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* thp+memcg-numa: fix BUG at include/linux/mm.h:370!Hugh Dickins2011-03-14
| | | | | | | | | | | | 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>
* thp: fix page_referenced to modify mapcount/vm_flags only if page is foundAndrea Arcangeli2011-03-13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm: use correct numa policy node for transparent hugepagesAndi Kleen2011-03-04
| | | | | | | | | | | | | | | | | | | | | 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>
* mm: preserve original node for transparent huge page copiesAndi Kleen2011-03-04
| | | | | | | | | | | | 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>
* mm: change alloc_pages_vma to pass down the policy node for local policyAndi Kleen2011-03-04
| | | | | | | | | | | | | 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>
* memcg: more mem_cgroup_uncharge() batchingHugh Dickins2011-02-25
| | | | | | | | | | | | | | 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>
* thp: fix interleaving for transparent hugepagesAndi Kleen2011-02-25
| | | | | | | | | | | 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>
* mm: fix dubious code in __count_immobile_pages()Namhyung Kim2011-02-25
| | | | | | | | | | | 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>
* mm: vmscan: stop reclaim/compaction earlier due to insufficient progress if ↵Mel Gorman2011-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | !__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>
* mm: grab rcu read lock in move_pages()Greg Thelen2011-02-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm: fix refcounting in swaponMiklos Szeredi2011-02-24
| | | | | | | | | | | | | | 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>
* mm: fix possible cause of a page_mapped BUGHugh Dickins2011-02-24
| | | | | | | | | | | | | | | | | | | | | 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>
* mm: prevent concurrent unmap_mapping_range() on the same inodeMiklos Szeredi2011-02-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* thp: prevent hugepages during args/env copying into the user stackAndrea Arcangeli2011-02-15
| | | | | | | | | | | | | 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>
* memcg: fix leak of accounting at failure path of hugepage collapsingKAMEZAWA Hiroyuki2011-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* vmscan: fix zone shrinking exit when scan work is doneJohannes Weiner2011-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mlock: do not munlock pages in __do_fault()Michel Lespinasse2011-02-11
| | | | | | | | | | | | | | | | | | 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>
* mlock: fix race when munlocking pages in do_wp_page()Michel Lespinasse2011-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* memblock: don't adjust size in memblock_find_base()Yinghai Lu2011-02-11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* memcg: fix event counting breakage from recent THP updateKAMEZAWA Hiroyuki2011-02-02
| | | | | | | | | | | | | | | | | 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>
* memcg: never OOM when charging huge pagesJohannes Weiner2011-02-02
| | | | | | | | | | | | | | | | 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>
* memcg: prevent endless loop when charging huge pages to near-limit groupJohannes Weiner2011-02-02
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* memcg: prevent endless loop when charging huge pagesJohannes Weiner2011-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* thp: fix unsuitable behavior for hwpoisoned tail pageJin Dongming2011-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* thp: fix the wrong reported address of hwpoisoned hugepagesJin Dongming2011-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* thp: fix splitting of hwpoisoned hugepagesJin Dongming2011-02-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm/migration: fix page corruption during hugepage migrationMinchan Kim2011-02-02
| | | | | | | | | | | | | | | | | | If migrate_huge_page by memory-failure fails , it calls put_page in itself to decrease page reference and caller of migrate_huge_page also calls putback_lru_pages. It can do double free of page so it can make page corruption on page holder. In addtion, clean of pages on caller is consistent behavior with migrate_pages by cf608ac19c ("mm: compaction: fix COMPACTPAGEFAILED counting"). Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Lameter <cl@linux.com> 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>
* mm: when migrate_pages returns 0, all pages must have been releasedAndrea Arcangeli2011-02-02
| | | | | | | | | | | | | | | | | | In some cases migrate_pages could return zero while still leaving a few pages in the pagelist (and some caller wouldn't notice it has to call putback_lru_pages after commit cf608ac19c9 ("mm: compaction: fix COMPACTPAGEFAILED counting")). Add one missing putback_lru_pages not added by commit cf608ac19c95 ("mm: compaction: fix COMPACTPAGEFAILED counting"). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Lameter <cl@linux.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* memsw: deprecate noswapaccount kernel parameter and schedule it for removalMichal Hocko2011-02-02
| | | | | | | | | | | | | | | noswapaccount couldn't be used to control memsw for both on/off cases so we have added swapaccount[=0|1] parameter. This way we can turn the feature in two ways noswapaccount resp. swapaccount=0. We have kept the original noswapaccount but I think we should remove it after some time as it just makes more command line parameters without any advantages and also the code to handle parameters is uglier if we want both parameters. Signed-off-by: Michal Hocko <mhocko@suse.cz> Requested-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
* memsw: handle swapaccount kernel parameter correctlyMichal Hocko2011-02-02
| | | | | | | | | | | | | | | | | | | | | | __setup based kernel command line parameters handlers which are handled in obsolete_checksetup are provided with the parameter value including = (more precisely everything right after the parameter name). This means that the current implementation of swapaccount[=1|0] doesn't work at all because if there is a value for the parameter then we are testing for "0" resp. "1" but we are getting "=0" resp. "=1" and if there is no parameter value we are getting an empty string rather than NULL. The original noswapccount parameter, which doesn't care about the value, works correctly. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mlock: operate on any regions with protection != PROT_NONEMichel Lespinasse2011-02-01
| | | | | | | | | | | | | | | | As Tao Ma noticed, change 5ecfda0 breaks blktrace. This is because blktrace mmaps a file with PROT_WRITE permissions but without PROT_READ, so my attempt to not unnecessarity break COW during mlock ended up causing mlock to fail with a permission problem. I am proposing to let mlock ignore vma protection in all cases except PROT_NONE. In particular, mlock should not fail for PROT_WRITE regions (as in the blktrace case, which broke at 5ecfda0) or for PROT_EXEC regions (which seem to me like they were always broken). Signed-off-by: Michel Lespinasse <walken@google.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-01-30
|\ | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm: kmemleak: Allow kmemleak metadata allocations to fail kmemleak: remove memset by using kzalloc
| * kmemleak: Allow kmemleak metadata allocations to failCatalin Marinas2011-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds __GFP_NORETRY and __GFP_NOMEMALLOC flags to the kmemleak metadata allocations so that it has a smaller effect on the users of the kernel slab allocator. Since kmemleak allocations can now fail more often, this patch also reduces the verbosity by passing __GFP_NOWARN and not dumping the stack trace when a kmemleak allocation fails. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Toralf Förster <toralf.foerster@gmx.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: David Rientjes <rientjes@google.com> Cc: Ted Ts'o <tytso@mit.edu>
| * kmemleak: remove memset by using kzallocJesper Juhl2011-01-27
| | | | | | | | | | | | | | | | | | We don't need to memset if we just use kzalloc() rather than kmalloc() in kmemleak_test_init(). Signed-off-by: Jesper Juhl <jj@chaosbits.net> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* | memcg: fix race at move_parent around compound_order()KAMEZAWA Hiroyuki2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A fix up mem_cgroup_move_parent() which use compound_order() in asynchronous manner. This compound_order() may return unknown value because we don't take lock. Use PageTransHuge() and HPAGE_SIZE instead of it. Also clean up for mem_cgroup_move_parent(). - remove unnecessary initialization of local variable. - rename charge_size -> page_size - remove unnecessary (wrong) comment. - added a comment about THP. Note: Current design take compound_page_lock() in caller of move_account(). This should be revisited when we implement direct move_task of hugepage without splitting. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: bugfix check mem_cgroup_disabled() at split fixupKAMEZAWA Hiroyuki2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_disabled() should be checked at splitting. If disabled, no heavy work is necesary. 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: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: fix account leak at failure of memsw accontingKAMEZAWA Hiroyuki2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 4b53433468 ("memcg: clean up try_charge main loop") removes a cancel of charge at case: memory charge-> success. mem+swap charge-> failure. This leaks usage of memory. Fix it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@in.ibm.com> Cc: <stable@kernel.org> [2.6.36+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: migration: clarify migrate_pages() commentMinchan Kim2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Callers of migrate_pages should putback_lru_pages to return pages isolated to LRU or free list. Now comment is rather confusing. It says caller always have to call it. It is more clear to point out that the caller has to call it if migrate_pages's return value isn't zero. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Lameter <cl@linux.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>
* | mm: compaction: don't depend on HUGETLB_PAGEAndrea Arcangeli2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 5d6892407 ("thp: select CONFIG_COMPACTION if TRANSPARENT_HUGEPAGE enabled") causes this warning during the configuration process: warning: (TRANSPARENT_HUGEPAGE) selects COMPACTION which has unmet direct dependencies (EXPERIMENTAL && HUGETLB_PAGE && MMU) COMPACTION doesn't depend on HUGETLB_PAGE, it doesn't depend on THP either, it is also useful for regular alloc_pages(order > 0) including the very kernel stack during fork (THREAD_ORDER = 1). It's always better to enable COMPACTION. The warning should be an error because we would end up with MIGRATION not selected, and COMPACTION wouldn't work without migration (despite it seems to build with an inline migrate_pages returning -ENOSYS). I'd also like to remove EXPERIMENTAL: compaction has been in the kernel for some releases (for full safety the default remains disabled which I think is enough). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Luca Tettamanti <kronos.it@gmail.com> Tested-by: Luca Tettamanti <kronos.it@gmail.com> 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>
* | mm/memcontrol.c: fix uninitialized variable use in mem_cgroup_move_parent()Jesper Juhl2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In mm/memcontrol.c::mem_cgroup_move_parent() there's a path that jumps to the 'put_back' label ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false, charge); if (ret || !parent) goto put_back; where we'll if (charge > PAGE_SIZE) compound_unlock_irqrestore(page, flags); but, we have not assigned anything to 'flags' at this point, nor have we called 'compound_lock_irqsave()' (which is what sets 'flags'). The 'put_back' label should be moved below the call to compound_unlock_irqrestore() as per this patch. Signed-off-by: Jesper Juhl <jj@chaosbits.net> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Pavel Emelianov <xemul@openvz.org> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocatorDavid Rientjes2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0e093d99763e ("writeback: do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone") uncovered a livelock in the page allocator that resulted in tasks infinitely looping trying to find memory and kswapd running at 100% cpu. The issue occurs because drain_all_pages() is called immediately following direct reclaim when no memory is freed and try_to_free_pages() returns non-zero because all zones in the zonelist do not have their all_unreclaimable flag set. When draining the per-cpu pagesets back to the buddy allocator for each zone, the zone->pages_scanned counter is cleared to avoid erroneously setting zone->all_unreclaimable later. The problem is that no pages may actually be drained and, thus, the unreclaimable logic never fails direct reclaim so the oom killer may be invoked. This apparently only manifested after wait_iff_congested() was introduced and the zone was full of anonymous memory that would not congest the backing store. The page allocator would infinitely loop if there were no other tasks waiting to be scheduled and clear zone->pages_scanned because of drain_all_pages() as the result of this change before kswapd could scan enough pages to trigger the reclaim logic. Additionally, with every loop of the page allocator and in the reclaim path, kswapd would be kicked and would end up running at 100% cpu. In this scenario, current and kswapd are all running continuously with kswapd incrementing zone->pages_scanned and current clearing it. The problem is even more pronounced when current swaps some of its memory to swap cache and the reclaimable logic then considers all active anonymous memory in the all_unreclaimable logic, which requires a much higher zone->pages_scanned value for try_to_free_pages() to return zero that is never attainable in this scenario. Before wait_iff_congested(), the page allocator would incur an unconditional timeout and allow kswapd to elevate zone->pages_scanned to a level that the oom killer would be called the next time it loops. The fix is to only attempt to drain pcp pages if there is actually a quantity to be drained. The unconditional clearing of zone->pages_scanned in free_pcppages_bulk() need not be changed since other callers already ensure that draining will occur. This patch ensures that free_pcppages_bulk() will actually free memory before calling into it from drain_all_pages() so zone->pages_scanned is only cleared if appropriate. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix deferred congestion timeout if preferred zone is not allowedDavid Rientjes2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before 0e093d99763e ("writeback: do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone"), preferred_zone was only used for NUMA statistics, to determine the zoneidx from which to allocate from given the type requested, and whether to utilize memory compaction. wait_iff_congested(), though, uses preferred_zone to determine if the congestion wait should be deferred because its dirty pages are backed by a congested bdi. This incorrectly defers the timeout and busy loops in the page allocator with various cond_resched() calls if preferred_zone is not allowed in the current context, usually consuming 100% of a cpu. This patch ensures preferred_zone is an allowed zone in the fastpath depending on whether current is constrained by its cpuset or nodes in its mempolicy (when the nodemask passed is non-NULL). This is correct since the fastpath allocation always passes ALLOC_CPUSET when trying to allocate memory. In the slowpath, this patch resets preferred_zone to the first zone of the allowed type when the allocation is not constrained by current's cpuset, i.e. it does not pass ALLOC_CPUSET. This patch also ensures preferred_zone is from the set of allowed nodes when called from within direct reclaim since allocations are always constrained by cpusets in this context (it is blockable). Both of these uses of cpuset_current_mems_allowed are protected by get_mems_allowed(). Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/pgtable-generic.c: fix CONFIG_SWAP=n buildAndrew Morton2011-01-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mips (and sparc32): In file included from arch/mips/include/asm/tlb.h:21, from mm/pgtable-generic.c:9: include/asm-generic/tlb.h: In function `tlb_flush_mmu': include/asm-generic/tlb.h:76: error: implicit declaration of function `release_pages' include/asm-generic/tlb.h: In function `tlb_remove_page': include/asm-generic/tlb.h:105: error: implicit declaration of function `page_cache_release' free_pages_and_swap_cache() and free_page_and_swap_cache() are macros which call release_pages() and page_cache_release(). The obvious fix is to include pagemap.h in swap.h, where those macros are defined. But that breaks sparc for weird reasons. So fix it within mm/pgtable-generic.c instead. Reported-by: Yoichi Yuasa <yuasa@linux-mips.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Cc: Sergei Shtylyov <sshtylyov@mvista.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: correctly order reading PCG_USED and pc->mem_cgroupJohannes Weiner2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | The placement of the read-side barrier is confused: the writer first sets pc->mem_cgroup, then PCG_USED. The read-side barrier has to be between testing PCG_USED and reading pc->mem_cgroup. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: fix truncate_setsize() commentJan Kara2011-01-20
| | | | | | | | | | | | | | | | | | | | | | Contrary to what the comment says, truncate_setsize() should be called *before* filesystem truncated blocks. Signed-off-by: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: fix rmdir, force_empty with THPKAMEZAWA Hiroyuki2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, when THP is enabled, memcg's rmdir() function is broken because move_account() for THP page is not supported. This will cause account leak or -EBUSY issue at rmdir(). This patch fixes the issue by supporting move_account() THP pages. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: fix LRU accounting with THPKAMEZAWA Hiroyuki2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | memory cgroup's LRU stat should take care of size of pages because Transparent Hugepage inserts hugepage into LRU. If this value is the number wrong, memory reclaim will not work well. Note: only head page of THP's huge page is linked into LRU. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: fix USED bit handling at uncharge in THPKAMEZAWA Hiroyuki2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now, under THP: at charge: - PageCgroupUsed bit is set to all page_cgroup on a hugepage. ....set to 512 pages. at uncharge - PageCgroupUsed bit is unset on the head page. So, some pages will remain with "Used" bit. This patch fixes that Used bit is set only to the head page. Used bits for tail pages will be set at splitting if necessary. This patch adds this lock order: compound_lock() -> page_cgroup_move_lock(). [akpm@linux-foundation.org: fix warning] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | memcg: modify accounting function for supporting THP betterKAMEZAWA Hiroyuki2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | mem_cgroup_charge_statisics() was designed for charging a page but now, we have transparent hugepage. To fix problems (in following patch) it's required to change the function to get the number of pages as its arguments. The new function gets following as argument. - type of page rather than 'pc' - size of page which is accounted. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: compaction: prevent division-by-zero during user-requested compactionJohannes Weiner2011-01-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Up until 3e7d344 ("mm: vmscan: reclaim order-0 and use compaction instead of lumpy reclaim"), compaction skipped calculating the fragmentation index of a zone when compaction was explicitely requested through the procfs knob. However, when compaction_suitable was introduced, it did not come with an extra check for order == -1, set on explicit compaction requests, and passed this order on to the fragmentation index calculation, where it overshifts the number of requested pages, leading to a division by zero. This patch makes sure that order == -1 is recognized as the flag it is rather than passing it along as valid order parameter. [akpm@linux-foundation.org: add comment, per Mel] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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