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2011-10-31mm: neaten warn_alloc_failedJoe Perches1-5/+11
Add __attribute__((format (printf...) to the function to validate format and arguments. Use vsprintf extension %pV to avoid any possible message interleaving. Coalesce format string. Convert printks/pr_warning to pr_warn. [akpm@linux-foundation.org: use the __printf() macro] Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-10-31mm: output a list of loaded modules when we hit bad_page()Dave Jones1-0/+1
When we get a bad_page bug report, it's useful to see what modules the user had loaded. Signed-off-by: Dave Jones <davej@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-08-03fault-injection: add ability to export fault_attr in arbitrary directoryAkinobu Mita1-8/+5
init_fault_attr_dentries() is used to export fault_attr via debugfs. But it can only export it in debugfs root directory. Per Forlin is working on mmc_fail_request which adds support to inject data errors after a completed host transfer in MMC subsystem. The fault_attr for mmc_fail_request should be defined per mmc host and export it in debugfs directory per mmc host like /sys/kernel/debug/mmc0/mmc_fail_request. init_fault_attr_dentries() doesn't help for mmc_fail_request. So this introduces fault_create_debugfs_attr() which is able to create a directory in the arbitrary directory and replace init_fault_attr_dentries(). [akpm@linux-foundation.org: extraneous semicolon, per Randy] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Tested-by: Per Forlin <per.forlin@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26fail_page_alloc: simplify debugfs initializationAkinobu Mita1-31/+16
Now cleanup_fault_attr_dentries() recursively removes a directory, So we can simplify the error handling in the initialization code and no need to hold dentry structs for each debugfs file. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-26fault-injection: use debugfs_remove_recursiveAkinobu Mita1-1/+1
Use debugfs_remove_recursive() to simplify initialization and deinitialization of fault injection debugfs files. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25mm: page allocator: reconsider zones for allocation after direct reclaimMel Gorman1-0/+23
With zone_reclaim_mode enabled, it's possible for zones to be considered full in the zonelist_cache so they are skipped in the future. If the process enters direct reclaim, the ZLC may still consider zones to be full even after reclaiming pages. Reconsider all zones for allocation if direct reclaim returns successfully. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-25mm: page allocator: initialise ZLC for first zone eligible for zone_reclaimMel Gorman1-13/+22
There have been a small number of complaints about significant stalls while copying large amounts of data on NUMA machines reported on a distribution bugzilla. In these cases, zone_reclaim was enabled by default due to large NUMA distances. In general, the complaints have not been about the workload itself unless it was a file server (in which case the recommendation was disable zone_reclaim). The stalls are mostly due to significant amounts of time spent scanning the preferred zone for pages to free. After a failure, it might fallback to another node (as zonelists are often node-ordered rather than zone-ordered) but stall quickly again when the next allocation attempt occurs. In bad cases, each page allocated results in a full scan of the preferred zone. Patch 1 checks the preferred zone for recent allocation failure which is particularly important if zone_reclaim has failed recently. This avoids rescanning the zone in the near future and instead falling back to another node. This may hurt node locality in some cases but a failure to zone_reclaim is more expensive than a remote access. Patch 2 clears the zlc information after direct reclaim. Otherwise, zone_reclaim can mark zones full, direct reclaim can reclaim enough pages but the zone is still not considered for allocation. This was tested on a 24-thread 2-node x86_64 machine. The tests were focused on large amounts of IO. All tests were bound to the CPUs on node-0 to avoid disturbances due to processes being scheduled on different nodes. The kernels tested are 3.0-rc6-vanilla Vanilla 3.0-rc6 zlcfirst Patch 1 applied zlcreconsider Patches 1+2 applied FS-Mark ./fs_mark -d /tmp/fsmark-10813 -D 100 -N 5000 -n 208 -L 35 -t 24 -S0 -s 524288 fsmark-3.0-rc6 3.0-rc6 3.0-rc6 vanilla zlcfirs zlcreconsider Files/s min 54.90 ( 0.00%) 49.80 (-10.24%) 49.10 (-11.81%) Files/s mean 100.11 ( 0.00%) 135.17 (25.94%) 146.93 (31.87%) Files/s stddev 57.51 ( 0.00%) 138.97 (58.62%) 158.69 (63.76%) Files/s max 361.10 ( 0.00%) 834.40 (56.72%) 802.40 (55.00%) Overhead min 76704.00 ( 0.00%) 76501.00 ( 0.27%) 77784.00 (-1.39%) Overhead mean 1485356.51 ( 0.00%) 1035797.83 (43.40%) 1594680.26 (-6.86%) Overhead stddev 1848122.53 ( 0.00%) 881489.88 (109.66%) 1772354.90 ( 4.27%) Overhead max 7989060.00 ( 0.00%) 3369118.00 (137.13%) 10135324.00 (-21.18%) MMTests Statistics: duration User/Sys Time Running Test (seconds) 501.49 493.91 499.93 Total Elapsed Time (seconds) 2451.57 2257.48 2215.92 MMTests Statistics: vmstat Page Ins 46268 63840 66008 Page Outs 90821596 90671128 88043732 Swap Ins 0 0 0 Swap Outs 0 0 0 Direct pages scanned 13091697 8966863 8971790 Kswapd pages scanned 0 1830011 1831116 Kswapd pages reclaimed 0 1829068 1829930 Direct pages reclaimed 13037777 8956828 8648314 Kswapd efficiency 100% 99% 99% Kswapd velocity 0.000 810.643 826.346 Direct efficiency 99% 99% 96% Direct velocity 5340.128 3972.068 4048.788 Percentage direct scans 100% 83% 83% Page writes by reclaim 0 3 0 Slabs scanned 796672 720640 720256 Direct inode steals 7422667 7160012 7088638 Kswapd inode steals 0 1736840 2021238 Test completes far faster with a large increase in the number of files created per second. Standard deviation is high as a small number of iterations were much higher than the mean. The number of pages scanned by zone_reclaim is reduced and kswapd is used for more work. LARGE DD 3.0-rc6 3.0-rc6 3.0-rc6 vanilla zlcfirst zlcreconsider download tar 59 ( 0.00%) 59 ( 0.00%) 55 ( 7.27%) dd source files 527 ( 0.00%) 296 (78.04%) 320 (64.69%) delete source 36 ( 0.00%) 19 (89.47%) 20 (80.00%) MMTests Statistics: duration User/Sys Time Running Test (seconds) 125.03 118.98 122.01 Total Elapsed Time (seconds) 624.56 375.02 398.06 MMTests Statistics: vmstat Page Ins 3594216 439368 407032 Page Outs 23380832 23380488 23377444 Swap Ins 0 0 0 Swap Outs 0 436 287 Direct pages scanned 17482342 69315973 82864918 Kswapd pages scanned 0 519123 575425 Kswapd pages reclaimed 0 466501 522487 Direct pages reclaimed 5858054 2732949 2712547 Kswapd efficiency 100% 89% 90% Kswapd velocity 0.000 1384.254 1445.574 Direct efficiency 33% 3% 3% Direct velocity 27991.453 184832.737 208171.929 Percentage direct scans 100% 99% 99% Page writes by reclaim 0 5082 13917 Slabs scanned 17280 29952 35328 Direct inode steals 115257 1431122 332201 Kswapd inode steals 0 0 979532 This test downloads a large tarfile and copies it with dd a number of times - similar to the most recent bug report I've dealt with. Time to completion is reduced. The number of pages scanned directly is still disturbingly high with a low efficiency but this is likely due to the number of dirty pages encountered. The figures could probably be improved with more work around how kswapd is used and how dirty pages are handled but that is separate work and this result is significant on its own. Streaming Mapped Writer MMTests Statistics: duration User/Sys Time Running Test (seconds) 124.47 111.67 112.64 Total Elapsed Time (seconds) 2138.14 1816.30 1867.56 MMTests Statistics: vmstat Page Ins 90760 89124 89516 Page Outs 121028340 120199524 120736696 Swap Ins 0 86 55 Swap Outs 0 0 0 Direct pages scanned 114989363 96461439 96330619 Kswapd pages scanned 56430948 56965763 57075875 Kswapd pages reclaimed 27743219 27752044 27766606 Direct pages reclaimed 49777 46884 36655 Kswapd efficiency 49% 48% 48% Kswapd velocity 26392.541 31363.631 30561.736 Direct efficiency 0% 0% 0% Direct velocity 53780.091 53108.759 51581.004 Percentage direct scans 67% 62% 62% Page writes by reclaim 385 122 1513 Slabs scanned 43008 39040 42112 Direct inode steals 0 10 8 Kswapd inode steals 733 534 477 This test just creates a large file mapping and writes to it linearly. Time to completion is again reduced. The gains are mostly down to two things. In many cases, there is less scanning as zone_reclaim simply gives up faster due to recent failures. The second reason is that memory is used more efficiently. Instead of scanning the preferred zone every time, the allocator falls back to another zone and uses it instead improving overall memory utilisation. This patch: initialise ZLC for first zone eligible for zone_reclaim. The zonelist cache (ZLC) is used among other things to record if zone_reclaim() failed for a particular zone recently. The intention is to avoid a high cost scanning extremely long zonelists or scanning within the zone uselessly. Currently the zonelist cache is setup only after the first zone has been considered and zone_reclaim() has been called. The objective was to avoid a costly setup but zone_reclaim is itself quite expensive. If it is failing regularly such as the first eligible zone having mostly mapped pages, the cost in scanning and allocation stalls is far higher than the ZLC initialisation step. This patch initialises ZLC before the first eligible zone calls zone_reclaim(). Once initialised, it is checked whether the zone failed zone_reclaim recently. If it has, the zone is skipped. As the first zone is now being checked, additional care has to be taken about zones marked full. A zone can be marked "full" because it should not have enough unmapped pages for zone_reclaim but this is excessive as direct reclaim or kswapd may succeed where zone_reclaim fails. Only mark zones "full" after zone_reclaim fails if it failed to reclaim enough pages after scanning. Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-12x86, numa: Implement pfn -> nid mapping granularity checkTejun Heo1-0/+54
SPARSEMEM w/o VMEMMAP and DISCONTIGMEM, both used only on 32bit, use sections array to map pfn to nid which is limited in granularity. If NUMA nodes are laid out such that the mapping cannot be accurate, boot will fail triggering BUG_ON() in mminit_verify_page_links(). On 32bit, it's 512MiB w/ PAE and SPARSEMEM. This seems to have been granular enough until commit 2706a0bf7b (x86, NUMA: Enable CONFIG_AMD_NUMA on 32bit too). Apparently, there is a machine which aligns NUMA nodes to 128MiB and has only AMD NUMA but not SRAT. This led to the following BUG_ON(). On node 0 totalpages: 2096615 DMA zone: 32 pages used for memmap DMA zone: 0 pages reserved DMA zone: 3927 pages, LIFO batch:0 Normal zone: 1740 pages used for memmap Normal zone: 220978 pages, LIFO batch:31 HighMem zone: 16405 pages used for memmap HighMem zone: 1853533 pages, LIFO batch:31 BUG: Int 6: CR2 (null) EDI (null) ESI 00000002 EBP 00000002 ESP c1543ecc EBX f2400000 EDX 00000006 ECX (null) EAX 00000001 err (null) EIP c16209aa CS 00000060 flg 00010002 Stack: f2400000 00220000 f7200800 c1620613 00220000 01000000 04400000 00238000 (null) f7200000 00000002 f7200b58 f7200800 c1620929 000375fe (null) f7200b80 c16395f0 00200a02 f7200a80 (null) 000375fe 00000002 (null) Pid: 0, comm: swapper Not tainted 2.6.39-rc5-00181-g2706a0b #17 Call Trace: [<c136b1e5>] ? early_fault+0x2e/0x2e [<c16209aa>] ? mminit_verify_page_links+0x12/0x42 [<c1620613>] ? memmap_init_zone+0xaf/0x10c [<c1620929>] ? free_area_init_node+0x2b9/0x2e3 [<c1607e99>] ? free_area_init_nodes+0x3f2/0x451 [<c1601d80>] ? paging_init+0x112/0x118 [<c15f578d>] ? setup_arch+0x791/0x82f [<c15f43d9>] ? start_kernel+0x6a/0x257 This patch implements node_map_pfn_alignment() which determines maximum internode alignment and update numa_register_memblks() to reject NUMA configuration if alignment exceeds the pfn -> nid mapping granularity of the memory model as determined by PAGES_PER_SECTION. This makes the problematic machine boot w/ flatmem by rejecting the NUMA config and provides protection against crazy NUMA configurations. Signed-off-by: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/20110712074534.GB2872@htj.dyndns.org LKML-Reference: <20110628174613.GP478@escobedo.osrc.amd.com> Reported-and-Tested-by: Hans Rosenfeld <hans.rosenfeld@amd.com> Cc: Conny Seidel <conny.seidel@amd.com> Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-06-02Revert "mm: fail GFP_DMA allocations when ZONE_DMA is not configured"Linus Torvalds1-4/+0
This reverts commit a197b59ae6e8bee56fcef37ea2482dc08414e2ac. As rmk says: "Commit a197b59ae6e8 (mm: fail GFP_DMA allocations when ZONE_DMA is not configured) is causing regressions on ARM with various drivers which use GFP_DMA. The behaviour up until now has been to silently ignore that flag when CONFIG_ZONE_DMA is not enabled, and to allocate from the normal zone. However, as a result of the above commit, such allocations now fail which causes drivers to fail. These are regressions compared to the previous kernel version." so just revert it. Requested-by: Russell King <linux@arm.linux.org.uk> Acked-by: Andrew Morton <akpm@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-26memcg: fix get_scan_count() for small targetsKAMEZAWA Hiroyuki1-3/+1
During memory reclaim we determine the number of pages to be scanned per zone as (anon + file) >> priority. Assume scan = (anon + file) >> priority. If scan < SWAP_CLUSTER_MAX, the scan will be skipped for this time and priority gets higher. This has some problems. 1. This increases priority as 1 without any scan. To do scan in this priority, amount of pages should be larger than 512M. If pages>>priority < SWAP_CLUSTER_MAX, it's recorded and scan will be batched, later. (But we lose 1 priority.) If memory size is below 16M, pages >> priority is 0 and no scan in DEF_PRIORITY forever. 2. If zone->all_unreclaimabe==true, it's scanned only when priority==0. So, x86's ZONE_DMA will never be recoverred until the user of pages frees memory by itself. 3. With memcg, the limit of memory can be small. When using small memcg, it gets priority < DEF_PRIORITY-2 very easily and need to call wait_iff_congested(). For doing scan before priorty=9, 64MB of memory should be used. Then, this patch tries to scan SWAP_CLUSTER_MAX of pages in force...when 1. the target is enough small. 2. it's kswapd or memcg reclaim. Then we can avoid rapid priority drop and may be able to recover all_unreclaimable in a small zones. And this patch removes nr_saved_scan. This will allow scanning in this priority even when pages >> priority is very small. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Ying Han <yinghan@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> 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>
2011-05-25mm/page_alloc.c: prevent unending loop in __alloc_pages_slowpath()Andrew Barry1-1/+1
I believe I found a problem in __alloc_pages_slowpath, which allows a process to get stuck endlessly looping, even when lots of memory is available. Running an I/O and memory intensive stress-test I see a 0-order page allocation with __GFP_IO and __GFP_WAIT, running on a system with very little free memory. Right about the same time that the stress-test gets killed by the OOM-killer, the utility trying to allocate memory gets stuck in __alloc_pages_slowpath even though most of the systems memory was freed by the oom-kill of the stress-test. The utility ends up looping from the rebalance label down through the wait_iff_congested continiously. Because order=0, __alloc_pages_direct_compact skips the call to get_page_from_freelist. Because all of the reclaimable memory on the system has already been reclaimed, __alloc_pages_direct_reclaim skips the call to get_page_from_freelist. Since there is no __GFP_FS flag, the block with __alloc_pages_may_oom is skipped. The loop hits the wait_iff_congested, then jumps back to rebalance without ever trying to get_page_from_freelist. This loop repeats infinitely. The test case is pretty pathological. Running a mix of I/O stress-tests that do a lot of fork() and consume all of the system memory, I can pretty reliably hit this on 600 nodes, in about 12 hours. 32GB/node. Signed-off-by: Andrew Barry <abarry@cray.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel<riel@redhat.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm: fail GFP_DMA allocations when ZONE_DMA is not configuredDavid Rientjes1-0/+4
The page allocator will improperly return a page from ZONE_NORMAL even when __GFP_DMA is passed if CONFIG_ZONE_DMA is disabled. The caller expects DMA memory, perhaps for ISA devices with 16-bit address registers, and may get higher memory resulting in undefined behavior. This patch causes the page allocator to return NULL in such circumstances with a warning emitted to the kernel log on the first occurrence. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: 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>
2011-05-25mm: check if any page in a pageblock is reserved before marking it ↵Arve Hjønnevåg1-2/+17
MIGRATE_RESERVE This fixes a problem where the first pageblock got marked MIGRATE_RESERVE even though it only had a few free pages. eg, On current ARM port, The kernel starts at offset 0x8000 to leave room for boot parameters, and the memory is freed later. This in turn caused no contiguous memory to be reserved and frequent kswapd wakeups that emptied the caches to get more contiguous memory. Unfortunatelly, ARM needs order-2 allocation for pgd (see arm/mm/pgd.c#pgd_alloc()). Therefore the issue is not minor nor easy avoidable. [kosaki.motohiro@jp.fujitsu.com: added some explanation] [kosaki.motohiro@jp.fujitsu.com: add !pfn_valid_within() to check] [minchan.kim@gmail.com: check end_pfn in pageblock_is_reserved] Signed-off-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Arve Hjønnevåg <arve@android.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm: break out page allocation warning codeDave Hansen1-21/+41
This originally started as a simple patch to give vmalloc() some more verbose output on failure on top of the plain page allocator messages. Johannes suggested that it might be nicer to lead with the vmalloc() info _before_ the page allocator messages. But, I do think there's a lot of value in what __alloc_pages_slowpath() does with its filtering and so forth. This patch creates a new function which other allocators can call instead of relying on the internal page allocator warnings. It also gives this function private rate-limiting which separates it from other printk_ratelimit() users. Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Cc: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm/compaction: reverse the change that forbade sync migraton with ↵Andrea Arcangeli1-1/+1
__GFP_NO_KSWAPD It's uncertain this has been beneficial, so it's safer to undo it. All other compaction users would still go in synchronous mode if a first attempt at async compaction failed. Hopefully we don't need to force special behavior for THP (which is the only __GFP_NO_KSWAPD user so far and it's the easier to exercise and to be noticeable). This also make __GFP_NO_KSWAPD return to its original strict semantics specific to bypass kswapd, as THP allocations have khugepaged for the async THP allocations/compactions. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: Alex Villacis Lasso <avillaci@fiec.espol.edu.ec> 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>
2011-05-25mm, mem-hotplug: update pcp->stat_threshold when memory hotplug occurKOSAKI Motohiro1-0/+2
Currently, cpu hotplug updates pcp->stat_threshold, but memory hotplug doesn't. There is no reason for this. [akpm@linux-foundation.org: fix CONFIG_SMP=n build] Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm, mem-hotplug: recalculate lowmem_reserve when memory hotplug occursKOSAKI Motohiro1-2/+2
Currently, memory hotplug calls setup_per_zone_wmarks() and calculate_zone_inactive_ratio(), but doesn't call setup_per_zone_lowmem_reserve(). It means the number of reserved pages aren't updated even if memory hot plug occur. This patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25mm, mem-hotplug: fix section mismatch. setup_per_zone_inactive_ratio() ↵KOSAKI Motohiro1-2/+2
should be __meminit. Commit bce7394a3e ("page-allocator: reset wmark_min and inactive ratio of zone when hotplug happens") introduced invalid section references. Now, setup_per_zone_inactive_ratio() is marked __init and then it can't be referenced from memory hotplug code. This patch marks it as __meminit and also marks caller as __ref. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> 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>
2011-05-25mm: remove unused zone_idx variable from set_migratetype_isolateSergey Senozhatsky1-2/+0
Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Reviewed-by: Christoph Lameter <cl@linux.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-25arch, mm: filter disallowed nodes from arch specific show_mem functionsDavid Rientjes1-14/+8
Architectures that implement their own show_mem() function did not pass the filter argument to show_free_areas() to appropriately avoid emitting the state of nodes that are disallowed in the current context. This patch now passes the filter argument to show_free_areas() so those nodes are now avoided. This patch also removes the show_free_areas() wrapper around __show_free_areas() and converts existing callers to pass an empty filter. ia64 emits additional information for each node, so skip_free_areas_zone() must be made global to filter disallowed nodes and it is converted to use a nid argument rather than a zone for this use case. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Helge Deller <deller@gmx.de> Cc: James Bottomley <jejb@parisc-linux.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-23Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits) b43: fix comment typo reqest -> request Haavard Skinnemoen has left Atmel cris: typo in mach-fs Makefile Kconfig: fix copy/paste-ism for dell-wmi-aio driver doc: timers-howto: fix a typo ("unsgined") perf: Only include annotate.h once in tools/perf/util/ui/browsers/annotate.c md, raid5: Fix spelling error in comment ('Ofcourse' --> 'Of course'). treewide: fix a few typos in comments regulator: change debug statement be consistent with the style of the rest Revert "arm: mach-u300/gpio: Fix mem_region resource size miscalculations" audit: acquire creds selectively to reduce atomic op overhead rtlwifi: don't touch with treewide double semicolon removal treewide: cleanup continuations and remove logging message whitespace ath9k_hw: don't touch with treewide double semicolon removal include/linux/leds-regulator.h: fix syntax in example code tty: fix typo in descripton of tty_termios_encode_baud_rate xtensa: remove obsolete BKL kernel option from defconfig m68k: fix comment typo 'occcured' arch:Kconfig.locks Remove unused config option. treewide: remove extra semicolons ...
2011-05-20sanitize <linux/prefetch.h> usageLinus Torvalds1-0/+1
Commit e66eed651fd1 ("list: remove prefetching from regular list iterators") removed the include of prefetch.h from list.h, which uncovered several cases that had apparently relied on that rather obscure header file dependency. So this fixes things up a bit, using grep -L linux/prefetch.h $(git grep -l '[^a-z_]prefetchw*(' -- '*.[ch]') grep -L 'prefetchw*(' $(git grep -l 'linux/prefetch.h' -- '*.[ch]') to guide us in finding files that either need <linux/prefetch.h> inclusion, or have it despite not needing it. There are more of them around (mostly network drivers), but this gets many core ones. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-16mm: fix kernel-doc warning in page_alloc.cRandy Dunlap1-0/+1
Fix new kernel-doc warning in mm/page_alloc.c: Warning(mm/page_alloc.c:2370): No description found for parameter 'nid' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-11mm: add alloc_pages_exact_nid()Andi Kleen1-12/+37
Add a alloc_pages_exact_nid() that allocates on a specific node. The naming is quite broken, but fixing that would need a larger renaming action. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: tweak comment] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-11mm: use alloc_bootmem_node_nopanic() on really needed pathYinghai Lu1-3/+4
Stefan found nobootmem does not work on his system that has only 8M of RAM. This causes an early panic: BIOS-provided physical RAM map: BIOS-88: 0000000000000000 - 000000000009f000 (usable) BIOS-88: 0000000000100000 - 0000000000840000 (usable) bootconsole [earlyser0] enabled Notice: NX (Execute Disable) protection missing in CPU or disabled in BIOS! DMI not present or invalid. last_pfn = 0x840 max_arch_pfn = 0x100000 init_memory_mapping: 0000000000000000-0000000000840000 8MB LOWMEM available. mapped low ram: 0 - 00840000 low ram: 0 - 00840000 Zone PFN ranges: DMA 0x00000001 -> 0x00001000 Normal empty Movable zone start PFN for each node early_node_map[2] active PFN ranges 0: 0x00000001 -> 0x0000009f 0: 0x00000100 -> 0x00000840 BUG: Int 6: CR2 (null) EDI c034663c ESI (null) EBP c0329f38 ESP c0329ef4 EBX c0346380 EDX 00000006 ECX ffffffff EAX fffffff4 err (null) EIP c0353191 CS c0320060 flg 00010082 Stack: (null) c030c533 000007cd (null) c030c533 00000001 (null) (null) 00000003 0000083f 00000018 00000002 00000002 c0329f6c c03534d6 (null) (null) 00000100 00000840 (null) c0329f64 00000001 00001000 (null) Pid: 0, comm: swapper Not tainted 2.6.36 #5 Call Trace: [<c02e3707>] ? 0xc02e3707 [<c035e6e5>] 0xc035e6e5 [<c0353191>] ? 0xc0353191 [<c03534d6>] 0xc03534d6 [<c034f1cd>] 0xc034f1cd [<c034a824>] 0xc034a824 [<c03513cb>] ? 0xc03513cb [<c0349432>] 0xc0349432 [<c0349066>] 0xc0349066 It turns out that we should ignore the low limit of 16M. Use alloc_bootmem_node_nopanic() in this case. [akpm@linux-foundation.org: less mess] Signed-off-by: Yinghai LU <yinghai@kernel.org> Reported-by: Stefan Hellermann <stefan@the2masters.de> Tested-by: Stefan Hellermann <stefan@the2masters.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <stable@kernel.org> [2.6.34+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-26Merge branch 'master' into for-nextJiri Kosina1-14/+81
Fast-forwarded to current state of Linus' tree as there are patches to be applied for files that didn't exist on the old branch.
2011-04-14mm/page_alloc.c: silence build_all_zonelists() section mismatchPaul Mundt1-1/+1
The memory hotplug case involves calling to build_all_zonelists() which in turns calls in to setup_zone_pageset(). The latter is marked __meminit while build_all_zonelists() itself has no particular annotation. build_all_zonelists() is only handed a non-NULL pointer in the case of memory hotplug through an existing __meminit path, so the setup_zone_pageset() reference is always safe. The options as such are either to flag build_all_zonelists() as __ref (as per __build_all_zonelists()), or to simply discard the __meminit annotation from setup_zone_pageset(). Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-10mm: Fix section mismatch for setup_zone_pageset()Nikanth Karthikesan1-1/+1
build_all_zonelists() which is not __meminit, calls setup_zone_pageset(). Signed-off-by: Nikanth Karthikesan <knikanth@suse.de> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-31Fix common misspellingsLucas De Marchi1-2/+2
Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-24lib, arch: add filter argument to show_mem and fix private implementationsDavid Rientjes1-1/+1
Commit ddd588b5dd55 ("oom: suppress nodes that are not allowed from meminfo on oom kill") moved lib/show_mem.o out of lib/lib.a, which resulted in build warnings on all architectures that implement their own versions of show_mem(): lib/lib.a(show_mem.o): In function `show_mem': show_mem.c:(.text+0x1f4): multiple definition of `show_mem' arch/sparc/mm/built-in.o:(.text+0xd70): first defined here The fix is to remove __show_mem() and add its argument to show_mem() in all implementations to prevent this breakage. Architectures that implement their own show_mem() actually don't do anything with the argument yet, but they could be made to filter nodes that aren't allowed in the current context in the future just like the generic implementation. Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: James Bottomley <James.Bottomley@hansenpartnership.com> Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23memcg: add memcg sanity checks at allocating and freeing pagesDaisuke Nishimura1-2/+6
Add checks at allocating or freeing a page whether the page is used (iow, charged) from the view point of memcg. This check may be useful in debugging a problem and we did similar checks before the commit 52d4b9ac(memcg: allocate all page_cgroup at boot). This patch adds some overheads at allocating or freeing memory, so it's enabled only when CONFIG_DEBUG_VM is enabled. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22mm/page_alloc.c: use list_move() instead of list_del()/list_add() combinationKirill A. Shutemov1-3/+2
Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Rik van Riel <riel@redhat.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22mm: add __GFP_OTHER_NODE flagAndi Kleen1-1/+1
Add a new __GFP_OTHER_NODE flag to tell the low level numa statistics in zone_statistics() that an allocation is on behalf of another thread. This way the local and remote counters can be still correct, even when background daemons like khugepaged are changing memory mappings. This only affects the accounting, but I think it's worth doing that right to avoid confusing users. I first tried to just pass down the right node, but this required a lot of changes to pass down this parameter and at least one addition of a 10th argument to a 9 argument function. Using the flag is a lot less intrusive. Open: should be also used for migration? [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2011-03-22mm: compaction: Use async migration for __GFP_NO_KSWAPD and enforce no writebackAndrea Arcangeli1-1/+1
__GFP_NO_KSWAPD allocations are usually very expensive and not mandatory to succeed as they have graceful fallback. Waiting for I/O in those, tends to be overkill in terms of latencies, so we can reduce their latency by disabling sync migrate. Unfortunately, even with async migration it's still possible for the process to be blocked waiting for a request slot (e.g. get_request_wait in the block layer) when ->writepage is called. To prevent __GFP_NO_KSWAPD blocking, this patch prevents ->writepage being called on dirty page cache for asynchronous migration. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=31142 [mel@csn.ul.ie: Avoid writebacks for NFS, retry locked pages, use bool] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mel@csn.ul.ie> Cc: Arthur Marsh <arthur.marsh@internode.on.net> Cc: Clemens Ladisch <cladisch@googlemail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Reported-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Tested-by: Alex Villacis Lasso <avillaci@ceibo.fiec.espol.edu.ec> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22mm: batch-free pcp list if possibleNamhyung Kim1-0/+4
free_pcppages_bulk() frees pages from pcp lists in a round-robin fashion by keeping batch_free counter. But it doesn't need to spin if there is only one non-empty list. This can be checked by batch_free == MIGRATE_PCPTYPES. [akpm@linux-foundation.org: fix comment] Signed-off-by: Namhyung Kim <namhyung@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.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>
2011-03-22oom: suppress nodes that are not allowed from meminfo on page alloc failureDavid Rientjes1-3/+16
Displaying extremely verbose meminfo for all nodes on the system is overkill for page allocation failures when the context restricts that allocation to only a subset of nodes. We don't particularly care about the state of all nodes when some are not allowed in the current context, they can have an abundance of memory but we can't allocate from that part of memory. This patch suppresses disallowed nodes from the meminfo dump on a page allocation failure if the context requires it. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22oom: suppress show_mem() for many nodes in irq context on page alloc failureDavid Rientjes1-1/+16
When a page allocation failure occurs, show_mem() is called to dump the state of the VM so users may understand what happened to get into that condition. This output, however, can be extremely verbose. In irq context, it may result in significant delays that incur NMI watchdog timeouts when the machine is large (we use CONFIG_NODES_SHIFT > 8 here to define a "large" machine since the length of the show_mem() output is proportional to the number of possible nodes). This patch suppresses the show_mem() call in irq context when the kernel has CONFIG_NODES_SHIFT > 8. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-22oom: suppress nodes that are not allowed from meminfo on oom killDavid Rientjes1-1/+33
The oom killer is extremely verbose for machines with a large number of cpus and/or nodes. This verbosity can often be harmful if it causes other important messages to be scrolled from the kernel log and incurs a signicant time delay, specifically for kernels with CONFIG_NODES_SHIFT > 8. This patch causes only memory information to be displayed for nodes that are allowed by current's cpuset when dumping the VM state. Information for all other nodes is irrelevant to the oom condition; we don't care if there's an abundance of memory elsewhere if we can't access it. This only affects the behavior of dumping memory information when an oom is triggered. Other dumps, such as for sysrq+m, still display the unfiltered form when using the existing show_mem() interface. Additionally, the per-cpu pageset statistics are extremely verbose in oom killer output, so it is now suppressed. This removes nodes_weight(current->mems_allowed) * (1 + nr_cpus) lines from the oom killer output. Callers may use __show_mem(SHOW_MEM_FILTER_NODES) to filter disallowed nodes. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-17mm: PageBuddy and mapcount robustnessAndrea Arcangeli1-2/+2
Change the _mapcount value indicating PageBuddy from -2 to -128 for more robusteness against page_mapcount() undeflows. Use reset_page_mapcount instead of __ClearPageBuddy in bad_page to ignore the previous retval of PageBuddy(). Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-15Merge commit 'v2.6.38' into x86/mmIngo Molnar1-3/+2
Conflicts: arch/x86/mm/numa_64.c Merge reason: Resolve the conflict, update the branch to .38. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-02-26mm: Move early_node_map[] reverse scan helpers under HAVE_MEMBLOCKYinghai Lu1-32/+32
Heiko found recent memblock change triggers these warnings on s390: mm/page_alloc.c:3623:22: warning: 'last_active_region_index_in_nid' defined but not used mm/page_alloc.c:3638:22: warning: 'previous_active_region_index_in_nid' defined but not used Need to move those two function under HAVE_MEMBLOCK with its only user, find_memory_core_early(). -tj: Minor updates to description. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-25mm: fix dubious code in __count_immobile_pages()Namhyung Kim1-3/+2
When pfn_valid_within() failed 'iter' was incremented twice. Signed-off-by: Namhyung Kim <namhyung@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-24bootmem: Move __alloc_memory_core_early() to nobootmem.cYinghai Lu1-28/+0
Now that bootmem.c and nobootmem.c are separate, there's no reason to define __alloc_memory_core_early(), which is used only by nobootmem, inside #ifdef in page_alloc.c. Move it to nobootmem.c and make it static. This patch doesn't introduce any behavior change. -tj: Updated commit description. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-24bootmem: Move contig_page_data definition to bootmem.c/nobootmem.cYinghai Lu1-9/+0
Now that bootmem.c and nobootmem.c are separate, it's cleaner to define contig_page_data in each file than in page_alloc.c with #ifdef. Move it. This patch doesn't introduce any behavior change. -v2: According to Andrew, fixed the struct layout. -tj: Updated commit description. Signed-off-by: Yinghai Lu <yinghai@kernel.org> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2011-02-14Merge branch 'linus' into x86/bootmemIngo Molnar1-78/+138
Conflicts: arch/x86/mm/numa_64.c Merge reason: fix the conflict, update to latest -rc and pick up this dependent fix from Yinghai: e6d2e2b2b1e1: memblock: don't adjust size in memblock_find_base() Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-01-26mm: clear pages_scanned only if draining a pcp adds pages to the buddy allocatorDavid Rientjes1-2/+4
Commit 0e093d99763e ("writeback: do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone") uncovered a livelock in the page allocator that resulted in tasks infinitely looping trying to find memory and kswapd running at 100% cpu. The issue occurs because drain_all_pages() is called immediately following direct reclaim when no memory is freed and try_to_free_pages() returns non-zero because all zones in the zonelist do not have their all_unreclaimable flag set. When draining the per-cpu pagesets back to the buddy allocator for each zone, the zone->pages_scanned counter is cleared to avoid erroneously setting zone->all_unreclaimable later. The problem is that no pages may actually be drained and, thus, the unreclaimable logic never fails direct reclaim so the oom killer may be invoked. This apparently only manifested after wait_iff_congested() was introduced and the zone was full of anonymous memory that would not congest the backing store. The page allocator would infinitely loop if there were no other tasks waiting to be scheduled and clear zone->pages_scanned because of drain_all_pages() as the result of this change before kswapd could scan enough pages to trigger the reclaim logic. Additionally, with every loop of the page allocator and in the reclaim path, kswapd would be kicked and would end up running at 100% cpu. In this scenario, current and kswapd are all running continuously with kswapd incrementing zone->pages_scanned and current clearing it. The problem is even more pronounced when current swaps some of its memory to swap cache and the reclaimable logic then considers all active anonymous memory in the all_unreclaimable logic, which requires a much higher zone->pages_scanned value for try_to_free_pages() to return zero that is never attainable in this scenario. Before wait_iff_congested(), the page allocator would incur an unconditional timeout and allow kswapd to elevate zone->pages_scanned to a level that the oom killer would be called the next time it loops. The fix is to only attempt to drain pcp pages if there is actually a quantity to be drained. The unconditional clearing of zone->pages_scanned in free_pcppages_bulk() need not be changed since other callers already ensure that draining will occur. This patch ensures that free_pcppages_bulk() will actually free memory before calling into it from drain_all_pages() so zone->pages_scanned is only cleared if appropriate. Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-26mm: fix deferred congestion timeout if preferred zone is not allowedDavid Rientjes1-1/+11
Before 0e093d99763e ("writeback: do not sleep on the congestion queue if there are no congested BDIs or if significant congestion is not being encountered in the current zone"), preferred_zone was only used for NUMA statistics, to determine the zoneidx from which to allocate from given the type requested, and whether to utilize memory compaction. wait_iff_congested(), though, uses preferred_zone to determine if the congestion wait should be deferred because its dirty pages are backed by a congested bdi. This incorrectly defers the timeout and busy loops in the page allocator with various cond_resched() calls if preferred_zone is not allowed in the current context, usually consuming 100% of a cpu. This patch ensures preferred_zone is an allowed zone in the fastpath depending on whether current is constrained by its cpuset or nodes in its mempolicy (when the nodemask passed is non-NULL). This is correct since the fastpath allocation always passes ALLOC_CPUSET when trying to allocate memory. In the slowpath, this patch resets preferred_zone to the first zone of the allowed type when the allocation is not constrained by current's cpuset, i.e. it does not pass ALLOC_CPUSET. This patch also ensures preferred_zone is from the set of allowed nodes when called from within direct reclaim since allocations are always constrained by cpusets in this context (it is blockable). Both of these uses of cpuset_current_mems_allowed are protected by get_mems_allowed(). Signed-off-by: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13mm/page_alloc.c: don't cache `current' in a localAndrew Morton1-14/+10
It's old-fashioned and unneeded. akpm:/usr/src/25> size mm/page_alloc.o text data bss dec hex filename 39884 1241317 18808 1300009 13d629 mm/page_alloc.o (before) 39838 1241317 18808 1299963 13d5fb mm/page_alloc.o (after) Acked-by: David Rientjes <rientjes@google.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13mm/page_alloc.c: simplify calculation of combined index of adjacent buddy listsKyongHo Cho1-15/+10
The previous approach of calucation of combined index was page_idx & ~(1 << order)) but we have same result with page_idx & buddy_idx This reduces instructions slightly as well as enhances readability. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix used-unintialised warning] Signed-off-by: KyongHo Cho <pullip.cho@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-13thp: remove PG_buddyAndrea Arcangeli1-4/+3
PG_buddy can be converted to _mapcount == -2. So the PG_compound_lock can be added to page->flags without overflowing (because of the sparse section bits increasing) with CONFIG_X86_PAE=y and CONFIG_X86_PAT=y. This also has to move the memory hotplug code from _mapcount to lru.next to avoid any risk of clashes. We can't use lru.next for PG_buddy removal, but memory hotplug can use lru.next even more easily than the mapcount instead. 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>
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