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* numa: introduce numa_mem_id()- effective local memory node idLee Schermerhorn2010-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce numa_mem_id(), based on generic percpu variable infrastructure to track "nearest node with memory" for archs that support memoryless nodes. Define API in <linux/topology.h> when CONFIG_HAVE_MEMORYLESS_NODES defined, else stubs. Architectures will define HAVE_MEMORYLESS_NODES if/when they support them. Archs can override definitions of: numa_mem_id() - returns node number of "local memory" node set_numa_mem() - initialize [this cpus'] per cpu variable 'numa_mem' cpu_to_mem() - return numa_mem for specified cpu; may be used as lvalue Generic initialization of 'numa_mem' occurs in __build_all_zonelists(). This will initialize the boot cpu at boot time, and all cpus on change of numa_zonelist_order, or when node or memory hot-plug requires zonelist rebuild. Archs that support memoryless nodes will need to initialize 'numa_mem' for secondary cpus as they're brought on-line. [akpm@linux-foundation.org: fix build] Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* numa: add generic percpu var numa_node_id() implementationLee Schermerhorn2010-05-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rework the generic version of the numa_node_id() function to use the new generic percpu variable infrastructure. Guard the new implementation with a new config option: CONFIG_USE_PERCPU_NUMA_NODE_ID. Archs which support this new implemention will default this option to 'y' when NUMA is configured. This config option could be removed if/when all archs switch over to the generic percpu implementation of numa_node_id(). Arch support involves: 1) converting any existing per cpu variable implementations to use this implementation. x86_64 is an instance of such an arch. 2) archs that don't use a per cpu variable for numa_node_id() will need to initialize the new per cpu variable "numa_node" as cpus are brought on-line. ia64 is an example. 3) Defining USE_PERCPU_NUMA_NODE_ID in arch dependent Kconfig--e.g., when NUMA is configured. This is required because I have retained the old implementation by default to allow archs to be modified incrementally, as desired. Subsequent patches will convert x86_64 and ia64 to use this implemenation. Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Tejun Heo <tj@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Eric Whitney <eric.whitney@hp.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: <linux-arch@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: fix potential race while building zonelist for new populated zoneHaicheng Li2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add global mutex zonelists_mutex to fix the possible race: CPU0 CPU1 CPU2 (1) zone->present_pages += online_pages; (2) build_all_zonelists(); (3) alloc_page(); (4) free_page(); (5) build_all_zonelists(); (6) __build_all_zonelists(); (7) zone->pageset = alloc_percpu(); In step (3,4), zone->pageset still points to boot_pageset, so bad things may happen if 2+ nodes are in this state. Even if only 1 node is accessing the boot_pageset, (3) may still consume too much memory to fail the memory allocations in step (7). Besides, atomic operation ensures alloc_percpu() in step (7) will never fail since there is a new fresh memory block added in step(6). [haicheng.li@linux.intel.com: hold zonelists_mutex when build_all_zonelists] Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Andi Kleen <andi.kleen@intel.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: avoid multiple zones sharing same boot strapping boot_pagesetHaicheng Li2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For each new populated zone of hotadded node, need to update its pagesets with dynamically allocated per_cpu_pageset struct for all possible CPUs: 1) Detach zone->pageset from the shared boot_pageset at end of __build_all_zonelists(). 2) Use mutex to protect zone->pageset when it's still shared in onlined_pages() Otherwises, multiple zones of different nodes would share same boot strapping boot_pageset for same CPU, which will finally cause below kernel panic: ------------[ cut here ]------------ kernel BUG at mm/page_alloc.c:1239! invalid opcode: 0000 [#1] SMP ... Call Trace: [<ffffffff811300c1>] __alloc_pages_nodemask+0x131/0x7b0 [<ffffffff81162e67>] alloc_pages_current+0x87/0xd0 [<ffffffff81128407>] __page_cache_alloc+0x67/0x70 [<ffffffff811325f0>] __do_page_cache_readahead+0x120/0x260 [<ffffffff81132751>] ra_submit+0x21/0x30 [<ffffffff811329c6>] ondemand_readahead+0x166/0x2c0 [<ffffffff81132ba0>] page_cache_async_readahead+0x80/0xa0 [<ffffffff8112a0e4>] generic_file_aio_read+0x364/0x670 [<ffffffff81266cfa>] nfs_file_read+0xca/0x130 [<ffffffff8117b20a>] do_sync_read+0xfa/0x140 [<ffffffff8117bf75>] vfs_read+0xb5/0x1a0 [<ffffffff8117c151>] sys_read+0x51/0x80 [<ffffffff8103c032>] system_call_fastpath+0x16/0x1b RIP [<ffffffff8112ff13>] get_page_from_freelist+0x883/0x900 RSP <ffff88000d1e78a8> ---[ end trace 4bda28328b9990db ] [akpm@linux-foundation.org: merge fix] Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Reviewed-by: Andi Kleen <andi.kleen@intel.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mem-hotplug: separate setup_per_cpu_pageset() into separate functionsWu Fengguang2010-05-25
| | | | | | | | | | | | | | | | No behavior change here. Move some of setup_per_cpu_pageset() code into a new function setup_zone_pageset() that will be useful for memory hotplug. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Haicheng Li <haicheng.li@linux.intel.com> Reviewed-by: Andi Kleen <andi.kleen@intel.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: introduce free_pages_prepare()KOSAKI Motohiro2010-05-25
| | | | | | | | | | | free_hot_cold_page() and __free_pages_ok() have very similar freeing preparation. Consolidate them. [akpm@linux-foundation.org: fix busted coding style] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: compaction: defer compaction using an exponential backoff when ↵Mel Gorman2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | compaction fails The fragmentation index may indicate that a failure is due to external fragmentation but after a compaction run completes, it is still possible for an allocation to fail. There are two obvious reasons as to why o Page migration cannot move all pages so fragmentation remains o A suitable page may exist but watermarks are not met In the event of compaction followed by an allocation failure, this patch defers further compaction in the zone (1 << compact_defer_shift) times. If the next compaction attempt also fails, compact_defer_shift is increased up to a maximum of 6. If compaction succeeds, the defer counters are reset again. The zone that is deferred is the first zone in the zonelist - i.e. the preferred zone. To defer compaction in the other zones, the information would need to be stored in the zonelist or implemented similar to the zonelist_cache. This would impact the fast-paths and is not justified at this time. Signed-off-by: Mel Gorman <mel@csn.ul.ie> 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>
* mm: compaction: direct compact when a high-order allocation failsMel Gorman2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm: compaction: memory compaction coreMel Gorman2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | 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>
* mm: default to node zonelist ordering when nodes have only lowmemDavid Rientjes2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* cpuset,mm: fix no node to alloc memory when changing cpuset's memsMiao Xie2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* page allocator: reduce fragmentation in buddy allocator by adding buddies ↵Corrado Zoccolo2010-05-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Fix typos in commentsThomas Weber2010-03-16
| | | | | | | | | | | [Ss]ytem => [Ss]ystem udpate => update paramters => parameters orginal => original Signed-off-by: Thomas Weber <swirl@gmx.li> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* mm: introduce dump_page() and print symbolic flag namesWu Fengguang2010-03-12
| | | | | | | | | | | | | | | | | | | | | | | | | | - introduce dump_page() to print the page info for debugging some error condition. - convert three mm users: bad_page(), print_bad_pte() and memory offline failure. - print an extra field: the symbolic names of page->flags Example dump_page() output: [ 157.521694] page:ffffea0000a7cba8 count:2 mapcount:1 mapping:ffff88001c901791 index:0x147 [ 157.525570] page flags: 0x100000000100068(uptodate|lru|active|swapbacked) Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alex Chiang <achiang@hp.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Mel Gorman <mel@linux.vnet.ibm.com> Cc: Christoph Lameter <cl@linux-foundation.org> 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>
* mm: do not iterate over NR_CPUS in __zone_pcp_update()Thomas Gleixner2010-03-12
| | | | | | | | | | | | | | | | | | | | | __zone_pcp_update() iterates over NR_CPUS instead of limiting the access to the possible cpus. This might result in access to uninitialized areas as the per cpu allocator only populates the per cpu memory for possible cpus. This problem was created as a result of the dynamic allocation of pagesets from percpu memory that went in during the merge window - commit 99dcc3e5a94ed491fbef402831d8c0bbb267f995 ("this_cpu: Page allocator conversion"). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Christoph Lameter <cl@linux-foundation.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: suppress pfn range output for zones without pagesDavid Rientjes2010-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | free_area_init_nodes() emits pfn ranges for all zones on the system. There may be no pages on a higher zone, however, due to memory limitations or the use of the mem= kernel parameter. For example: Zone PFN ranges: DMA 0x00000001 -> 0x00001000 DMA32 0x00001000 -> 0x00100000 Normal 0x00100000 -> 0x00100000 The implementation copies the previous zone's highest pfn, if any, as the next zone's lowest pfn. If its highest pfn is then greater than the amount of addressable memory, the upper memory limit is used instead. Thus, both the lowest and highest possible pfn for higher zones without memory may be the same. The pfn range for zones without memory is now shown as "empty" instead. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> 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>
* mm/pm: force GFP_NOIO during suspend/hibernation and resumeRafael J. Wysocki2010-03-06
| | | | | | | | | | | | | | | | | | | | There are quite a few GFP_KERNEL memory allocations made during suspend/hibernation and resume that may cause the system to hang, because the I/O operations they depend on cannot be completed due to the underlying devices being suspended. Avoid this problem by clearing the __GFP_IO and __GFP_FS bits in gfp_allowed_mask before suspend/hibernation and restoring the original values of these bits in gfp_allowed_mask durig the subsequent resume. [akpm@linux-foundation.org: fix CONFIG_PM=n linkage] Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Reported-by: Maxim Levitsky <maximlevitsky@gmail.com> Cc: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> 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>
* mm: restore zone->all_unreclaimable to independence wordKOSAKI Motohiro2010-03-06
| | | | | | | | | | | | | | | | | | | | commit e815af95 ("change all_unreclaimable zone member to flags") changed all_unreclaimable member to bit flag. But it had an undesireble side effect. free_one_page() is one of most hot path in linux kernel and increasing atomic ops in it can reduce kernel performance a bit. Thus, this patch revert such commit partially. at least all_unreclaimable shouldn't share memory word with other zone flags. [akpm@linux-foundation.org: fix patch interaction] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Huang Shijie <shijie8@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: remove free_hot_page()Li Hong2010-03-06
| | | | | | | | | | | | | | | | | | | free_hot_page() is just a wrapper around free_hot_cold_page() with parameter 'cold = 0'. After adding a clear comment for free_hot_cold_page(), it is reasonable to remove a level of call. [akpm@linux-foundation.org: fix build] Signed-off-by: Li Hong <lihong.hi@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Ming Chun <macli@brc.ubc.ca> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Americo Wang <xiyou.wangcong@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/page_alloc.c: adjust a call site to trace_mm_page_free_directLi Hong2010-03-06
| | | | | | | | | | | | | | | | | Move a call of trace_mm_page_free_direct() from free_hot_page() to free_hot_cold_page(). It is clearer and close to kmemcheck_free_shadow(), as it is done in function __free_pages_ok(). Signed-off-by: Li Hong <lihong.hi@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Ming Chun <macli@brc.ubc.ca> 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>
* mm/page_alloc.c: remove duplicate call to trace_mm_page_free_directLi Hong2010-03-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | trace_mm_page_free_direct() is called in function __free_pages(). But it is called again in free_hot_page() if order == 0 and produce duplicate records in trace file for mm_page_free_direct event. As below: K-PID CPU# TIMESTAMP FUNCTION gnome-terminal-1567 [000] 4415.246466: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0 gnome-terminal-1567 [000] 4415.246468: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0 gnome-terminal-1567 [000] 4415.246506: mm_page_alloc: page=ffffea0003db9f40 pfn=1155800 order=0 migratetype=0 gfp_flags=GFP_KERNEL gnome-terminal-1567 [000] 4415.255557: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0 gnome-terminal-1567 [000] 4415.255557: mm_page_free_direct: page=ffffea0003db9f40 pfn=1155800 order=0 This patch removes the first call and adds a call to trace_mm_page_free_direct() in __free_pages_ok(). Signed-off-by: Li Hong <lihong.hi@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Larry Woodman <lwoodman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Li Ming Chun <macli@brc.ubc.ca> 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>
* Merge branch 'x86-bootmem-for-linus' of ↵Linus Torvalds2010-03-03
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-bootmem-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (30 commits) early_res: Need to save the allocation name in drop_range_partial() sparsemem: Fix compilation on PowerPC early_res: Add free_early_partial() x86: Fix non-bootmem compilation on PowerPC core: Move early_res from arch/x86 to kernel/ x86: Add find_fw_memmap_area Move round_up/down to kernel.h x86: Make 32bit support NO_BOOTMEM early_res: Enhance check_and_double_early_res x86: Move back find_e820_area to e820.c x86: Add find_early_area_size x86: Separate early_res related code from e820.c x86: Move bios page reserve early to head32/64.c sparsemem: Put mem map for one node together. sparsemem: Put usemap for one node together x86: Make 64 bit use early_res instead of bootmem before slab x86: Only call dma32_reserve_bootmem 64bit !CONFIG_NUMA x86: Make early_node_mem get mem > 4 GB if possible x86: Dynamically increase early_res array size x86: Introduce max_early_res and early_res_count ...
| * x86: Fix non-bootmem compilation on PowerPCYinghai Lu2010-02-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These build errors on some non-x86 platforms (PowerPC for example): mm/page_alloc.c: In function '__alloc_memory_core_early': mm/page_alloc.c:3468: error: implicit declaration of function 'find_early_area' mm/page_alloc.c:3483: error: implicit declaration of function 'reserve_early_without_check' The function is only needed on CONFIG_NO_BOOTMEM. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Johannes Weiner <hannes@saeurebad.de> Cc: Mel Gorman <mel@csn.ul.ie> LKML-Reference: <4B747239.4070907@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * x86: Make 64 bit use early_res instead of bootmem before slabYinghai Lu2010-02-12
| | | | | | | | | | | | | | | | | | | | | | | | | | Finally we can use early_res to replace bootmem for x86_64 now. Still can use CONFIG_NO_BOOTMEM to enable it or not. -v2: fix 32bit compiling about MAX_DMA32_PFN -v3: folded bug fix from LKML message below Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4B747239.4070907@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | Merge branch 'master' into percpuTejun Heo2010-02-02
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| * mm: fix migratetype bug which slowed swappingHugh Dickins2010-01-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After memory pressure has forced it to dip into the reserves, 2.6.32's 5f8dcc21211a3d4e3a7a5ca366b469fb88117f61 "page-allocator: split per-cpu list into one-list-per-migrate-type" has been returning MIGRATE_RESERVE pages to the MIGRATE_MOVABLE free_list: in some sense depleting reserves. Fix that in the most straightforward way (which, considering the overheads of alternative approaches, is Mel's preference): the right migratetype is already in page_private(page), but free_pcppages_bulk() wasn't using it. How did this bug show up? As a 20% slowdown in my tmpfs loop kbuild swapping tests, on PowerMac G5 with SLUB allocator. Bisecting to that commit was easy, but explaining the magnitude of the slowdown not easy. The same effect appears, but much less markedly, with SLAB, and even less markedly on other machines (the PowerMac divides into fewer zones than x86, I think that may be a factor). We guess that lumpy reclaim of short-lived high-order pages is implicated in some way, and probably this bug has been tickling a poor decision somewhere in page reclaim. But instrumentation hasn't told me much, I've run out of time and imagination to determine exactly what's going on, and shouldn't hold up the fix any longer: it's valid, and might even fix other misbehaviours. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * page allocator: update NR_FREE_PAGES only when necessaryKOSAKI Motohiro2010-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit f2260e6b (page allocator: update NR_FREE_PAGES only as necessary) made one minor regression. if __rmqueue() was failed, NR_FREE_PAGES stat go wrong. this patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reported-by: Huang Shijie <shijie8@gmail.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/page_alloc: fix the range check for backward mergingKazuhisa Ichikawa2010-01-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current check for 'backward merging' within add_active_range() does not seem correct. start_pfn must be compared against early_node_map[i].start_pfn (and NOT against .end_pfn) to find out whether the new region is backward-mergeable with the existing range. Signed-off-by: Kazuhisa Ichikawa <ki@epsilou.com> Acked-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | this_cpu: Page allocator conversionChristoph Lameter2010-01-05
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the per cpu allocator functionality to avoid per cpu arrays in struct zone. This drastically reduces the size of struct zone for systems with large amounts of processors and allows placement of critical variables of struct zone in one cacheline even on very large systems. Another effect is that the pagesets of one processor are placed near one another. If multiple pagesets from different zones fit into one cacheline then additional cacheline fetches can be avoided on the hot paths when allocating memory from multiple zones. Bootstrap becomes simpler if we use the same scheme for UP, SMP, NUMA. #ifdefs are reduced and we can drop the zone_pcp macro. Hotplug handling is also simplified since cpu alloc can bring up and shut down cpu areas for a specific cpu as a whole. So there is no need to allocate or free individual pagesets. V7-V8: - Explain chicken egg dilemmna with percpu allocator. V4-V5: - Fix up cases where per_cpu_ptr is called before irq disable - Integrate the bootstrap logic that was separate before. tj: Build failure in pageset_cpuup_callback() due to missing ret variable fixed. Reviewed-by: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
* SYSCTL: Add a mutex to the page_alloc zone order sysctlAndi Kleen2009-12-23
| | | | | | | | The zone list code clearly cannot tolerate concurrent writers (I couldn't find any locks for that), so simply add a global mutex. No need for RCU in this case. Signed-off-by: Andi Kleen <ak@linux.intel.com>
* Merge branch 'merge' of ↵Linus Torvalds2009-12-22
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits) powerpc/gc/wii: Remove get_irq_desc() powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg powerpc/mpic: Fix problem that affinity is not updated powerpc/mm: Fix stupid bug in subpge protection handling powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion powerpc: Fix MSI support on U4 bridge PCIe slot powerpc: Handle VSX alignment faults correctly in little-endian mode powerpc/mm: Fix typo of cpumask_clear_cpu() powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled. powerpc: Convert BUG() to use unreachable() powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible. powerpc/pseries: Don't panic when H_PROD fails during cpu-online. powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs powerpc/defconfigs: Disable token ring in powerpc defconfigs powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules powerpc/pseries: Select XICS and PCI_MSI PSERIES powerpc/85xx: Wrong variable returned on error powerpc/iseries: Convert to proc_fops ...
| * mm: Add notifier in pageblock isolation for balloon driversRobert Jennings2009-12-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Memory balloon drivers can allocate a large amount of memory which is not movable but could be freed to accomodate memory hotplug remove. Prior to calling the memory hotplug notifier chain the memory in the pageblock is isolated. Currently, if the migrate type is not MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal for that page range to fail. Rather than failing pageblock isolation if the migrateteype is not MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock, and not on the LRU, are owned by a registered balloon driver (or other entity) using a notifier chain. If all of the non-movable pages are owned by a balloon, they can be freed later through the memory notifier chain and the range can still be isolated in set_migratetype_isolate(). Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Ingo Molnar <mingo@elte.hu> Cc: Brian King <brking@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Gerald Schaefer <geralds@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
* | Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds2009-12-19
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system Makefile: Unexport LC_ALL instead of clearing it x86: Fix objdump version check in arch/x86/tools/chkobjdump.awk x86: Reenable TSC sync check at boot, even with NONSTOP_TSC x86: Don't use POSIX character classes in gen-insn-attr-x86.awk Makefile: set LC_CTYPE, LC_COLLATE, LC_NUMERIC to C x86: Increase MAX_EARLY_RES; insufficient on 32-bit NUMA x86: Fix checking of SRAT when node 0 ram is not from 0 x86, cpuid: Add "volatile" to asm in native_cpuid() x86, msr: msrs_alloc/free for CONFIG_SMP=n x86, amd: Get multi-node CPU info from NodeId MSR instead of PCI config space x86: Add IA32_TSC_AUX MSR and use it x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers initramfs: add missing decompressor error check bzip2: Add missing checks for malloc returning NULL bzip2/lzma/gzip: pre-boot malloc doesn't return NULL on failure
| * x86: Fix checking of SRAT when node 0 ram is not from 0Yinghai Lu2009-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Found one system that boot from socket1 instead of socket0, SRAT get rejected... [ 0.000000] SRAT: Node 1 PXM 0 0-a0000 [ 0.000000] SRAT: Node 1 PXM 0 100000-80000000 [ 0.000000] SRAT: Node 1 PXM 0 100000000-2080000000 [ 0.000000] SRAT: Node 0 PXM 1 2080000000-4080000000 [ 0.000000] SRAT: Node 2 PXM 2 4080000000-6080000000 [ 0.000000] SRAT: Node 3 PXM 3 6080000000-8080000000 [ 0.000000] SRAT: Node 4 PXM 4 8080000000-a080000000 [ 0.000000] SRAT: Node 5 PXM 5 a080000000-c080000000 [ 0.000000] SRAT: Node 6 PXM 6 c080000000-e080000000 [ 0.000000] SRAT: Node 7 PXM 7 e080000000-10080000000 ... [ 0.000000] NUMA: Allocated memnodemap from 500000 - 701040 [ 0.000000] NUMA: Using 20 for the hash shift. [ 0.000000] Adding active range (0, 0x2080000, 0x4080000) 0 entries of 3200 used [ 0.000000] Adding active range (1, 0x0, 0x96) 1 entries of 3200 used [ 0.000000] Adding active range (1, 0x100, 0x7f750) 2 entries of 3200 used [ 0.000000] Adding active range (1, 0x100000, 0x2080000) 3 entries of 3200 used [ 0.000000] Adding active range (2, 0x4080000, 0x6080000) 4 entries of 3200 used [ 0.000000] Adding active range (3, 0x6080000, 0x8080000) 5 entries of 3200 used [ 0.000000] Adding active range (4, 0x8080000, 0xa080000) 6 entries of 3200 used [ 0.000000] Adding active range (5, 0xa080000, 0xc080000) 7 entries of 3200 used [ 0.000000] Adding active range (6, 0xc080000, 0xe080000) 8 entries of 3200 used [ 0.000000] Adding active range (7, 0xe080000, 0x10080000) 9 entries of 3200 used [ 0.000000] SRAT: PXMs only cover 917504MB of your 1048566MB e820 RAM. Not used. [ 0.000000] SRAT: SRAT not used. the early_node_map is not sorted because node0 with non zero start come first. so try to sort it right away after all regions are registered. also fixs refression by 8716273c (x86: Export srat physical topology) -v2: make it more solid to handle cross node case like node0 [0,4g), [8,12g) and node1 [4g, 8g), [12g, 16g) -v3: update comments. Reported-and-tested-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4B2579D2.3010201@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* | Merge branch 'hwpoison' of ↵Linus Torvalds2009-12-16
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits) HWPOISON: Remove stray phrase in a comment HWPOISON: Try to allocate migration page on the same node HWPOISON: Don't do early filtering if filter is disabled HWPOISON: Add a madvise() injector for soft page offlining HWPOISON: Add soft page offline support HWPOISON: Undefine short-hand macros after use to avoid namespace conflict HWPOISON: Use new shake_page in memory_failure HWPOISON: Use correct name for MADV_HWPOISON in documentation HWPOISON: mention HWPoison in Kconfig entry HWPOISON: Use get_user_page_fast in hwpoison madvise HWPOISON: add an interface to switch off/on all the page filters HWPOISON: add memory cgroup filter memcg: add accessor to mem_cgroup.css memcg: rename and export try_get_mem_cgroup_from_page() HWPOISON: add page flags filter mm: export stable page flags HWPOISON: limit hwpoison injector to known page types HWPOISON: add fs/device filters HWPOISON: return 0 to indicate success reliably HWPOISON: make semantics of IGNORED/DELAYED clear ...
| * | HWPOISON: detect free buddy pages explicitlyWu Fengguang2009-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Most free pages in the buddy system have no PG_buddy set. Introduce is_free_buddy_page() for detecting them reliably. CC: Nick Piggin <npiggin@suse.de> CC: Mel Gorman <mel@linux.vnet.ibm.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* | | oom-kill: fix NUMA constraint check with nodemaskKAMEZAWA Hiroyuki2009-12-16
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix node-oriented allocation handling in oom-kill.c I myself think of this as a bugfix not as an ehnancement. In these days, things are changed as - alloc_pages() eats nodemask as its arguments, __alloc_pages_nodemask(). - mempolicy don't maintain its own private zonelists. (And cpuset doesn't use nodemask for __alloc_pages_nodemask()) So, current oom-killer's check function is wrong. This patch does - check nodemask, if nodemask && nodemask doesn't cover all node_states[N_HIGH_MEMORY], this is CONSTRAINT_MEMORY_POLICY. - Scan all zonelist under nodemask, if it hits cpuset's wall this faiulre is from cpuset. And - modifies the caller of out_of_memory not to call oom if __GFP_THISNODE. This doesn't change "current" behavior. If callers use __GFP_THISNODE it should handle "page allocation failure" by itself. - handle __GFP_NOFAIL+__GFP_THISNODE path. This is something like a FIXME but this gfpmask is not used now. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hioryu@jp.fujitsu.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
* / mm: CONFIG_MMU for PG_mlockedHugh Dickins2009-12-15
|/ | | | | | | | | | | | | | | | | | | | | | | | Remove three degrees of obfuscation, left over from when we had CONFIG_UNEVICTABLE_LRU. MLOCK_PAGES is CONFIG_HAVE_MLOCKED_PAGE_BIT is CONFIG_HAVE_MLOCK is CONFIG_MMU. rmap.o (and memory-failure.o) are only built when CONFIG_MMU, so don't need such conditions at all. Somehow, I feel no compulsion to remove the CONFIG_HAVE_MLOCK* lines from 169 defconfigs: leave those to evolve in due course. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Izik Eidus <ieidus@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Nick Piggin <npiggin@suse.de> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* page allocator: Do not allow interrupts to use ALLOC_HARDERMel Gorman2009-11-12
| | | | | | | | | | | | | | | | | | | | | | Commit 341ce06f69abfafa31b9468410a13dbd60e2b237 ("page allocator: calculate the alloc_flags for allocation only once") altered watermark logic slightly by allowing rt_tasks that are handling an interrupt to set ALLOC_HARDER. This patch brings the watermark logic more in line with 2.6.30. This change results in a reduction of the number high-order GFP_ATOMIC allocation failures reported. See http://www.gossamer-threads.com/lists/linux/kernel/1144153 [rientjes@google.com: Spotted the problem] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* page allocator: always wake kswapd when restarting an allocation attempt ↵Mel Gorman2009-11-12
| | | | | | | | | | | | | | | | | | | | | | | | | | after direct reclaim failed If a direct reclaim makes no forward progress, it considers whether it should go OOM or not. Whether OOM is triggered or not, it may retry the allocation afterwards. In times past, this would always wake kswapd as well but currently, kswapd is not woken up after direct reclaim fails. For order-0 allocations, this makes little difference but if there is a heavy mix of higher-order allocations that direct reclaim is failing for, it might mean that kswapd is not rewoken for higher orders as much as it did previously. This patch wakes up kswapd when an allocation is being retried after a direct reclaim failure. It would be expected that kswapd is already awake, but this has the effect of telling kswapd to reclaim at the higher order as well. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* revert "mm: oom analysis: add buffer cache information to show_free_areas()"Andrew Morton2009-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | Revert commit 71de1ccbe1fb40203edd3beb473f8580d917d2ca Author: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> AuthorDate: Mon Sep 21 17:01:31 2009 -0700 Commit: Linus Torvalds <torvalds@linux-foundation.org> CommitDate: Tue Sep 22 07:17:27 2009 -0700 mm: oom analysis: add buffer cache information to show_free_areas() show_free_areas() is called during page allocation failures, and page allocation failures can occur in any calling context. But nr_blockdev_pages() takes VFS locks which should not be taken from hard IRQ context (at least). The result is lockdep warnings (and deadlockability) during page allocation failures. Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'hwpoison' of ↵Linus Torvalds2009-09-24
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits) HWPOISON: Enable error_remove_page on btrfs HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs HWPOISON: Add madvise() based injector for hardware poisoned pages v4 HWPOISON: Enable error_remove_page for NFS HWPOISON: Enable .remove_error_page for migration aware file systems HWPOISON: The high level memory error handler in the VM v7 HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process HWPOISON: shmem: call set_page_dirty() with locked page HWPOISON: Define a new error_remove_page address space op for async truncation HWPOISON: Add invalidate_inode_page HWPOISON: Refactor truncate to allow direct truncating of page v2 HWPOISON: check and isolate corrupted free pages v2 HWPOISON: Handle hardware poisoned pages in try_to_unmap HWPOISON: Use bitmask/action code for try_to_unmap behaviour HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2 HWPOISON: Add poison check to page fault handling HWPOISON: Add basic support for poisoned pages in fault handler v3 HWPOISON: Add new SIGBUS error codes for hardware poison signals HWPOISON: Add support for poison swap entries v2 HWPOISON: Export some rmap vma locking to outside world ...
| * HWPOISON: check and isolate corrupted free pages v2Wu Fengguang2009-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If memory corruption hits the free buddy pages, we can safely ignore them. No one will access them until page allocation time, then prep_new_page() will automatically check and isolate PG_hwpoison page for us (for 0-order allocation). This patch expands prep_new_page() to check every component page in a high order page allocation, in order to completely stop PG_hwpoison pages from being recirculated. Note that the common case -- only allocating a single page, doesn't do any more work than before. Allocating > order 0 does a bit more work, but that's relatively uncommon. This simple implementation may drop some innocent neighbor pages, hopefully it is not a big problem because the event should be rare enough. This patch adds some runtime costs to high order page users. [AK: Improved description] v2: Andi Kleen: Port to -mm code Move check into separate function. Don't dump stack in bad_pages for hwpoisoned pages. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* | sysctl: remove "struct file *" argument of ->proc_handlerAlexey Dobriyan2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's unused. It isn't needed -- read or write flag is already passed and sysctl shouldn't care about the rest. It _was_ used in two places at arch/frv for some reason. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: David Howells <dhowells@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "David S. Miller" <davem@davemloft.net> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: move highest_memmap_pfnHugh Dickins2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move highest_memmap_pfn __read_mostly from page_alloc.c next to zero_pfn __read_mostly in memory.c: to help them share a cacheline, since they're very often tested together in vm_normal_page(). Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | page-allocator: maintain rolling count of pages to free from the PCPMel Gorman2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When round-robin freeing pages from the PCP lists, empty lists may be encountered. In the event one of the lists has more pages than another, there may be numerous checks for list_empty() which is undesirable. This patch maintains a count of pages to free which is incremented when empty lists are encountered. The intention is that more pages will then be freed from fuller lists than the empty ones reducing the number of empty list checks in the free path. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | page-allocator: split per-cpu list into one-list-per-migrate-typeMel Gorman2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The following two patches remove searching in the page allocator fast-path by maintaining multiple free-lists in the per-cpu structure. At the time the search was introduced, increasing the per-cpu structures would waste a lot of memory as per-cpu structures were statically allocated at compile-time. This is no longer the case. The patches are as follows. They are based on mmotm-2009-08-27. Patch 1 adds multiple lists to struct per_cpu_pages, one per migratetype that can be stored on the PCP lists. Patch 2 notes that the pcpu drain path check empty lists multiple times. The patch reduces the number of checks by maintaining a count of free lists encountered. Lists containing pages will then free multiple pages in batch The patches were tested with kernbench, netperf udp/tcp, hackbench and sysbench. The netperf tests were not bound to any CPU in particular and were run such that the results should be 99% confidence that the reported results are within 1% of the estimated mean. sysbench was run with a postgres background and read-only tests. Similar to netperf, it was run multiple times so that it's 99% confidence results are within 1%. The patches were tested on x86, x86-64 and ppc64 as x86: Intel Pentium D 3GHz with 8G RAM (no-brand machine) kernbench - No significant difference, variance well within noise netperf-udp - 1.34% to 2.28% gain netperf-tcp - 0.45% to 1.22% gain hackbench - Small variances, very close to noise sysbench - Very small gains x86-64: AMD Phenom 9950 1.3GHz with 8G RAM (no-brand machine) kernbench - No significant difference, variance well within noise netperf-udp - 1.83% to 10.42% gains netperf-tcp - No conclusive until buffer >= PAGE_SIZE 4096 +15.83% 8192 + 0.34% (not significant) 16384 + 1% hackbench - Small gains, very close to noise sysbench - 0.79% to 1.6% gain ppc64: PPC970MP 2.5GHz with 10GB RAM (it's a terrasoft powerstation) kernbench - No significant difference, variance well within noise netperf-udp - 2-3% gain for almost all buffer sizes tested netperf-tcp - losses on small buffers, gains on larger buffers possibly indicates some bad caching effect. hackbench - No significant difference sysbench - 2-4% gain This patch: Currently the per-cpu page allocator searches the PCP list for pages of the correct migrate-type to reduce the possibility of pages being inappropriate placed from a fragmentation perspective. This search is potentially expensive in a fast-path and undesirable. Splitting the per-cpu list into multiple lists increases the size of a per-cpu structure and this was potentially a major problem at the time the search was introduced. These problem has been mitigated as now only the necessary number of structures is allocated for the running system. This patch replaces a list search in the per-cpu allocator with one list per migrate type. The potential snag with this approach is when bulk freeing pages. We round-robin free pages based on migrate type which has little bearing on the cache hotness of the page and potentially checks empty lists repeatedly in the event the majority of PCP pages are of one type. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Nick Piggin <npiggin@suse.de> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: do batched scans for mem_cgroupWu Fengguang2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For mem_cgroup, shrink_zone() may call shrink_list() with nr_to_scan=1, in which case shrink_list() _still_ calls isolate_pages() with the much larger SWAP_CLUSTER_MAX. It effectively scales up the inactive list scan rate by up to 32 times. For example, with 16k inactive pages and DEF_PRIORITY=12, (16k >> 12)=4. So when shrink_zone() expects to scan 4 pages in the active/inactive list, the active list will be scanned 4 pages, while the inactive list will be (over) scanned SWAP_CLUSTER_MAX=32 pages in effect. And that could break the balance between the two lists. It can further impact the scan of anon active list, due to the anon active/inactive ratio rebalance logic in balance_pgdat()/shrink_zone(): inactive anon list over scanned => inactive_anon_is_low() == TRUE => shrink_active_list() => active anon list over scanned So the end result may be - anon inactive => over scanned - anon active => over scanned (maybe not as much) - file inactive => over scanned - file active => under scanned (relatively) The accesses to nr_saved_scan are not lock protected and so not 100% accurate, however we can tolerate small errors and the resulted small imbalanced scan rates between zones. Cc: Rik van Riel <riel@redhat.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: also use alloc_large_system_hash() for the PID hash tableJan Beulich2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is being done by allowing boot time allocations to specify that they may want a sub-page sized amount of memory. Overall this seems more consistent with the other hash table allocations, and allows making two supposedly mm-only variables really mm-only (nr_{kernel,all}_pages). Signed-off-by: Jan Beulich <jbeulich@novell.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | page-allocator: limit the number of MIGRATE_RESERVE pageblocks per zoneMel Gorman2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After anti-fragmentation was merged, a bug was reported whereby devices that depended on high-order atomic allocations were failing. The solution was to preserve a property in the buddy allocator which tended to keep the minimum number of free pages in the zone at the lower physical addresses and contiguous. To preserve this property, MIGRATE_RESERVE was introduced and a number of pageblocks at the start of a zone would be marked "reserve", the number of which depended on min_free_kbytes. Anti-fragmentation works by avoiding the mixing of page migratetypes within the same pageblock. One way of helping this is to increase min_free_kbytes because it becomes less like that it will be necessary to place pages of of MIGRATE_RESERVE is unbounded, the free memory is kept there in large contiguous blocks instead of helping anti-fragmentation as much as it should. With the page-allocator tracepoint patches applied, it was found during anti-fragmentation tests that the number of fragmentation-related events were far higher than expected even with min_free_kbytes at higher values. This patch limits the number of MIGRATE_RESERVE blocks that exist per zone to two. For example, with a sufficient min_free_kbytes, 4MB of memory will be kept aside on an x86-64 and remain more or less free and contiguous for the systems uptime. This should be sufficient for devices depending on high-order atomic allocations while helping fragmentation control when min_free_kbytes is tuned appropriately. As side-effect of this patch is that the reserve variable is converted to int as unsigned long was the wrong type to use when ensuring that only the required number of reserve blocks are created. With the patches applied, fragmentation-related events as measured by the page allocator tracepoints were significantly reduced when running some fragmentation stress-tests on systems with min_free_kbytes tuned to a value appropriate for hugepage allocations at runtime. On x86, the events recorded were reduced by 99.8%, on x86-64 by 99.72% and on ppc64 by 99.83%. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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