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2010-05-25mm: compaction: add a tunable that decides when memory should be compacted ↵Mel Gorman
and when it should be reclaimed The kernel applies some heuristics when deciding if memory should be compacted or reclaimed to satisfy a high-order allocation. One of these is based on the fragmentation. If the index is below 500, memory will not be compacted. This choice is arbitrary and not based on data. To help optimise the system and set a sensible default for this value, this patch adds a sysctl extfrag_threshold. The kernel will only compact memory if the fragmentation index is above the extfrag_threshold. [randy.dunlap@oracle.com: Fix build errors when proc fs is not configured] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: 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>
2010-05-25mm: compaction: direct compact when a high-order allocation failsMel Gorman
Ordinarily when a high-order allocation fails, direct reclaim is entered to free pages to satisfy the allocation. With this patch, it is determined if an allocation failed due to external fragmentation instead of low memory and if so, the calling process will compact until a suitable page is freed. Compaction by moving pages in memory is considerably cheaper than paging out to disk and works where there are locked pages or no swap. If compaction fails to free a page of a suitable size, then reclaim will still occur. Direct compaction returns as soon as possible. As each block is compacted, it is checked if a suitable page has been freed and if so, it returns. [akpm@linux-foundation.org: Fix build errors] [aarcange@redhat.com: fix count_vm_event preempt in memory compaction direct reclaim] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: compaction: add /sys trigger for per-node memory compactionMel Gorman
Add a per-node sysfs file called compact. When the file is written to, each zone in that node is compacted. The intention that this would be used by something like a job scheduler in a batch system before a job starts so that the job can allocate the maximum number of hugepages without significant start-up cost. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.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>
2010-05-25mm: compaction: add /proc trigger for memory compactionMel Gorman
Add a proc file /proc/sys/vm/compact_memory. When an arbitrary value is written to the file, all zones are compacted. The expected user of such a trigger is a job scheduler that prepares the system before the target application runs. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: compaction: memory compaction coreMel Gorman
This patch is the core of a mechanism which compacts memory in a zone by relocating movable pages towards the end of the zone. A single compaction run involves a migration scanner and a free scanner. Both scanners operate on pageblock-sized areas in the zone. The migration scanner starts at the bottom of the zone and searches for all movable pages within each area, isolating them onto a private list called migratelist. The free scanner starts at the top of the zone and searches for suitable areas and consumes the free pages within making them available for the migration scanner. The pages isolated for migration are then migrated to the newly isolated free pages. [aarcange@redhat.com: Fix unsafe optimisation] [mel@csn.ul.ie: do not schedule work on other CPUs for compaction] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: 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>
2010-05-25mm: move definition for LRU isolation modes to a headerMel Gorman
Currently, vmscan.c defines the isolation modes for __isolate_lru_page(). Memory compaction needs access to these modes for isolating pages for migration. This patch exports them. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <cl@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: 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>
2010-05-25mm: export fragmentation index via debugfsMel Gorman
The fragmentation fragmentation index, is only meaningful if an allocation would fail and indicates what the failure is due to. A value of -1 such as in many of the examples above states that the allocation would succeed. If it would fail, the value is between 0 and 1. A value tending towards 0 implies the allocation failed due to a lack of memory. A value tending towards 1 implies it failed due to external fragmentation. For the most part, the huge page size will be the size of interest but not necessarily so it is exported on a per-order and per-zo basis via /sys/kernel/debug/extfrag/extfrag_index > cat /sys/kernel/debug/extfrag/extfrag_index Node 0, zone DMA -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.00 Node 0, zone Normal -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 -1.000 0.954 Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: 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>
2010-05-25mm: export unusable free space index via debugfsMel Gorman
The unusable free space index measures how much of the available free memory cannot be used to satisfy an allocation of a given size and is a value between 0 and 1. The higher the value, the more of free memory is unusable and by implication, the worse the external fragmentation is. For the most part, the huge page size will be the size of interest but not necessarily so it is exported on a per-order and per-zone basis via /sys/kernel/debug/extfrag/unusable_index. > cat /sys/kernel/debug/extfrag/unusable_index Node 0, zone DMA 0.000 0.000 0.000 0.001 0.005 0.013 0.021 0.037 0.037 0.101 0.230 Node 0, zone Normal 0.000 0.000 0.000 0.001 0.002 0.002 0.005 0.015 0.028 0.028 0.054 [akpm@linux-foundation.org: Fix allnoconfig] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: 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>
2010-05-25mm: migration: avoid race between shift_arg_pages() and rmap_walk() during ↵Mel Gorman
migration by not migrating temporary stacks Page migration requires rmap to be able to find all ptes mapping a page at all times, otherwise the migration entry can be instantiated, but it is possible to leave one behind if the second rmap_walk fails to find the page. If this page is later faulted, migration_entry_to_page() will call BUG because the page is locked indicating the page was migrated by the migration PTE not cleaned up. For example kernel BUG at include/linux/swapops.h:105! invalid opcode: 0000 [#1] PREEMPT SMP ... Call Trace: [<ffffffff810e951a>] handle_mm_fault+0x3f8/0x76a [<ffffffff8130c7a2>] do_page_fault+0x44a/0x46e [<ffffffff813099b5>] page_fault+0x25/0x30 [<ffffffff8114de33>] load_elf_binary+0x152a/0x192b [<ffffffff8111329b>] search_binary_handler+0x173/0x313 [<ffffffff81114896>] do_execve+0x219/0x30a [<ffffffff8100a5c6>] sys_execve+0x43/0x5e [<ffffffff8100320a>] stub_execve+0x6a/0xc0 RIP [<ffffffff811094ff>] migration_entry_wait+0xc1/0x129 There is a race between shift_arg_pages and migration that triggers this bug. A temporary stack is setup during exec and later moved. If migration moves a page in the temporary stack and the VMA is then removed before migration completes, the migration PTE may not be found leading to a BUG when the stack is faulted. This patch causes pages within the temporary stack during exec to be skipped by migration. It does this by marking the VMA covering the temporary stack with an otherwise impossible combination of VMA flags. These flags are cleared when the temporary stack is moved to its final location. [kamezawa.hiroyu@jp.fujitsu.com: idea for having migration skip temporary stacks] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> 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>
2010-05-25mm: allow CONFIG_MIGRATION to be set without CONFIG_NUMA or memory hot-removeMel Gorman
CONFIG_MIGRATION currently depends on CONFIG_NUMA or on the architecture being able to hot-remove memory. The main users of page migration such as sys_move_pages(), sys_migrate_pages() and cpuset process migration are only beneficial on NUMA so it makes sense. As memory compaction will operate within a zone and is useful on both NUMA and non-NUMA systems, this patch allows CONFIG_MIGRATION to be set if the user selects CONFIG_COMPACTION as an option. [akpm@linux-foundation.org: Depend on CONFIG_HUGETLB_PAGE] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: 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>
2010-05-25mm: migration: allow the migration of PageSwapCache pagesMel Gorman
PageAnon pages that are unmapped may or may not have an anon_vma so are not currently migrated. However, a swap cache page can be migrated and fits this description. This patch identifies page swap caches and allows them to be migrated but ensures that no attempt to made to remap the pages would would potentially try to access an already freed anon_vma. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: migration: do not try to migrate unmapped anonymous pagesMel Gorman
rmap_walk_anon() was triggering errors in memory compaction that look like use-after-free errors. The problem is that between the page being isolated from the LRU and rcu_read_lock() being taken, the mapcount of the page dropped to 0 and the anon_vma gets freed. This can happen during memory compaction if pages being migrated belong to a process that exits before migration completes. Hence, the use-after-free race looks like 1. Page isolated for migration 2. Process exits 3. page_mapcount(page) drops to zero so anon_vma was no longer reliable 4. unmap_and_move() takes the rcu_lock but the anon_vma is already garbage 4. call try_to_unmap, looks up tha anon_vma and "locks" it but the lock is garbage. This patch checks the mapcount after the rcu lock is taken. If the mapcount is zero, the anon_vma is assumed to be freed and no further action is taken. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: migration: share the anon_vma ref counts between KSM and page migrationMel Gorman
For clarity of review, KSM and page migration have separate refcounts on the anon_vma. While clear, this is a waste of memory. This patch gets KSM and page migration to share their toys in a spirit of harmony. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: migration: take a reference to the anon_vma before migratingMel Gorman
This patchset is a memory compaction mechanism that reduces external fragmentation memory by moving GFP_MOVABLE pages to a fewer number of pageblocks. The term "compaction" was chosen as there are is a number of mechanisms that are not mutually exclusive that can be used to defragment memory. For example, lumpy reclaim is a form of defragmentation as was slub "defragmentation" (really a form of targeted reclaim). Hence, this is called "compaction" to distinguish it from other forms of defragmentation. In this implementation, a full compaction run involves two scanners operating within a zone - a migration and a free scanner. The migration scanner starts at the beginning of a zone and finds all movable pages within one pageblock_nr_pages-sized area and isolates them on a migratepages list. The free scanner begins at the end of the zone and searches on a per-area basis for enough free pages to migrate all the pages on the migratepages list. As each area is respectively migrated or exhausted of free pages, the scanners are advanced one area. A compaction run completes within a zone when the two scanners meet. This method is a bit primitive but is easy to understand and greater sophistication would require maintenance of counters on a per-pageblock basis. This would have a big impact on allocator fast-paths to improve compaction which is a poor trade-off. It also does not try relocate virtually contiguous pages to be physically contiguous. However, assuming transparent hugepages were in use, a hypothetical khugepaged might reuse compaction code to isolate free pages, split them and relocate userspace pages for promotion. Memory compaction can be triggered in one of three ways. It may be triggered explicitly by writing any value to /proc/sys/vm/compact_memory and compacting all of memory. It can be triggered on a per-node basis by writing any value to /sys/devices/system/node/nodeN/compact where N is the node ID to be compacted. When a process fails to allocate a high-order page, it may compact memory in an attempt to satisfy the allocation instead of entering direct reclaim. Explicit compaction does not finish until the two scanners meet and direct compaction ends if a suitable page becomes available that would meet watermarks. The series is in 14 patches. The first three are not "core" to the series but are important pre-requisites. Patch 1 reference counts anon_vma for rmap_walk_anon(). Without this patch, it's possible to use anon_vma after free if the caller is not holding a VMA or mmap_sem for the pages in question. While there should be no existing user that causes this problem, it's a requirement for memory compaction to be stable. The patch is at the start of the series for bisection reasons. Patch 2 merges the KSM and migrate counts. It could be merged with patch 1 but would be slightly harder to review. Patch 3 skips over unmapped anon pages during migration as there are no guarantees about the anon_vma existing. There is a window between when a page was isolated and migration started during which anon_vma could disappear. Patch 4 notes that PageSwapCache pages can still be migrated even if they are unmapped. Patch 5 allows CONFIG_MIGRATION to be set without CONFIG_NUMA Patch 6 exports a "unusable free space index" via debugfs. It's a measure of external fragmentation that takes the size of the allocation request into account. It can also be calculated from userspace so can be dropped if requested Patch 7 exports a "fragmentation index" which only has meaning when an allocation request fails. It determines if an allocation failure would be due to a lack of memory or external fragmentation. Patch 8 moves the definition for LRU isolation modes for use by compaction Patch 9 is the compaction mechanism although it's unreachable at this point Patch 10 adds a means of compacting all of memory with a proc trgger Patch 11 adds a means of compacting a specific node with a sysfs trigger Patch 12 adds "direct compaction" before "direct reclaim" if it is determined there is a good chance of success. Patch 13 adds a sysctl that allows tuning of the threshold at which the kernel will compact or direct reclaim Patch 14 temporarily disables compaction if an allocation failure occurs after compaction. Testing of compaction was in three stages. For the test, debugging, preempt, the sleep watchdog and lockdep were all enabled but nothing nasty popped out. min_free_kbytes was tuned as recommended by hugeadm to help fragmentation avoidance and high-order allocations. It was tested on X86, X86-64 and PPC64. Ths first test represents one of the easiest cases that can be faced for lumpy reclaim or memory compaction. 1. Machine freshly booted and configured for hugepage usage with a) hugeadm --create-global-mounts b) hugeadm --pool-pages-max DEFAULT:8G c) hugeadm --set-recommended-min_free_kbytes d) hugeadm --set-recommended-shmmax The min_free_kbytes here is important. Anti-fragmentation works best when pageblocks don't mix. hugeadm knows how to calculate a value that will significantly reduce the worst of external-fragmentation-related events as reported by the mm_page_alloc_extfrag tracepoint. 2. Load up memory a) Start updatedb b) Create in parallel a X files of pagesize*128 in size. Wait until files are created. By parallel, I mean that 4096 instances of dd were launched, one after the other using &. The crude objective being to mix filesystem metadata allocations with the buffer cache. c) Delete every second file so that pageblocks are likely to have holes d) kill updatedb if it's still running At this point, the system is quiet, memory is full but it's full with clean filesystem metadata and clean buffer cache that is unmapped. This is readily migrated or discarded so you'd expect lumpy reclaim to have no significant advantage over compaction but this is at the POC stage. 3. In increments, attempt to allocate 5% of memory as hugepages. Measure how long it took, how successful it was, how many direct reclaims took place and how how many compactions. Note the compaction figures might not fully add up as compactions can take place for orders other than the hugepage size X86 vanilla compaction Final page count 913 916 (attempted 1002) pages reclaimed 68296 9791 X86-64 vanilla compaction Final page count: 901 902 (attempted 1002) Total pages reclaimed: 112599 53234 PPC64 vanilla compaction Final page count: 93 94 (attempted 110) Total pages reclaimed: 103216 61838 There was not a dramatic improvement in success rates but it wouldn't be expected in this case either. What was important is that fewer pages were reclaimed in all cases reducing the amount of IO required to satisfy a huge page allocation. The second tests were all performance related - kernbench, netperf, iozone and sysbench. None showed anything too remarkable. The last test was a high-order allocation stress test. Many kernel compiles are started to fill memory with a pressured mix of unmovable and movable allocations. During this, an attempt is made to allocate 90% of memory as huge pages - one at a time with small delays between attempts to avoid flooding the IO queue. vanilla compaction Percentage of request allocated X86 98 99 Percentage of request allocated X86-64 95 98 Percentage of request allocated PPC64 55 70 This patch: rmap_walk_anon() does not use page_lock_anon_vma() for looking up and locking an anon_vma and it does not appear to have sufficient locking to ensure the anon_vma does not disappear from under it. This patch copies an approach used by KSM to take a reference on the anon_vma while pages are being migrated. This should prevent rmap_walk() running into nasty surprises later because anon_vma has been freed. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: 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>
2010-05-25mm: default to node zonelist ordering when nodes have only lowmemDavid Rientjes
There are two types of zonelist ordering methodologies: - node order, preferring allocations on a node to stay local to and - zone order, preferring allocations come from a higher zone to avoid allocating in lowmem zones even though they may not be local. The ordering technique used by the kernel is configurable on the command line, but also has some logic to determine what the default should be. This logic currently lacks knowledge of systems where a node may only have lowmem. For such systems, it is necessary to use node order so that GFP_KERNEL allocations may be satisfied by nodes consisting of only lowmem. If zone order is used, GFP_KERNEL allocations to such nodes are actually allocated on a node with local affinity that includes ZONE_NORMAL. This change defaults to node zonelist ordering if any node lacks ZONE_NORMAL. To force zone order, append 'numa_zonelist_order=zone' to the kernel command line. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: 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>
2010-05-25pagemap: add #ifdefs CONFIG_HUGETLB_PAGE on code walking hugetlb vmaNaoya Horiguchi
If !CONFIG_HUGETLB_PAGE, pagemap_hugetlb_range() is never called. So put it (and its calling function) into #ifdef block. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mincore: do nested page table walksJohannes Weiner
Do page table walks with the well-known nested loops we use in several other places already. This avoids doing full page table walks after every pte range and also allows to handle unmapped areas bigger than one pte range in one go. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mincore: pass ranges as start,end address pairsJohannes Weiner
Instead of passing a start address and a number of pages into the helper functions, convert them to use a start and an end address. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mincore: break do_mincore() into logical piecesJohannes Weiner
Split out functions to handle hugetlb ranges, pte ranges and unmapped ranges, to improve readability but also to prepare the file structure for nested page table walks. No semantic changes intended. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mincore: cleanupsJohannes Weiner
This fixes some minor issues that bugged me while going over the code: o adjust argument order of do_mincore() to match the syscall o simplify range length calculation o drop superfluous shift in huge tlb calculation, address is page aligned o drop dead nr_huge calculation o check pte_none() before pte_present() o comment and whitespace fixes No semantic changes intended. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25cpuset,mm: fix no node to alloc memory when changing cpuset's memsMiao Xie
Before applying this patch, cpuset updates task->mems_allowed and mempolicy by setting all new bits in the nodemask first, and clearing all old unallowed bits later. But in the way, the allocator may find that there is no node to alloc memory. The reason is that cpuset rebinds the task's mempolicy, it cleans the nodes which the allocater can alloc pages on, for example: (mpol: mempolicy) task1 task1's mpol task2 alloc page 1 alloc on node0? NO 1 1 change mems from 1 to 0 1 rebind task1's mpol 0-1 set new bits 0 clear disallowed bits alloc on node1? NO 0 ... can't alloc page goto oom This patch fixes this problem by expanding the nodes range first(set newly allowed bits) and shrink it lazily(clear newly disallowed bits). So we use a variable to tell the write-side task that read-side task is reading nodemask, and the write-side task clears newly disallowed nodes after read-side task ends the current memory allocation. [akpm@linux-foundation.org: fix spello] Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Menage <menage@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: restructure rebinding-mempolicy functionsMiao Xie
Nick Piggin reported that the allocator may see an empty nodemask when changing cpuset's mems[1]. It happens only on the kernel that do not do atomic nodemask_t stores. (MAX_NUMNODES > BITS_PER_LONG) But I found that there is also a problem on the kernel that can do atomic nodemask_t stores. The problem is that the allocator can't find a node to alloc page when changing cpuset's mems though there is a lot of free memory. The reason is like this: (mpol: mempolicy) task1 task1's mpol task2 alloc page 1 alloc on node0? NO 1 1 change mems from 1 to 0 1 rebind task1's mpol 0-1 set new bits 0 clear disallowed bits alloc on node1? NO 0 ... can't alloc page goto oom I can use the attached program reproduce it by the following step: # mkdir /dev/cpuset # mount -t cpuset cpuset /dev/cpuset # mkdir /dev/cpuset/1 # echo `cat /dev/cpuset/cpus` > /dev/cpuset/1/cpus # echo `cat /dev/cpuset/mems` > /dev/cpuset/1/mems # echo $$ > /dev/cpuset/1/tasks # numactl --membind=`cat /dev/cpuset/mems` ./cpuset_mem_hog <nr_tasks> & <nr_tasks> = max(nr_cpus - 1, 1) # killall -s SIGUSR1 cpuset_mem_hog # ./change_mems.sh several hours later, oom will happen though there is a lot of free memory. This patchset fixes this problem by expanding the nodes range first(set newly allowed bits) and shrink it lazily(clear newly disallowed bits). So we use a variable to tell the write-side task that read-side task is reading nodemask, and the write-side task clears newly disallowed nodes after read-side task ends the current memory allocation. This patch: In order to fix no node to alloc memory, when we want to update mempolicy and mems_allowed, we expand the set of nodes first (set all the newly nodes) and shrink the set of nodes lazily(clean disallowed nodes), But the mempolicy's rebind functions may breaks the expanding. So we restructure the mempolicy's rebind functions and split the rebind work to two steps, just like the update of cpuset's mems: The 1st step: expand the set of the mempolicy's nodes. The 2nd step: shrink the set of the mempolicy's nodes. It is used when there is no real lock to protect the mempolicy in the read-side. Otherwise we can do rebind work at once. In order to implement it, we define enum mpol_rebind_step { MPOL_REBIND_ONCE, MPOL_REBIND_STEP1, MPOL_REBIND_STEP2, MPOL_REBIND_NSTEP, }; If the mempolicy needn't be updated by two steps, we can pass MPOL_REBIND_ONCE to the rebind functions. Or we can pass MPOL_REBIND_STEP1 to do the first step of the rebind work and pass MPOL_REBIND_STEP2 to do the second step work. Besides that, it maybe long time between these two step and we have to release the lock that protects mempolicy and mems_allowed. If we hold the lock once again, we must check whether the current mempolicy is under the rebinding (the first step has been done) or not, because the task may alloc a new mempolicy when we don't hold the lock. So we defined the following flag to identify it: #define MPOL_F_REBINDING (1 << 2) The new functions will be used in the next patch. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Paul Menage <menage@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: document cpuset interaction with tmpfs mpol mount optionLee Schermerhorn
Update Documentation/filesystems/tmpfs.txt to describe the interaction of tmpfs mount option memory policy with tasks' cpuset mems_allowed. Note: the mount(8) man page [in the util-linux-ng package] requires similiar updates. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: factor mpol_shared_policy_init() return pathsLee Schermerhorn
Factor out duplicate put/frees in mpol_shared_policy_init() to a common return path. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: rename policy_types and cleanup initializationLee Schermerhorn
Rename 'policy_types[]' to 'policy_modes[]' to better match the array contents. Use designated intializer syntax for policy_modes[]. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: lose unnecessary loop variable in mpol_parse_str()Lee Schermerhorn
We don't really need the extra variable 'i' in mpol_parse_str(). The only use is as the the loop variable. Then, it's assigned to 'mode'. Just use mode, and loose the 'uninitialized_var()' macro. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: don't call mpol_set_nodemask() when no_contextLee Schermerhorn
No need to call mpol_set_nodemask() when we have no context for the mempolicy. This can occur when we're parsing a tmpfs 'mpol' mount option. Just save the raw nodemask in the mempolicy's w.user_nodemask member for use when a tmpfs/shmem file is created. mpol_shared_policy_init() will "contextualize" the policy for the new file based on the creating task's context. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Ravikiran Thirumalai <kiran@scalex86.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: remove redundant checkBob Liu
Lee's patch "mempolicy: use MPOL_PREFERRED for system-wide default policy" has made the MPOL_DEFAULT only used in the memory policy APIs. So, no need to check in __mpol_equal also. Also get rid of mpol_match_intent() and move its logic directly into __mpol_equal(). Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: remove case MPOL_INTERLEAVE from policy_zonelist()Bob Liu
In policy_zonelist() mode MPOL_INTERLEAVE shouldn't happen, so fall through to BUG() instead of break to return. I also fixed the comment. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mempolicy: remove redundant codeBob Liu
1. In funtion is_valid_nodemask(), varibable k will be inited to 0 in the following loop, needn't init to policy_zone anymore. 2. (MPOL_F_STATIC_NODES | MPOL_F_RELATIVE_NODES) has already defined to MPOL_MODE_FLAGS in mempolicy.h. Signed-off-by: Bob Liu <lliubbo@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25mm: remove return value of putback_lru_pages()Minchan Kim
putback_lru_page() never can fail. So it doesn't matter count of "the number of pages put back". In addition, users of this functions don't use return value. Let's remove unnecessary code. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.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>
2010-05-25shmem: remove redundant codeHuang Shijie
prep_new_page() will call set_page_private(page, 0) to initialise the page, so the code is redundant. Signed-off-by: Huang Shijie <shijie8@gmail.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25sparsemem: on no vmemmap path put mem_map on node high tooYinghai Lu
We need to put mem_map high when virtual memmap is not used. before this patch free mem pfn range on first node: [ 0.000000] 19 - 1f [ 0.000000] 28 40 - 80 95 [ 0.000000] 702 740 - 1000 1000 [ 0.000000] 347c - 347e [ 0.000000] 34e7 3500 - 3b80 3b8b [ 0.000000] 73b8b 73bc0 - 73c00 73c00 [ 0.000000] 73ddd - 73e00 [ 0.000000] 73fdd - 74000 [ 0.000000] 741dd - 74200 [ 0.000000] 743dd - 74400 [ 0.000000] 745dd - 74600 [ 0.000000] 747dd - 74800 [ 0.000000] 749dd - 74a00 [ 0.000000] 74bdd - 74c00 [ 0.000000] 74ddd - 74e00 [ 0.000000] 74fdd - 75000 [ 0.000000] 751dd - 75200 [ 0.000000] 753dd - 75400 [ 0.000000] 755dd - 75600 [ 0.000000] 757dd - 75800 [ 0.000000] 759dd - 75a00 [ 0.000000] 79bdd 79c00 - 7d540 7d550 [ 0.000000] 7f745 - 7f750 [ 0.000000] 10000b 100040 - 2080000 2080000 so only 79c00 - 7d540 are major free block under 4g... after this patch, we will get [ 0.000000] 19 - 1f [ 0.000000] 28 40 - 80 95 [ 0.000000] 702 740 - 1000 1000 [ 0.000000] 347c - 347e [ 0.000000] 34e7 3500 - 3600 3600 [ 0.000000] 37dd - 3800 [ 0.000000] 39dd - 3a00 [ 0.000000] 3bdd - 3c00 [ 0.000000] 3ddd - 3e00 [ 0.000000] 3fdd - 4000 [ 0.000000] 41dd - 4200 [ 0.000000] 43dd - 4400 [ 0.000000] 45dd - 4600 [ 0.000000] 47dd - 4800 [ 0.000000] 49dd - 4a00 [ 0.000000] 4bdd - 4c00 [ 0.000000] 4ddd - 4e00 [ 0.000000] 4fdd - 5000 [ 0.000000] 51dd - 5200 [ 0.000000] 53dd - 5400 [ 0.000000] 95dd 9600 - 7d540 7d550 [ 0.000000] 7f745 - 7f750 [ 0.000000] 17000b 170040 - 2080000 2080000 we will have 9600 - 7d540 for major free block... sparse-vmemmap path already used __alloc_bootmem_node_high() Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Jiri Slaby <jirislaby@gmail.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Greg Thelen <gthelen@google.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>
2010-05-25page allocator: reduce fragmentation in buddy allocator by adding buddies ↵Corrado Zoccolo
that are merging to the tail of the free lists In order to reduce fragmentation, this patch classifies freed pages in two groups according to their probability of being part of a high order merge. Pages belonging to a compound whose next-highest buddy is free are more likely to be part of a high order merge in the near future, so they will be added at the tail of the freelist. The remaining pages are put at the front of the freelist. In this way, the pages that are more likely to cause a big merge are kept free longer. Consequently there is a tendency to aggregate the long-living allocations on a subset of the compounds, reducing the fragmentation. This heuristic was tested on three machines, x86, x86-64 and ppc64 with 3GB of RAM in each machine. The tests were kernbench, netperf, sysbench and STREAM for performance and a high-order stress test for huge page allocations. KernBench X86 Elapsed mean 374.77 ( 0.00%) 375.10 (-0.09%) User mean 649.53 ( 0.00%) 650.44 (-0.14%) System mean 54.75 ( 0.00%) 54.18 ( 1.05%) CPU mean 187.75 ( 0.00%) 187.25 ( 0.27%) KernBench X86-64 Elapsed mean 94.45 ( 0.00%) 94.01 ( 0.47%) User mean 323.27 ( 0.00%) 322.66 ( 0.19%) System mean 36.71 ( 0.00%) 36.50 ( 0.57%) CPU mean 380.75 ( 0.00%) 381.75 (-0.26%) KernBench PPC64 Elapsed mean 173.45 ( 0.00%) 173.74 (-0.17%) User mean 587.99 ( 0.00%) 587.95 ( 0.01%) System mean 60.60 ( 0.00%) 60.57 ( 0.05%) CPU mean 373.50 ( 0.00%) 372.75 ( 0.20%) Nothing notable for kernbench. NetPerf UDP X86 64 42.68 ( 0.00%) 42.77 ( 0.21%) 128 85.62 ( 0.00%) 85.32 (-0.35%) 256 170.01 ( 0.00%) 168.76 (-0.74%) 1024 655.68 ( 0.00%) 652.33 (-0.51%) 2048 1262.39 ( 0.00%) 1248.61 (-1.10%) 3312 1958.41 ( 0.00%) 1944.61 (-0.71%) 4096 2345.63 ( 0.00%) 2318.83 (-1.16%) 8192 4132.90 ( 0.00%) 4089.50 (-1.06%) 16384 6770.88 ( 0.00%) 6642.05 (-1.94%)* NetPerf UDP X86-64 64 148.82 ( 0.00%) 154.92 ( 3.94%) 128 298.96 ( 0.00%) 312.95 ( 4.47%) 256 583.67 ( 0.00%) 626.39 ( 6.82%) 1024 2293.18 ( 0.00%) 2371.10 ( 3.29%) 2048 4274.16 ( 0.00%) 4396.83 ( 2.79%) 3312 6356.94 ( 0.00%) 6571.35 ( 3.26%) 4096 7422.68 ( 0.00%) 7635.42 ( 2.79%)* 8192 12114.81 ( 0.00%)* 12346.88 ( 1.88%) 16384 17022.28 ( 0.00%)* 17033.19 ( 0.06%)* 1.64% 2.73% NetPerf UDP PPC64 64 49.98 ( 0.00%) 50.25 ( 0.54%) 128 98.66 ( 0.00%) 100.95 ( 2.27%) 256 197.33 ( 0.00%) 191.03 (-3.30%) 1024 761.98 ( 0.00%) 785.07 ( 2.94%) 2048 1493.50 ( 0.00%) 1510.85 ( 1.15%) 3312 2303.95 ( 0.00%) 2271.72 (-1.42%) 4096 2774.56 ( 0.00%) 2773.06 (-0.05%) 8192 4918.31 ( 0.00%) 4793.59 (-2.60%) 16384 7497.98 ( 0.00%) 7749.52 ( 3.25%) The tests are run to have confidence limits within 1%. Results marked with a * were not confident although in this case, it's only outside by small amounts. Even with some results that were not confident, the netperf UDP results were generally positive. NetPerf TCP X86 64 652.25 ( 0.00%)* 648.12 (-0.64%)* 23.80% 22.82% 128 1229.98 ( 0.00%)* 1220.56 (-0.77%)* 21.03% 18.90% 256 2105.88 ( 0.00%) 1872.03 (-12.49%)* 1.00% 16.46% 1024 3476.46 ( 0.00%)* 3548.28 ( 2.02%)* 13.37% 11.39% 2048 4023.44 ( 0.00%)* 4231.45 ( 4.92%)* 9.76% 12.48% 3312 4348.88 ( 0.00%)* 4396.96 ( 1.09%)* 6.49% 8.75% 4096 4726.56 ( 0.00%)* 4877.71 ( 3.10%)* 9.85% 8.50% 8192 4732.28 ( 0.00%)* 5777.77 (18.10%)* 9.13% 13.04% 16384 5543.05 ( 0.00%)* 5906.24 ( 6.15%)* 7.73% 8.68% NETPERF TCP X86-64 netperf-tcp-vanilla-netperf netperf-tcp tcp-vanilla pgalloc-delay 64 1895.87 ( 0.00%)* 1775.07 (-6.81%)* 5.79% 4.78% 128 3571.03 ( 0.00%)* 3342.20 (-6.85%)* 3.68% 6.06% 256 5097.21 ( 0.00%)* 4859.43 (-4.89%)* 3.02% 2.10% 1024 8919.10 ( 0.00%)* 8892.49 (-0.30%)* 5.89% 6.55% 2048 10255.46 ( 0.00%)* 10449.39 ( 1.86%)* 7.08% 7.44% 3312 10839.90 ( 0.00%)* 10740.15 (-0.93%)* 6.87% 7.33% 4096 10814.84 ( 0.00%)* 10766.97 (-0.44%)* 6.86% 8.18% 8192 11606.89 ( 0.00%)* 11189.28 (-3.73%)* 7.49% 5.55% 16384 12554.88 ( 0.00%)* 12361.22 (-1.57%)* 7.36% 6.49% NETPERF TCP PPC64 netperf-tcp-vanilla-netperf netperf-tcp tcp-vanilla pgalloc-delay 64 594.17 ( 0.00%) 596.04 ( 0.31%)* 1.00% 2.29% 128 1064.87 ( 0.00%)* 1074.77 ( 0.92%)* 1.30% 1.40% 256 1852.46 ( 0.00%)* 1856.95 ( 0.24%) 1.25% 1.00% 1024 3839.46 ( 0.00%)* 3813.05 (-0.69%) 1.02% 1.00% 2048 4885.04 ( 0.00%)* 4881.97 (-0.06%)* 1.15% 1.04% 3312 5506.90 ( 0.00%) 5459.72 (-0.86%) 4096 6449.19 ( 0.00%) 6345.46 (-1.63%) 8192 7501.17 ( 0.00%) 7508.79 ( 0.10%) 16384 9618.65 ( 0.00%) 9490.10 (-1.35%) There was a distinct lack of confidence in the X86* figures so I included what the devation was where the results were not confident. Many of the results, whether gains or losses were within the standard deviation so no solid conclusion can be reached on performance impact. Looking at the figures, only the X86-64 ones look suspicious with a few losses that were outside the noise. However, the results were so unstable that without knowing why they vary so much, a solid conclusion cannot be reached. SYSBENCH X86 sysbench-vanilla pgalloc-delay 1 7722.85 ( 0.00%) 7756.79 ( 0.44%) 2 14901.11 ( 0.00%) 13683.44 (-8.90%) 3 15171.71 ( 0.00%) 14888.25 (-1.90%) 4 14966.98 ( 0.00%) 15029.67 ( 0.42%) 5 14370.47 ( 0.00%) 14865.00 ( 3.33%) 6 14870.33 ( 0.00%) 14845.57 (-0.17%) 7 14429.45 ( 0.00%) 14520.85 ( 0.63%) 8 14354.35 ( 0.00%) 14362.31 ( 0.06%) SYSBENCH X86-64 1 17448.70 ( 0.00%) 17484.41 ( 0.20%) 2 34276.39 ( 0.00%) 34251.00 (-0.07%) 3 50805.25 ( 0.00%) 50854.80 ( 0.10%) 4 66667.10 ( 0.00%) 66174.69 (-0.74%) 5 66003.91 ( 0.00%) 65685.25 (-0.49%) 6 64981.90 ( 0.00%) 65125.60 ( 0.22%) 7 64933.16 ( 0.00%) 64379.23 (-0.86%) 8 63353.30 ( 0.00%) 63281.22 (-0.11%) 9 63511.84 ( 0.00%) 63570.37 ( 0.09%) 10 62708.27 ( 0.00%) 63166.25 ( 0.73%) 11 62092.81 ( 0.00%) 61787.75 (-0.49%) 12 61330.11 ( 0.00%) 61036.34 (-0.48%) 13 61438.37 ( 0.00%) 61994.47 ( 0.90%) 14 62304.48 ( 0.00%) 62064.90 (-0.39%) 15 63296.48 ( 0.00%) 62875.16 (-0.67%) 16 63951.76 ( 0.00%) 63769.09 (-0.29%) SYSBENCH PPC64 -sysbench-pgalloc-delay-sysbench sysbench-vanilla pgalloc-delay 1 7645.08 ( 0.00%) 7467.43 (-2.38%) 2 14856.67 ( 0.00%) 14558.73 (-2.05%) 3 21952.31 ( 0.00%) 21683.64 (-1.24%) 4 27946.09 ( 0.00%) 28623.29 ( 2.37%) 5 28045.11 ( 0.00%) 28143.69 ( 0.35%) 6 27477.10 ( 0.00%) 27337.45 (-0.51%) 7 26489.17 ( 0.00%) 26590.06 ( 0.38%) 8 26642.91 ( 0.00%) 25274.33 (-5.41%) 9 25137.27 ( 0.00%) 24810.06 (-1.32%) 10 24451.99 ( 0.00%) 24275.85 (-0.73%) 11 23262.20 ( 0.00%) 23674.88 ( 1.74%) 12 24234.81 ( 0.00%) 23640.89 (-2.51%) 13 24577.75 ( 0.00%) 24433.50 (-0.59%) 14 25640.19 ( 0.00%) 25116.52 (-2.08%) 15 26188.84 ( 0.00%) 26181.36 (-0.03%) 16 26782.37 ( 0.00%) 26255.99 (-2.00%) Again, there is little to conclude here. While there are a few losses, the results vary by +/- 8% in some cases. They are the results of most concern as there are some large losses but it's also within the variance typically seen between kernel releases. The STREAM results varied so little and are so verbose that I didn't include them here. The final test stressed how many huge pages can be allocated. The absolute number of huge pages allocated are the same with or without the page. However, the "unusability free space index" which is a measure of external fragmentation was slightly lower (lower is better) throughout the lifetime of the system. I also measured the latency of how long it took to successfully allocate a huge page. The latency was slightly lower and on X86 and PPC64, more huge pages were allocated almost immediately from the free lists. The improvement is slight but there. [mel@csn.ul.ie: Tested, reworked for less branches] [czoccolo@gmail.com: fix oops by checking pfn_valid_within()] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux-foundation.org> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Corrado Zoccolo <czoccolo@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25tmpfs: insert tmpfs cache pages to inactive list at firstKOSAKI Motohiro
Shaohua Li reported parallel file copy on tmpfs can lead to OOM killer. This is regression of caused by commit 9ff473b9a7 ("vmscan: evict streaming IO first"). Wow, It is 2 years old patch! Currently, tmpfs file cache is inserted active list at first. This means that the insertion doesn't only increase numbers of pages in anon LRU, but it also reduces anon scanning ratio. Therefore, vmscan will get totally confused. It scans almost only file LRU even though the system has plenty unused tmpfs pages. Historically, lru_cache_add_active_anon() was used for two reasons. 1) Intend to priotize shmem page rather than regular file cache. 2) Intend to avoid reclaim priority inversion of used once pages. But we've lost both motivation because (1) Now we have separate anon and file LRU list. then, to insert active list doesn't help such priotize. (2) In past, one pte access bit will cause page activation. then to insert inactive list with pte access bit mean higher priority than to insert active list. Its priority inversion may lead to uninteded lru chun. but it was already solved by commit 645747462 (vmscan: detect mapped file pages used only once). (Thanks Hannes, you are great!) Thus, now we can use lru_cache_add_anon() instead. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reported-by: Shaohua Li <shaohua.li@intel.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25xtensa: includecheck fix: vectors.SJaswinder Singh Rajput
fix the following 'make includecheck' warnings: arch/xtensa/kernel/vectors.S: asm/processor.h is included more than once. arch/xtensa/kernel/vectors.S: asm/ptrace.h is included more than once. Signed-off-by: Jaswinder Singh Rajput <jaswinderrajput@gmail.com> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25xtensa: convert to asm-generic/hardirq.hChristoph Hellwig
Also remove lots of unused irq_cpustat fields. Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-25xtensa: set ARCH_KMALLOC_MINALIGNFUJITA Tomonori
Architectures that handle DMA-non-coherent memory need to set ARCH_KMALLOC_MINALIGN to make sure that kmalloc'ed buffer is DMA-safe: the buffer doesn't share a cache with the others. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Chris Zankel <chris@zankel.net> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6: cmd640: fix kernel oops in test_irq() method pdc202xx_old: ignore "FIFO empty" bit in test_irq() method pdc202xx_old: wire test_irq() method for PDC2026x IDE: pass IRQ flags to the IDE core ide: fix comment typo in ide.h
2010-05-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/vapier/blackfin: (30 commits) Blackfin: SMP: fix continuation lines Blackfin: acvilon: fix timeout usage for I2C Blackfin: fix typo in BF537 IRQ comment Blackfin: unify duplicate MEM_MT48LC32M8A2_75 kconfig options Blackfin: set ARCH_KMALLOC_MINALIGN Blackfin: use atomic kmalloc in L1 alloc so it too can be atomic Blackfin: another year of changes (update copyright in boot log) Blackfin: optimize strncpy a bit Blackfin: isram: clean up ITEST_COMMAND macro and improve the selftests Blackfin: move string functions to normal lib/ assembly Blackfin: SIC: cut down on IAR MMR reads a bit Blackfin: bf537-minotaur: fix build errors due to header changes Blackfin: kgdb: pass up the CC register instead of a 0 stub Blackfin: handle HW errors in the new "FAULT" printing code Blackfin: show the whole accumulator in the pseudo DBG insn Blackfin: support all possible registers in the pseudo instructions Blackfin: add support for the DBG (debug output) pseudo insn Blackfin: change the BUG opcode to an unused 16-bit opcode Blackfin: allow NMI watchdog to be used w/RETN as a scratch reg Blackfin: add support for the DBGA (debug assert) pseudo insn ...
2010-05-24Merge branch 'bkl/ioctl' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'bkl/ioctl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: uml: Pushdown the bkl from harddog_kern ioctl sunrpc: Pushdown the bkl from sunrpc cache ioctl sunrpc: Pushdown the bkl from ioctl autofs4: Pushdown the bkl from ioctl uml: Convert to unlocked_ioctls to remove implicit BKL ncpfs: BKL ioctl pushdown coda: Clean-up whitespace problems in pioctl.c coda: BKL ioctl pushdown drivers: Push down BKL into various drivers isdn: Push down BKL into ioctl functions scsi: Push down BKL into ioctl functions dvb: Push down BKL into ioctl functions smbfs: Push down BKL into ioctl function coda/psdev: Remove BKL from ioctl function um/mmapper: Remove BKL usage sn_hwperf: Kill BKL usage hfsplus: Push down BKL into ioctl function
2010-05-24Merge git://git.infradead.org/battery-2.6Linus Torvalds
* git://git.infradead.org/battery-2.6: ds2760_battery: Document ABI change ds2760_battery: Make charge_now and charge_full writeable power_supply: Add support for writeable properties power_supply: Use attribute groups power_supply: Add test_power driver tosa_battery: Fix build error due to direct driver_data usage wm97xx_battery: Quieten sparse warning (bat_set_pdata not declared) ds2782_battery: Get rid of magic numbers in driver_data ds2782_battery: Add support for ds2786 battery gas gauge pda_power: Add function callbacks for suspend and resume wm831x_power: Use genirq Driver for Zipit Z2 battery chip ds2782_battery: Fix clientdata on removal
2010-05-24Merge branch 'timers-for-linus-urgent' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus-urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: timers: Fix slack calculation for expired timers timekeeping: Fix timezone update
2010-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/lethal/sh-2.6: (25 commits) sh: fix up sh7785lcr_32bit_defconfig. arch/sh/lib/strlen.S: Checkpatch cleanup sh: fix up sh7786 dmaengine build. sh: guard cookie consistency across termination in the DMA driver sh: prevent the DMA driver from unloading, while in use sh: fix Oops in the serial SCI driver sh: allow platforms to specify SD-card supported voltages mmc: let MFD's provide supported Vdd card voltages to tmio_mmc sh: disable SD-card write-protection detection on kfr2r09 mfd: pass platform flags down to the tmio_mmc driver tmio: add a platform flag to disable card write-protection detection sh: Add SDHI DMA support to migor sh: Add SDHI DMA support to kfr2r09 sh: Add SDHI DMA support to ms7724se sh: Add SDHI DMA support to ecovec mmc: add DMA support to tmio_mmc driver, when used on SuperH sh: prepare the SDHI MFD driver to pass DMA configuration to tmio_mmc.c mmc: prepare tmio_mmc for passing of DMA configuration from the MFD cell sh: add DMA slave definitions to sh7724 sh: add DMA slaves for two SDHI controllers to sh7722 ...
2010-05-24Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osdLinus Torvalds
* 'for-linus' of git://git.open-osd.org/linux-open-osd: exofs: confusion between kmap() and kmap_atomic() api exofs: Add default address_space_operations
2010-05-24Revert "ath9k: Group Key fix for VAPs"Linus Torvalds
This reverts commit 03ceedea972a82d343fa5c2528b3952fa9e615d5, since it breaks resume from suspend-to-ram on Rafael's Acer Ferrari One. NetworkManager thinks everything is ok, but it can't connect to the AP to get an IP address after the resume. In fact, it even breaks resume for non-ath9k chipsets: reverting it also fixes Rafael's Toshiba Protege R500 with the iwlagn driver. As Johannes says: "Indeed, this patch needs to be reverted. That mac80211 change is wrong and completely unnecessary." Reported-and-requested-by: Rafael J. Wysocki <rjw@sisk.pl> Acked-by: Johannes Berg <johannes@sipsolutions.net> Cc: Daniel Yingqiang Ma <yma.cool@gmail.com> Cc: John W. Linville <linville@tuxdriver.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6Linus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/hirofumi/fatfs-2.6: fat: convert to unlocked_ioctl fat: Cleanup nls_unload() usage fat: use pack_hex_byte() instead of custom one
2010-05-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs: 9p: Optimize TCREATE by eliminating a redundant fid clone. 9p: cleanup: remove unneeded assignment 9p: Add mksock support fs/9p: Make sure we properly instantiate dentry. 9p: add 9P2000.L rename operation 9p: add 9P2000.L statfs operation 9p: VFS switches for 9p2000.L: VFS switches 9p: VFS switches for 9p2000.L: protocol and client changes
2010-05-24Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (59 commits) ceph: reuse mon subscribe message instead of allocated anew ceph: avoid resending queued message to monitor ceph: Storage class should be before const qualifier ceph: all allocation functions should get gfp_mask ceph: specify max_bytes on readdir replies ceph: cleanup pool op strings ceph: Use kzalloc ceph: use common helper for aborted dir request invalidation ceph: cope with out of order (unsafe after safe) mds reply ceph: save peer feature bits in connection structure ceph: resync headers with userland ceph: use ceph. prefix for virtual xattrs ceph: throw out dirty caps metadata, data on session teardown ceph: attempt mds reconnect if mds closes our session ceph: clean up send_mds_reconnect interface ceph: wait for mds OPEN reply to indicate reconnect success ceph: only send cap releases when mds is OPEN|HUNG ceph: dicard cap releases on mds restart ceph: make mon client statfs handling more generic ceph: drop src address(es) from message header [new protocol feature] ...
2010-05-24Merge branch 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6Linus Torvalds
* 'next-devicetree' of git://git.secretlab.ca/git/linux-2.6: of: change of_match_device to work with struct device of: Remove duplicate fields from of_platform_driver drivercore: Add of_match_table to the common device drivers arch/microblaze: Move dma_mask from of_device into pdev_archdata arch/powerpc: Move dma_mask from of_device into pdev_archdata of: eliminate of_device->node and dev_archdata->{of,prom}_node of: Always use 'struct device.of_node' to get device node pointer. i2c/of: Allow device node to be passed via i2c_board_info driver-core: Add device node pointer to struct device of: protect contents of of_platform.h and of_device.h of/flattree: Make unflatten_device_tree() safe to call from any arch of/flattree: make of_fdt.h safe to unconditionally include.