge pagesJohannes Weiner
Huge page coverage should obviously have less priority than the continued execution of a process. Never kill a process when charging it a huge page fails. Instead, give up after the first failed reclaim attempt and fall back to regular pages. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03memcg: prevent endless loop when charging huge pages to near-limit groupJohannes Weiner
If reclaim after a failed charging was unsuccessful, the limits are checked again, just in case they settled by means of other tasks. This is all fine as long as every charge is of size PAGE_SIZE, because in that case, being below the limit means having at least PAGE_SIZE bytes available. But with transparent huge pages, we may end up in an endless loop where charging and reclaim fail, but we keep going because the limits are not yet exceeded, although not allowing for a huge page. Fix this up by explicitely checking for enough room, not just whether we are within limits. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03memcg: prevent endless loop when charging huge pagesJohannes Weiner
The charging code can encounter a charge size that is bigger than a regular page in two situations: one is a batched charge to fill the per-cpu stocks, the other is a huge page charge. This code is distributed over two functions, however, and only the outer one is aware of huge pages. In case the charging fails, the inner function will tell the outer function to retry if the charge size is bigger than regular pages--assuming batched charging is the only case. And the outer function will retry forever charging a huge page. This patch makes sure the inner function can distinguish between batch charging and a single huge page charge. It will only signal another attempt if batch charging failed, and go into regular reclaim when it is called on behalf of a huge page. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03thp: fix unsuitable behavior for hwpoisoned tail pageJin Dongming
When a tail page of THP is poisoned, memory-failure will do nothing except setting PG_hwpoison, while the expected behavior is that the process, who is using the poisoned tail page, should be killed. The above problem is caused by lru check of the poisoned tail page of THP. Because PG_lru flag is only set on the head page of THP, the check always consider the poisoned tail page as NON lru page. So the lru check for the tail page of THP should be avoided, as like as hugetlb. This patch adds !PageTransCompound() before lru check for THP, because of the check (!PageHuge() && !PageTransCompound()) the whole branch could be optimized away at build time when both hugetlbfs and THP are set with "N" (or in archs not supporting either of those). [akpm@linux-foundation.org: fix unrelated typo in shake_page() comment] Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03thp: fix the wrong reported address of hwpoisoned hugepagesJin Dongming
When the tail page of THP is poisoned, the head page will be poisoned too. And the wrong address, address of head page, will be sent with sigbus always. So when the poisoned page is used by Guest OS which is running on KVM, after the address changing(hva->gpa) by qemu, the unexpected process on Guest OS will be killed by sigbus. What we expected is that the process using the poisoned tail page could be killed on Guest OS, but not that the process using the healthy head page is killed. Since it is not good to poison the healthy page, avoid poisoning other than the page which is really poisoned. (While we poison all pages in a huge page in case of hugetlb, we can do this for THP thanks to split_huge_page().) Here we fix two parts: 1. Isolate the poisoned page only to make sure the reported address is the address of poisoned page. 2. make the poisoned page work as the poisoned regular page. [akpm@linux-foundation.org: fix spello in comment] Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-03thp: fix splitting of hwpoisoned hugepagesJin Dongming
The poisoned THP is now split with split_huge_page() in collect_procs_anon(). If kmalloc() is failed in collect_procs(), split_huge_page() could not be called. And the work after split_huge_page() for collecting the processes using poisoned page will not be done, too. So the processes using the poisoned page could not be killed. The condition becomes worse when CONFIG_DEBUG_VM == "Y". Because the poisoned THP could not be split, system panic will be caused by VM_BUG_ON(PageTransHuge(page)) in try_to_unmap(). This patch does: 1. move split_huge_page() to the place before collect_procs(). This can be sure the failure of splitting THP is caused by itself. 2. when splitting THP is failed, stop the operations after it. This can avoid unexpected system panic or non sense works. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jin Dongming <jin.dongming@np.css.fujitsu.com> Reviewed-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>