- 23 3月, 2011 29 次提交
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由 Dave Hansen 提交于
Right now, if a mm_walk has either ->pte_entry or ->pmd_entry set, it will unconditionally split any transparent huge pages it runs in to. In practice, that means that anyone doing a cat /proc/$pid/smaps will unconditionally break down every huge page in the process and depend on khugepaged to re-collapse it later. This is fairly suboptimal. This patch changes that behavior. It teaches each ->pmd_entry handler (there are five) that they must break down the THPs themselves. Also, the _generic_ code will never break down a THP unless a ->pte_entry handler is actually set. This means that the ->pmd_entry handlers can now choose to deal with THPs without breaking them down. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: NDave Hansen <dave@linux.vnet.ibm.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-by: NDavid Rientjes <rientjes@google.com> Reviewed-by: NEric B Munson <emunson@mgebm.net> Tested-by: NEric B Munson <emunson@mgebm.net> Cc: Michael J Wolf <mjwolf@us.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Jeremy Fitzhardinge <jeremy@goop.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
invalidate_mapping_pages is very big hint to reclaimer. It means user doesn't want to use the page any more. So in order to prevent working set page eviction, this patch move the page into tail of inactive list by PG_reclaim. Please, remember that pages in inactive list are working set as well as active list. If we don't move pages into inactive list's tail, pages near by tail of inactive list can be evicted although we have a big clue about useless pages. It's totally bad. Now PG_readahead/PG_reclaim is shared. fe3cba17 added ClearPageReclaim into clear_page_dirty_for_io for preventing fast reclaiming readahead marker page. In this series, PG_reclaim is used by invalidated page, too. If VM find the page is invalidated and it's dirty, it sets PG_reclaim to reclaim asap. Then, when the dirty page will be writeback, clear_page_dirty_for_io will clear PG_reclaim unconditionally. It disturbs this serie's goal. I think it's okay to clear PG_readahead when the page is dirty, not writeback time. So this patch moves ClearPageReadahead. In v4, ClearPageReadahead in set_page_dirty has a problem which is reported by Steven Barrett. It's due to compound page. Some driver(ex, audio) calls set_page_dirty with compound page which isn't on LRU. but my patch does ClearPageRelcaim on compound page. In non-CONFIG_PAGEFLAGS_EXTENDED, it breaks PageTail flag. I think it doesn't affect THP and pass my test with THP enabling but Cced Andrea for double check. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Reported-by: NSteven Barrett <damentz@liquorix.net> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Andrea Arcangeli <aarcange@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 Minchan Kim 提交于
The rotate_reclaimable_page function moves just written out pages, which the VM wanted to reclaim, to the end of the inactive list. That way the VM will find those pages first next time it needs to free memory. This patch applies the rule in memcg. It can help to prevent unnecessary working page eviction of memcg. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NBalbir Singh <balbir@linux.vnet.ibm.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NRik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@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 Minchan Kim 提交于
Recently, there are reported problem about thrashing. (http://marc.info/?l=rsync&m=128885034930933&w=2) It happens by backup workloads(ex, nightly rsync). That's because the workload makes just use-once pages and touches pages twice. It promotes the page into active list so that it results in working set page eviction. Some app developer want to support POSIX_FADV_NOREUSE. But other OSes don't support it, either. (http://marc.info/?l=linux-mm&m=128928979512086&w=2) By other approach, app developers use POSIX_FADV_DONTNEED. But it has a problem. If kernel meets page is writing during invalidate_mapping_pages, it can't work. It makes for application programmer to use it since they always have to sync data before calling fadivse(..POSIX_FADV_DONTNEED) to make sure the pages could be discardable. At last, they can't use deferred write of kernel so that they could see performance loss. (http://insights.oetiker.ch/linux/fadvise.html) In fact, invalidation is very big hint to reclaimer. It means we don't use the page any more. So let's move the writing page into inactive list's head if we can't truncate it right now. Why I move page to head of lru on this patch, Dirty/Writeback page would be flushed sooner or later. It can prevent writeout of pageout which is less effective than flusher's writeout. Originally, I reused lru_demote of Peter with some change so added his Signed-off-by. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Reported-by: NBen Gamari <bgamari.foss@gmail.com> Signed-off-by: NPeter Zijlstra <peterz@infradead.org> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Andrea Arcangeli <aarcange@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 Peter Zijlstra 提交于
This patch changes the anon_vma refcount to be 0 when the object is free. It does this by adding 1 ref to being in use in the anon_vma structure (iow. the anon_vma->head list is not empty). This allows a simpler release scheme without having to check both the refcount and the list as well as avoids taking a ref for each entry on the list. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Acked-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 Peter Zijlstra 提交于
We need the anon_vma refcount unconditionally to simplify the anon_vma lifetime rules. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NHugh Dickins <hughd@google.com> Acked-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 Peter Zijlstra 提交于
The normal code pattern used in the kernel is: get/put. Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: NHugh Dickins <hughd@google.com> Reviewed-by: NRik van Riel <riel@redhat.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Akinobu Mita 提交于
Fix kconfig dependency warning to satisfy dependencies: warning: (PAGE_POISONING) selects DEBUG_PAGEALLOC which has unmet direct dependencies (DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC && (!HIBERNATION || !PPC && !SPARC) && !KMEMCHECK) Signed-off-by: NAkinobu Mita <akinobu.mita@gmail.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Namhyung Kim 提交于
free_pcppages_bulk() frees pages from pcp lists in a round-robin fashion by keeping batch_free counter. But it doesn't need to spin if there is only one non-empty list. This can be checked by batch_free == MIGRATE_PCPTYPES. [akpm@linux-foundation.org: fix comment] Signed-off-by: NNamhyung Kim <namhyung@gmail.com> Acked-by: NJohannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> 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
Now we renamed remove_from_page_cache with delete_from_page_cache. As consistency of __remove_from_swap_cache and remove_from_swap_cache, we change internal page cache handling function name, too. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.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 Minchan Kim 提交于
Now delete_from_page_cache() replaces remove_from_page_cache(). So we remove remove_from_page_cache so fs or something out of mainline will notice it when compile time and can fix it. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.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 Minchan Kim 提交于
This patch series changes remove_from_page_cache()'s page ref counting rule. Page cache ref count is decreased in delete_from_page_cache(). So we don't need to decrease the page reference in callers. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.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 Minchan Kim 提交于
This patch series changes remove_from_page_cache()'s page ref counting rule. Page cache ref count is decreased in delete_from_page_cache(). So we don't need to decrease the page reference in callers. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.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 Minchan Kim 提交于
Presently we increase the page refcount in add_to_page_cache() but don't decrease it in remove_from_page_cache(). Such asymmetry adds confusion, requiring that callers notice it and a comment explaining why they release a page reference. It's not a good API. A long time ago, Hugh tried it (http://lkml.org/lkml/2004/10/24/140) but gave up because reiser4's drop_page() had to unlock the page between removing it from page cache and doing the page_cache_release(). But now the situation is changed. I think at least things in current mainline don't have any obstacles. The problem is for out-of-mainline filesystems - if they have done such things as reiser4, this patch could be a problem but they will discover this at compile time since we remove remove_from_page_cache(). This patch: This function works as just wrapper remove_from_page_cache(). The difference is that it decreases page references in itself. So caller have to make sure it has a page reference before calling. This patch is ready for removing remove_from_page_cache(). Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Acked-by: NHugh Dickins <hughd@google.com> Acked-by: NMel Gorman <mel@csn.ul.ie> Reviewed-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: NKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Edward Shishkin <edward.shishkin@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Miklos Szeredi 提交于
This function basically does: remove_from_page_cache(old); page_cache_release(old); add_to_page_cache_locked(new); Except it does this atomically, so there's no possibility for the "add" to fail because of a race. If memory cgroups are enabled, then the memory cgroup charge is also moved from the old page to the new. This function is currently used by fuse to move pages into the page cache on read, instead of copying the page contents. [minchan.kim@gmail.com: add freepage() hook to replace_page_cache_page()] Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz> Acked-by: NRik van Riel <riel@redhat.com> Acked-by: NKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Gleb Natapov 提交于
GUP user may want to try to acquire a reference to a page if it is already in memory, but not if IO, to bring it in, is needed. For example KVM may tell vcpu to schedule another guest process if current one is trying to access swapped out page. Meanwhile, the page will be swapped in and the guest process, that depends on it, will be able to run again. This patch adds FAULT_FLAG_RETRY_NOWAIT (suggested by Linus) and FOLL_NOWAIT follow_page flags. FAULT_FLAG_RETRY_NOWAIT, when used in conjunction with VM_FAULT_ALLOW_RETRY, indicates to handle_mm_fault that it shouldn't drop mmap_sem and wait on a page, but return VM_FAULT_RETRY instead. [akpm@linux-foundation.org: improve FOLL_NOWAIT comment] Signed-off-by: NGleb Natapov <gleb@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Acked-by: NRik van Riel <riel@redhat.com> Cc: Michel Lespinasse <walken@google.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@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 Prarit Bhargava 提交于
While looking at some other notifier callbacks I noticed this code could use a simple cleanup. notifier_from_errno() no longer needs the if (ret)/else conditional. That same conditional is now done in notifier_from_errno(). Signed-off-by: NPrarit Bhargava <prarit@redhat.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Acked-by: NPekka Enberg <penberg@cs.helsinki.fi> 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
Displaying extremely verbose meminfo for all nodes on the system is overkill for page allocation failures when the context restricts that allocation to only a subset of nodes. We don't particularly care about the state of all nodes when some are not allowed in the current context, they can have an abundance of memory but we can't allocate from that part of memory. This patch suppresses disallowed nodes from the meminfo dump on a page allocation failure if the context requires it. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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
When a page allocation failure occurs, show_mem() is called to dump the state of the VM so users may understand what happened to get into that condition. This output, however, can be extremely verbose. In irq context, it may result in significant delays that incur NMI watchdog timeouts when the machine is large (we use CONFIG_NODES_SHIFT > 8 here to define a "large" machine since the length of the show_mem() output is proportional to the number of possible nodes). This patch suppresses the show_mem() call in irq context when the kernel has CONFIG_NODES_SHIFT > 8. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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
The oom killer is extremely verbose for machines with a large number of cpus and/or nodes. This verbosity can often be harmful if it causes other important messages to be scrolled from the kernel log and incurs a signicant time delay, specifically for kernels with CONFIG_NODES_SHIFT > 8. This patch causes only memory information to be displayed for nodes that are allowed by current's cpuset when dumping the VM state. Information for all other nodes is irrelevant to the oom condition; we don't care if there's an abundance of memory elsewhere if we can't access it. This only affects the behavior of dumping memory information when an oom is triggered. Other dumps, such as for sysrq+m, still display the unfiltered form when using the existing show_mem() interface. Additionally, the per-cpu pageset statistics are extremely verbose in oom killer output, so it is now suppressed. This removes nodes_weight(current->mems_allowed) * (1 + nr_cpus) lines from the oom killer output. Callers may use __show_mem(SHOW_MEM_FILTER_NODES) to filter disallowed nodes. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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 Minchan Kim 提交于
Many migrate_page's caller check return value instead of list_empy by cf608ac1 ("mm: compaction: fix COMPACTPAGEFAILED counting"). This patch makes compaction's migrate_pages consistent with others. This patch should not change old behavior. Signed-off-by: NMinchan Kim <minchan.kim@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoph Lameter <cl@linux.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
This patch reverts 5a03b051 ("thp: use compaction in kswapd for GFP_ATOMIC order > 0") due to reports stating that kswapd CPU usage was higher and IRQs were being disabled more frequently. This was reported at http://www.spinics.net/linux/fedora/alsa-user/msg09885.html. Without this patch applied, CPU usage by kswapd hovers around the 20% mark according to the tester (Arthur Marsh: http://www.spinics.net/linux/fedora/alsa-user/msg09899.html). With this patch applied, it's around 2%. The problem is not related to THP which specifies __GFP_NO_KSWAPD but is triggered by high-order allocations hitting the low watermark for their order and waking kswapd on kernels with CONFIG_COMPACTION set. The most common trigger for this is network cards configured for jumbo frames but it's also possible it'll be triggered by fork-heavy workloads (order-1) and some wireless cards which depend on order-1 allocations. The symptoms for the user will be high CPU usage by kswapd in low-memory situations which could be confused with another writeback problem. While a patch like 5a03b051 may be reintroduced in the future, this patch plays it safe for now and reverts it. [mel@csn.ul.ie: Beefed up the changelog] Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Signed-off-by: NMel Gorman <mel@csn.ul.ie> Reported-by: NArthur Marsh <arthur.marsh@internode.on.net> Tested-by: NArthur Marsh <arthur.marsh@internode.on.net> Cc: <stable@kernel.org> [2.6.38.1] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Nick Piggin 提交于
Provide a free area cache for the vmalloc virtual address allocator, based on the algorithm used by the user virtual memory allocator. This reduces the number of rbtree operations and linear traversals over the vmap extents in order to find a free area, by starting off at the last point that a free area was found. The free area cache is reset if areas are freed behind it, or if we are searching for a smaller area or alignment than last time. So allocation patterns are not changed (verified by corner-case and random test cases in userspace testing). This solves a regression caused by lazy vunmap TLB purging introduced in db64fe02 (mm: rewrite vmap layer). That patch will leave extents in the vmap allocator after they are vunmapped, and until a significant number accumulate that can be flushed in a single batch. So in a workload that vmalloc/vfree frequently, a chain of extents will build up from VMALLOC_START address, which have to be iterated over each time (giving an O(n) type of behaviour). After this patch, the search will start from where it left off, giving closer to an amortized O(1). This is verified to solve regressions reported Steven in GFS2, and Avi in KVM. Hugh's update: : I tried out the recent mmotm, and on one machine was fortunate to hit : the BUG_ON(first->va_start < addr) which seems to have been stalling : your vmap area cache patch ever since May. : I can get you addresses etc, I did dump a few out; but once I stared : at them, it was easier just to look at the code: and I cannot see how : you would be so sure that first->va_start < addr, once you've done : that addr = ALIGN(max(...), align) above, if align is over 0x1000 : (align was 0x8000 or 0x4000 in the cases I hit: ioremaps like Steve). : I originally got around it by just changing the : if (first->va_start < addr) { : to : while (first->va_start < addr) { : without thinking about it any further; but that seemed unsatisfactory, : why would we want to loop here when we've got another very similar : loop just below it? : I am never going to admit how long I've spent trying to grasp your : "while (n)" rbtree loop just above this, the one with the peculiar : if (!first && tmp->va_start < addr + size) : in. That's unfamiliar to me, I'm guessing it's designed to save a : subsequent rb_next() in a few circumstances (at risk of then setting : a wrong cached_hole_size?); but they did appear few to me, and I didn't : feel I could sign off something with that in when I don't grasp it, : and it seems responsible for extra code and mistaken BUG_ON below it. : I've reverted to the familiar rbtree loop that find_vma() does (but : with va_end >= addr as you had, to respect the additional guard page): : and then (given that cached_hole_size starts out 0) I don't see the : need for any complications below it. If you do want to keep that loop : as you had it, please add a comment to explain what it's trying to do, : and where addr is relative to first when you emerge from it. : Aren't your tests "size <= cached_hole_size" and : "addr + size > first->va_start" forgetting the guard page we want : before the next area? I've changed those. : I have not changed your many "addr + size - 1 < addr" overflow tests, : but have since come to wonder, shouldn't they be "addr + size < addr" : tests - won't the vend checks go wrong if addr + size is 0? : I have added a few comments - Wolfgang Wander's 2.6.13 description of : 1363c3cd Avoiding mmap fragmentation : helped me a lot, perhaps a pointer to that would be good too. And I found : it easier to understand when I renamed cached_start slightly and moved the : overflow label down. : This patch would go after your mm-vmap-area-cache.patch in mmotm. : Trivially, nobody is going to get that BUG_ON with this patch, and it : appears to work fine on my machines; but I have not given it anything like : the testing you did on your original, and may have broken all the : performance you were aiming for. Please take a look and test it out : integrate with yours if you're satisfied - thanks. [akpm@linux-foundation.org: add locking comment] Signed-off-by: NNick Piggin <npiggin@suse.de> Signed-off-by: NHugh Dickins <hughd@google.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Reported-and-tested-by: NSteven Whitehouse <swhiteho@redhat.com> Reported-and-tested-by: NAvi Kivity <avi@redhat.com> Tested-by: N"Barry J. Marson" <bmarson@redhat.com> Cc: Prarit Bhargava <prarit@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 David Rientjes 提交于
The oom killer naturally defers killing anything if it finds an eligible task that is already exiting and has yet to detach its ->mm. This avoids unnecessarily killing tasks when one is already in the exit path and may free enough memory that the oom killer is no longer needed. This is detected by PF_EXITING since threads that have already detached its ->mm are no longer considered at all. The problem with always deferring when a thread is PF_EXITING, however, is that it may never actually exit when being traced, specifically if another task is tracing it with PTRACE_O_TRACEEXIT. The oom killer does not want to defer in this case since there is no guarantee that thread will ever exit without intervention. This patch will now only defer the oom killer when a thread is PF_EXITING and no ptracer has stopped its progress in the exit path. It also ensures that a child is sacrificed for the chosen parent only if it has a different ->mm as the comment implies: this ensures that the thread group leader is always targeted appropriately. Signed-off-by: NDavid Rientjes <rientjes@google.com> Reported-by: NOleg Nesterov <oleg@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Andrey Vagin 提交于
We shouldn't defer oom killing if a thread has already detached its ->mm and still has TIF_MEMDIE set. Memory needs to be freed, so find kill other threads that pin the same ->mm or find another task to kill. Signed-off-by: NAndrey Vagin <avagin@openvz.org> Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> [2.6.38.x] 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
This patch prevents unnecessary oom kills or kernel panics by reverting two commits: 495789a5 (oom: make oom_score to per-process value) cef1d352 (oom: multi threaded process coredump don't make deadlock) First, 495789a5 (oom: make oom_score to per-process value) ignores the fact that all threads in a thread group do not necessarily exit at the same time. It is imperative that select_bad_process() detect threads that are in the exit path, specifically those with PF_EXITING set, to prevent needlessly killing additional tasks. If a process is oom killed and the thread group leader exits, select_bad_process() cannot detect the other threads that are PF_EXITING by iterating over only processes. Thus, it currently chooses another task unnecessarily for oom kill or panics the machine when nothing else is eligible. By iterating over threads instead, it is possible to detect threads that are exiting and nominate them for oom kill so they get access to memory reserves. Second, cef1d352 (oom: multi threaded process coredump don't make deadlock) erroneously avoids making the oom killer a no-op when an eligible thread other than current isfound to be exiting. We want to detect this situation so that we may allow that exiting thread time to exit and free its memory; if it is able to exit on its own, that should free memory so current is no loner oom. If it is not able to exit on its own, the oom killer will nominate it for oom kill which, in this case, only means it will get access to memory reserves. Without this change, it is easy for the oom killer to unnecessarily target tasks when all threads of a victim don't exit before the thread group leader or, in the worst case, panic the machine. Signed-off-by: NDavid Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrey Vagin <avagin@openvz.org> Cc: <stable@kernel.org> [2.6.38.x] 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
If an administrator tries to swapon a file backed by NFS, the inode mutex is taken (as it is for any swapfile) but later identified to be a bad swapfile due to the lack of bmap and tries to cleanup. During cleanup, an attempt is made to close the file but with inode->i_mutex still held. Closing an NFS file syncs it which tries to acquire the inode mutex leading to deadlock. If lockdep is enabled the following appears on the console; ============================================= [ INFO: possible recursive locking detected ] 2.6.38-rc8-autobuild #1 --------------------------------------------- swapon/2192 is trying to acquire lock: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: vfs_fsync_range+0x47/0x7c but task is already holding lock: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7 other info that might help us debug this: 1 lock held by swapon/2192: #0: (&sb->s_type->i_mutex_key#13){+.+.+.}, at: sys_swapon+0x28d/0xae7 stack backtrace: Pid: 2192, comm: swapon Not tainted 2.6.38-rc8-autobuild #1 Call Trace: __lock_acquire+0x2eb/0x1623 find_get_pages_tag+0x14a/0x174 pagevec_lookup_tag+0x25/0x2e vfs_fsync_range+0x47/0x7c lock_acquire+0xd3/0x100 vfs_fsync_range+0x47/0x7c nfs_flush_one+0x0/0xdf [nfs] mutex_lock_nested+0x40/0x2b1 vfs_fsync_range+0x47/0x7c vfs_fsync_range+0x47/0x7c vfs_fsync+0x1c/0x1e nfs_file_flush+0x64/0x69 [nfs] filp_close+0x43/0x72 sys_swapon+0xa39/0xae7 sysret_check+0x2e/0x69 system_call_fastpath+0x16/0x1b This patch releases the mutex if its held before calling filep_close() so swapon fails as expected without deadlock when the swapfile is backed by NFS. If accepted for 2.6.39, it should also be considered a -stable candidate for 2.6.38 and 2.6.37. Signed-off-by: NMel Gorman <mgorman@suse.de> Acked-by: NHugh Dickins <hughd@google.com> Cc: <stable@kernel.org> [2.6.37+] Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Christoph Lameter 提交于
Add some statistics for debugging. Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NPekka Enberg <penberg@kernel.org>
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由 Christoph Lameter 提交于
OOM path is missing the irq restore in the CONFIG_CMPXCHG_LOCAL case. Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NPekka Enberg <penberg@kernel.org>
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- 21 3月, 2011 1 次提交
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由 Christoph Lameter 提交于
The redo label needs #ifdeffery. Fixes the following problem introduced by commit 8a5ec0ba ("Lockless (and preemptless) fastpaths for slub"): mm/slub.c: In function 'slab_free': mm/slub.c:2124: warning: label 'redo' defined but not used Reported-by: NStephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NPekka Enberg <penberg@kernel.org>
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- 18 3月, 2011 4 次提交
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由 Andrea Arcangeli 提交于
Change the _mapcount value indicating PageBuddy from -2 to -128 for more robusteness against page_mapcount() undeflows. Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to ignore the previous retval of PageBuddy(). Signed-off-by: NAndrea Arcangeli <aarcange@redhat.com> Reported-by: NHugh Dickins <hughd@google.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Huang Ying 提交于
Unused. Signed-off-by: NHuang Ying <ying.huang@intel.com> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
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由 Huang Ying 提交于
Make __get_user_pages return -EHWPOISON for HWPOISON page only if FOLL_HWPOISON is specified. With this patch, the interested callers can distinguish HWPOISON pages from general FAULT pages, while other callers will still get -EFAULT for all these pages, so the user space interface need not to be changed. This feature is needed by KVM, where UCR MCE should be relayed to guest for HWPOISON page, while instruction emulation and MMIO will be tried for general FAULT page. The idea comes from Andrew Morton. Signed-off-by: NHuang Ying <ying.huang@intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com> Signed-off-by: NAvi Kivity <avi@redhat.com>
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由 Huang Ying 提交于
In most cases, get_user_pages and get_user_pages_fast should be used to pin user pages in memory. But sometimes, some special flags except FOLL_GET, FOLL_WRITE and FOLL_FORCE are needed, for example in following patch, KVM needs FOLL_HWPOISON. To support these users, __get_user_pages is exported directly. There are some symbol name conflicts in infiniband driver, fixed them too. Signed-off-by: NHuang Ying <ying.huang@intel.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Michel Lespinasse <walken@google.com> CC: Roland Dreier <roland@kernel.org> CC: Ralph Campbell <infinipath@qlogic.com> Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>
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- 15 3月, 2011 2 次提交
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由 Linus Torvalds 提交于
This reverts the parent commit. I hate doing that, but it's generating some discussion ("half of it is right"), and since I am planning on doing the 2.6.38 release later today we can punt it to stable if required. Let's not rock the boat right now. Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Oleg Nesterov 提交于
oom_kill_process() starts with victim_points == 0. This means that (most likely) any child has more points and can be killed erroneously. Also, "children has a different mm" doesn't match the reality, we should check child->mm != t->mm. This check is not exactly correct if t->mm == NULL but this doesn't really matter, oom_kill_task() will kill them anyway. Note: "Kill all processes sharing p->mm" in oom_kill_task() is wrong too. Signed-off-by: NOleg Nesterov <oleg@redhat.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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- 14 3月, 2011 3 次提交
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由 Hugh Dickins 提交于
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: NHugh Dickins <hughd@google.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
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由 Aneesh Kumar K.V 提交于
The exportfs encode handle function should return the minimum required handle size. This helps user to find out the handle size by passing 0 handle size in the first step and then redoing to the call again with the returned handle size value. Acked-by: NSerge Hallyn <serue@us.ibm.com> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
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由 Andrea Arcangeli 提交于
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: NAndrea Arcangeli <aarcange@redhat.com> Reported-by: NMichel Lespinasse <walken@google.com> Reviewed-by: NMichel Lespinasse <walken@google.com> Reviewed-by: NMinchan Kim <minchan.kim@gmail.com> Reviewed-by: NJohannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel<riel@redhat.com> 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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- 12 3月, 2011 1 次提交
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由 Lai Jiangshan 提交于
The size of struct rcu_head may be changed. When it becomes larger, it may pollute the data after struct slab. Acked-by: NChristoph Lameter <cl@linux.com> Signed-off-by: NLai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: NPekka Enberg <penberg@kernel.org>
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