- 10 8月, 2010 40 次提交
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由 KOSAKI Motohiro 提交于
If a kernel thread is using use_mm(), badness() returns a positive value. This is not a big issue because caller take care of it correctly. But there is one exception, /proc/<pid>/oom_score calls badness() directly and doesn't care that the task is a regular process. Another example, /proc/1/oom_score return !0 value. But it's unkillable. This incorrectness makes administration a little confusing. This patch fixes it. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
When oom_kill_allocating_task is enabled, an argument task of oom_kill_process is not selected by select_bad_process(), It's just out_of_memory() caller task. It mean the task can be unkillable. check it first. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Presently we have the same task check in two places. Unify it. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Presently select_bad_process() has a PF_KTHREAD check, but oom_kill_process doesn't. It mean oom_kill_process() may choose wrong task, especially, when the child are using use_mm(). Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Presently, badness() doesn't care about either CPUSET nor mempolicy. Then if the victim child process have disjoint nodemask, OOM Killer might kill innocent process. This patch fixes it. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
When shrink_inactive_list() isolates pages, it updates a number of counters using temporary variables to gather them. These consume stack and it's in the main path that calls ->writepage(). This patch moves the accounting updates outside of the main path to reduce stack usage. Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
shrink_page_list() sets up a pagevec to release pages as according as they are free. It uses significant amounts of stack on the pagevec. This patch adds pages to be freed via pagevec to a linked list which is then freed en-masse at the end. This avoids using stack in the main path that potentially calls writepage(). Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
shrink_inactive_list() sets up a pagevec to release unfreeable pages. It uses significant amounts of stack doing this. This patch splits shrink_inactive_list() to take the stack usage out of the main path so that callers to writepage() do not contain an unused pagevec on the stack. Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Remove temporary variable that is only used once and does not help clarify code. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Now, max_scan of shrink_inactive_list() is always passed less than SWAP_CLUSTER_MAX. then, we can remove scanning pages loop in it. This patch also help stack diet. detail - remove "while (nr_scanned < max_scan)" loop - remove nr_freed (now, we use nr_reclaimed directly) - remove nr_scan (now, we use nr_scanned directly) - rename max_scan to nr_to_scan - pass nr_to_scan into isolate_pages() directly instead using SWAP_CLUSTER_MAX [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Since 2.6.28 zone->prev_priority is unused. Then it can be removed safely. It reduce stack usage slightly. Now I have to say that I'm sorry. 2 years ago, I thought prev_priority can be integrate again, it's useful. but four (or more) times trying haven't got good performance number. Thus I give up such approach. The rest of this changelog is notes on prev_priority and why it existed in the first place and why it might be not necessary any more. This information is based heavily on discussions between Andrew Morton, Rik van Riel and Kosaki Motohiro who is heavily quotes from. Historically prev_priority was important because it determined when the VM would start unmapping PTE pages. i.e. there are no balances of note within the VM, Anon vs File and Mapped vs Unmapped. Without prev_priority, there is a potential risk of unnecessarily increasing minor faults as a large amount of read activity of use-once pages could push mapped pages to the end of the LRU and get unmapped. There is no proof this is still a problem but currently it is not considered to be. Active files are not deactivated if the active file list is smaller than the inactive list reducing the liklihood that file-mapped pages are being pushed off the LRU and referenced executable pages are kept on the active list to avoid them getting pushed out by read activity. Even if it is a problem, prev_priority prev_priority wouldn't works nowadays. First of all, current vmscan still a lot of UP centric code. it expose some weakness on some dozens CPUs machine. I think we need more and more improvement. The problem is, current vmscan mix up per-system-pressure, per-zone-pressure and per-task-pressure a bit. example, prev_priority try to boost priority to other concurrent priority. but if the another task have mempolicy restriction, it is unnecessary, but also makes wrong big latency and exceeding reclaim. per-task based priority + prev_priority adjustment make the emulation of per-system pressure. but it have two issue 1) too rough and brutal emulation 2) we need per-zone pressure, not per-system. Another example, currently DEF_PRIORITY is 12. it mean the lru rotate about 2 cycle (1/4096 + 1/2048 + 1/1024 + .. + 1) before invoking OOM-Killer. but if 10,0000 thrreads enter DEF_PRIORITY reclaim at the same time, the system have higher memory pressure than priority==0 (1/4096*10,000 > 2). prev_priority can't solve such multithreads workload issue. In other word, prev_priority concept assume the sysmtem don't have lots threads." Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Add a trace event for when page reclaim queues a page for IO and records whether it is synchronous or asynchronous. Excessive synchronous IO for a process can result in noticeable stalls during direct reclaim. Excessive IO from page reclaim may indicate that the system is seriously under provisioned for the amount of dirty pages that exist. Signed-off-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NLarry Woodman <lwoodman@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Add an event for when pages are isolated en-masse from the LRU lists. This event augments the information available on LRU traffic and can be used to evaluate lumpy reclaim. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NLarry Woodman <lwoodman@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Mel Gorman 提交于
Add two trace events for kswapd waking up and going asleep for the purposes of tracking kswapd activity and two trace events for direct reclaim beginning and ending. The information can be used to work out how much time a process or the system is spending on the reclamation of pages and in the case of direct reclaim, how many pages were reclaimed for that process. High frequency triggering of these events could point to memory pressure problems. Signed-off-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NLarry Woodman <lwoodman@redhat.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Hellwig <hch@infradead.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Michael Rubin <mrubin@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
shrink_zones() need relatively long time and lru_pages can change dramatically during shrink_zones(). So lru_pages should be recalculated for each priority. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NRik van Riel <riel@redhat.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
Swap token don't works when zone reclaim is enabled since it was born. Because __zone_reclaim() always call disable_swap_token() unconditionally. This kill swap token feature completely. As far as I know, nobody want to that. Remove it. Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NRik van Riel <riel@redhat.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Jan Kara 提交于
We try to avoid livelocks of writeback when some steadily creates dirty pages in a mapping we are writing out. For memory-cleaning writeback, using nr_to_write works reasonably well but we cannot really use it for data integrity writeback. This patch tries to solve the problem. The idea is simple: Tag all pages that should be written back with a special tag (TOWRITE) in the radix tree. This can be done rather quickly and thus livelocks should not happen in practice. Then we start doing the hard work of locking pages and sending them to disk only for those pages that have TOWRITE tag set. Note: Adding new radix tree tag grows radix tree node from 288 to 296 bytes for 32-bit archs and from 552 to 560 bytes for 64-bit archs. However, the number of slab/slub items per page remains the same (13 and 7 respectively). Signed-off-by: NJan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Chris Mason <chris.mason@oracle.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Verify the refcounting doesn't go wrong, and resurrect the check in __page_check_anon_rmap as in old anon-vma code. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
With root anon-vma it's trivial to keep doing the usual check as in old-anon-vma code. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Always use anon_vma->root pointer instead of anon_vma_chain.prev. Also optimize the map-paths, if a mapping is already established no need to overwrite it with root anon-vma list, we can keep the more finegrined anon-vma and skip the overwrite: see the PageAnon check in !exclusive case. This is also the optimization that hidden the ksm bug as this tends to make ksm_might_need_to_copy skip the copy, but only the proper fix to ksm_might_need_to_copy guarantees not triggering the ksm bug unless ksm is in use. this is an optimization only... [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> [kamezawa.hiroyu@jp.fujitsu.com: fix false positive BUG_ON in __page_set_anon_rmap] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
Make sure to always add new VMAs at the end of the list. This is important so rmap_walk does not miss a VMA that was created during the rmap_walk. The old code got this right most of the time due to luck, but was buggy when anon_vma_prepare reused a mergeable anon_vma. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrea Arcangeli 提交于
There's no anon-vma related mangling happening inside __vma_link anymore so no need of anon_vma locking there. Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NRik van Riel <riel@redhat.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Shaohua Li 提交于
I'm running a shmem pagefault test case (see attached file) under a 64 CPU system. Profile shows shmem_inode_info->lock is heavily contented and 100% CPUs time are trying to get the lock. In the pagefault (no swap) case, shmem_getpage gets the lock twice, the last one is avoidable if we prealloc a page so we could reduce one time of locking. This is what below patch does. The result of the test case: 2.6.35-rc3: ~20s 2.6.35-rc3 + patch: ~12s so this is 40% improvement. One might argue if we could have better locking for shmem. But even shmem is lockless, the pagefault will soon have pagecache lock heavily contented because shmem must add new page to pagecache. So before we have better locking for pagecache, improving shmem locking doesn't have too much improvement. I did a similar pagefault test against a ramfs file, the test result is ~10.5s. [akpm@linux-foundation.org: fix comment, clean up code layout, elimintate code duplication] Signed-off-by: NShaohua Li <shaohua.li@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: "Zhang, Yanmin" <yanmin.zhang@intel.com> Cc: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Tim Chen 提交于
The current implementation of tmpfs is not scalable. We found that stat_lock is contended by multiple threads when we need to get a new page, leading to useless spinning inside this spin lock. This patch makes use of the percpu_counter library to maintain local count of used blocks to speed up getting and returning of pages. So the acquisition of stat_lock is unnecessary for getting and returning blocks, improving the performance of tmpfs on system with large number of cpus. On a 4 socket 32 core NHM-EX system, we saw improvement of 270%. The implementation below has a slight chance of race between threads causing a slight overshoot of the maximum configured blocks. However, any overshoot is small, and is bounded by the number of cpus. This happens when the number of used blocks is slightly below the maximum configured blocks when a thread checks the used block count, and another thread allocates the last block before the current thread does. This should not be a problem for tmpfs, as the overshoot is most likely to be a few blocks and bounded. If a strict limit is really desired, then configured the max blocks to be the limit less the number of cpus in system. Signed-off-by: NTim Chen <tim.c.chen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andi Kleen 提交于
No real bugs, just some dead code and some fixups. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 KOSAKI Motohiro 提交于
migrate_pages() is using >500 bytes stack. Reduce it. mm/mempolicy.c: In function 'sys_migrate_pages': mm/mempolicy.c:1344: warning: the frame size of 528 bytes is larger than 512 bytes [akpm@linux-foundation.org: don't play with a might-be-NULL pointer] Signed-off-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NChristoph Lameter <cl@linux-foundation.org> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Minchan Kim 提交于
The sum_vm_events passes cpumask for for_each_cpu(). But it's useless since we have for_each_online_cpu. Althougth it's tirival overhead, it's not good about coding consistency. Let's use for_each_online_cpu instead of for_each_cpu with cpumask argument. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NChristoph Lameter <cl@linux-foundation.org> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
__out_of_memory() only has a single caller, so fold it into out_of_memory() and add a comment about locking for its call to oom_kill_process(). Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
select_bad_process() and __out_of_memory() doe not need their enum oom_constraint arguments: it's possible to pass a NULL nodemask if constraint == CONSTRAINT_MEMORY_POLICY in the caller, out_of_memory(). Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Minchan Kim 提交于
We have been used naming try_set_zone_oom and clear_zonelist_oom. The role of functions is to lock of zonelist for preventing parallel OOM. So clear_zonelist_oom makes sense but try_set_zone_oome is rather awkward and unmatched with clear_zonelist_oom. Let's change it with try_set_zonelist_oom. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
Remove the redundancy in __oom_kill_task() since: - init can never be passed to this function: it will never be PF_EXITING or selectable from select_bad_process(), and - it will never be passed a task from oom_kill_task() without an ->mm and we're unconcerned about detachment from exiting tasks, there's no reason to protect them against SIGKILL or access to memory reserves. Also moves the kernel log message to a higher level since the verbosity is not always emitted here; we need not print an error message if an exiting task is given a longer timeslice. __oom_kill_task() only has a single caller, so it can be merged into that function at the same time. Signed-off-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
It is possible to remove the special pagefault oom handler by simply oom locking all system zones and then calling directly into out_of_memory(). All populated zones must have ZONE_OOM_LOCKED set, otherwise there is a parallel oom killing in progress that will lead to eventual memory freeing so it's not necessary to needlessly kill another task. The context in which the pagefault is allocating memory is unknown to the oom killer, so this is done on a system-wide level. If a task has already been oom killed and hasn't fully exited yet, this will be a no-op since select_bad_process() recognizes tasks across the system with TIF_MEMDIE set. Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NNick Piggin <npiggin@suse.de> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
There are various points in the oom killer where the kernel must determine whether to panic or not. It's better to extract this to a helper function to remove all the confusion as to its semantics. Also fix a call to dump_header() where tasklist_lock is not read- locked, as required. There's no functional change with this patch. Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
If memory has been depleted in lowmem zones even with the protection afforded to it by /proc/sys/vm/lowmem_reserve_ratio, it is unlikely that killing current users will help. The memory is either reclaimable (or migratable) already, in which case we should not invoke the oom killer at all, or it is pinned by an application for I/O. Killing such an application may leave the hardware in an unspecified state and there is no guarantee that it will be able to make a timely exit. Lowmem allocations are now failed in oom conditions when __GFP_NOFAIL is not used so that the task can perhaps recover or try again later. Previously, the heuristic provided some protection for those tasks with CAP_SYS_RAWIO, but this is no longer necessary since we will not be killing tasks for the purposes of ISA allocations. high_zoneidx is gfp_zone(gfp_flags), meaning that ZONE_NORMAL will be the default for all allocations that are not __GFP_DMA, __GFP_DMA32, __GFP_HIGHMEM, and __GFP_MOVABLE on kernels configured to support those flags. Testing for high_zoneidx being less than ZONE_NORMAL will only return true for allocations that have either __GFP_DMA or __GFP_DMA32. Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
The oom killer tasklist dump, enabled with the oom_dump_tasks sysctl, is very helpful information in diagnosing why a user's task has been killed. It emits useful information such as each eligible thread's memory usage that can determine why the system is oom, so it should be enabled by default. Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
The oom killer presently kills current whenever there is no more memory free or reclaimable on its mempolicy's nodes. There is no guarantee that current is a memory-hogging task or that killing it will free any substantial amount of memory, however. In such situations, it is better to scan the tasklist for nodes that are allowed to allocate on current's set of nodes and kill the task with the highest badness() score. This ensures that the most memory-hogging task, or the one configured by the user with /proc/pid/oom_adj, is always selected in such scenarios. Signed-off-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
When a task is chosen for oom kill, the oom killer first attempts to sacrifice a child not sharing its parent's memory instead. Unfortunately, this often kills in a seemingly random fashion based on the ordering of the selected task's child list. Additionally, it is not guaranteed at all to free a large amount of memory that we need to prevent additional oom killing in the very near future. Instead, we now only attempt to sacrifice the worst child not sharing its parent's memory, if one exists. The worst child is indicated with the highest badness() score. This serves two advantages: we kill a memory-hogging task more often, and we allow the configurable /proc/pid/oom_adj value to be considered as a factor in which child to kill. Reviewers may observe that the previous implementation would iterate through the children and attempt to kill each until one was successful and then the parent if none were found while the new code simply kills the most memory-hogging task or the parent. Note that the only time oom_kill_task() fails, however, is when a child does not have an mm or has a /proc/pid/oom_adj of OOM_DISABLE. badness() returns 0 for both cases, so the final oom_kill_task() will always succeed. Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NNick Piggin <npiggin@suse.de> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
Tasks that do not share the same set of allowed nodes with the task that triggered the oom should not be considered as candidates for oom kill. Tasks in other cpusets with a disjoint set of mems would be unfairly penalized otherwise because of oom conditions elsewhere; an extreme example could unfairly kill all other applications on the system if a single task in a user's cpuset sets itself to OOM_DISABLE and then uses more memory than allowed. Killing tasks outside of current's cpuset rarely would free memory for current anyway. To use a sane heuristic, we must ensure that killing a task would likely free memory for current and avoid needlessly killing others at all costs just because their potential memory freeing is unknown. It is better to kill current than another task needlessly. Signed-off-by: NDavid Rientjes <rientjes@google.com> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NNick Piggin <npiggin@suse.de> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
It's unnecessary to SIGKILL a task that is already PF_EXITING and can actually cause a NULL pointer dereference of the sighand if it has already been detached. Instead, simply set TIF_MEMDIE so it has access to memory reserves and can quickly exit as the comment implies. Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 David Rientjes 提交于
It's possible to livelock the page allocator if a thread has mm->mmap_sem and fails to make forward progress because the oom killer selects another thread sharing the same ->mm to kill that cannot exit until the semaphore is dropped. The oom killer will not kill multiple tasks at the same time; each oom killed task must exit before another task may be killed. Thus, if one thread is holding mm->mmap_sem and cannot allocate memory, all threads sharing the same ->mm are blocked from exiting as well. In the oom kill case, that means the thread holding mm->mmap_sem will never free additional memory since it cannot get access to memory reserves and the thread that depends on it with access to memory reserves cannot exit because it cannot acquire the semaphore. Thus, the page allocators livelocks. When the oom killer is called and current happens to have a pending SIGKILL, this patch automatically gives it access to memory reserves and returns. Upon returning to the page allocator, its allocation will hopefully succeed so it can quickly exit and free its memory. If not, the page allocator will fail the allocation if it is not __GFP_NOFAIL. Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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