- 15 Dec, 2009 2 commits
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KOSAKI Motohiro authored
If reclaim fails to make sufficient progress, the priority is raised. Once the priority is higher, kswapd starts waiting on congestion. However, if the zone is below the min watermark then kswapd needs to continue working without delay as there is a danger of an increased rate of GFP_ATOMIC allocation failure. This patch changes the conditions under which kswapd waits on congestion by only going to sleep if the min watermarks are being met. [mel@csn.ul.ie: add stats to track how relevant the logic is] [mel@csn.ul.ie: make kswapd only check its own zones and rename the relevant counters] Signed-off-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
Mel Gorman <mel@csn.ul.ie> 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>
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Mel Gorman authored
After kswapd balances all zones in a pgdat, it goes to sleep. In the event of no IO congestion, kswapd can go to sleep very shortly after the high watermark was reached. If there are a constant stream of allocations from parallel processes, it can mean that kswapd went to sleep too quickly and the high watermark is not being maintained for sufficient length time. This patch makes kswapd go to sleep as a two-stage process. It first tries to sleep for HZ/10. If it is woken up by another process or the high watermark is no longer met, it's considered a premature sleep and kswapd continues work. Otherwise it goes fully to sleep. This adds more counters to distinguish between fast and slow breaches of watermarks. A "fast" premature sleep is one where the low watermark was hit in a very short time after kswapd going to sleep. A "slow" premature sleep indicates that the high watermark was breached after a very short interval. Signed-off-by:
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- 29 Oct, 2009 1 commit
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Tejun Heo authored
This patch updates percpu related symbols under kernel/ and mm/ such that percpu symbols are unique and don't clash with local symbols. This serves two purposes of decreasing the possibility of global percpu symbol collision and allowing dropping per_cpu__ prefix from percpu symbols. * kernel/lockdep.c: s/lock_stats/cpu_lock_stats/ * kernel/sched.c: s/init_rq_rt/init_rt_rq_var/ (any better idea?) s/sched_group_cpus/sched_groups/ * kernel/softirq.c: s/ksoftirqd/run_ksoftirqd/a * kernel/softlockup.c: s/(*)_timestamp/softlockup_\1_ts/ s/watchdog_task/softlockup_watchdog/ s/timestamp/ts/ for local variables * kernel/time/timer_stats: s/lookup_lock/tstats_lookup_lock/ * mm/slab.c: s/reap_work/slab_reap_work/ s/reap_node/slab_reap_node/ * mm/vmstat.c: local variable changed to avoid collision with vmstat_work Partly based on Rusty Russell's "alloc_percpu: rename percpu vars which cause name clashes" patch. Signed-off-by:
Tejun Heo <tj@kernel.org> Acked-by:
(slab/vmstat) Christoph Lameter <cl@linux-foundation.org> Reviewed-by:
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- 22 Sep, 2009 3 commits
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KOSAKI Motohiro authored
If the system is running a heavy load of processes then concurrent reclaim can isolate a large number of pages from the LRU. /proc/vmstat and the output generated for an OOM do not show how many pages were isolated. This has been observed during process fork bomb testing (mstctl11 in LTP). This patch shows the information about isolated pages. Reproduced via: ----------------------- % ./hackbench 140 process 1000 => OOM occur active_anon:146 inactive_anon:0 isolated_anon:49245 active_file:79 inactive_file:18 isolated_file:113 unevictable:0 dirty:0 writeback:0 unstable:0 buffer:39 free:370 slab_reclaimable:309 slab_unreclaimable:5492 mapped:53 shmem:15 pagetables:28140 bounce:0 Signed-off-by:
Wu Fengguang <fengguang.wu@intel.com> Reviewed-by:
Minchan Kim <minchan.kim@gmail.com> Cc: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by:
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KOSAKI Motohiro authored
Recently we encountered OOM problems due to memory use of the GEM cache. Generally a large amuont of Shmem/Tmpfs pages tend to create a memory shortage problem. We often use the following calculation to determine the amount of shmem pages: shmem = NR_ACTIVE_ANON + NR_INACTIVE_ANON - NR_ANON_PAGES however the expression does not consider isolated and mlocked pages. This patch adds explicit accounting for pages used by shmem and tmpfs. Signed-off-by:
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KOSAKI Motohiro authored
The amount of memory allocated to kernel stacks can become significant and cause OOM conditions. However, we do not display the amount of memory consumed by stacks. Add code to display the amount of memory used for stacks in /proc/meminfo. Signed-off-by:
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- 17 Jun, 2009 5 commits
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Mel Gorman authored
On NUMA machines, the administrator can configure zone_reclaim_mode that is a more targetted form of direct reclaim. On machines with large NUMA distances for example, a zone_reclaim_mode defaults to 1 meaning that clean unmapped pages will be reclaimed if the zone watermarks are not being met. There is a heuristic that determines if the scan is worthwhile but it is possible that the heuristic will fail and the CPU gets tied up scanning uselessly. Detecting the situation requires some guesswork and experimentation so this patch adds a counter "zreclaim_failed" to /proc/vmstat. If during high CPU utilisation this counter is increasing rapidly, then the resolution to the problem may be to set /proc/sys/vm/zone_reclaim_mode to 0. [akpm@linux-foundation.org: name things consistently] Signed-off-by:
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KOSAKI Motohiro authored
Currently, nobody wants to turn UNEVICTABLE_LRU off. Thus this configurability is unnecessary. Signed-off-by:
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Wu Fengguang authored
The lru->nr_saved_scan's are not meaningful counters for even kernel developers. They typically are smaller than 32 and are always 0 for large lists. So remove them from /proc/zoneinfo. Hopefully this interface change won't break too many scripts. /proc/zoneinfo is too unstructured to be script friendly, and I wonder the affected scripts - if there are any - are still bleeding since the not long ago commit "vmscan: split LRU lists into anon & file sets", which also touched the "scanned" line :) If we are to re-export accumulated vmscan counts in the future, they can go to new lines in /proc/zoneinfo instead of the current form, or to /sys/devices/system/node/node0/meminfo? Signed-off-by:
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Wu Fengguang authored
The vmscan batching logic is twisting. Move it into a standalone function nr_scan_try_batch() and document it. No behavior change. Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by:
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Mel Gorman authored
ALLOC_WMARK_MIN, ALLOC_WMARK_LOW and ALLOC_WMARK_HIGH determin whether pages_min, pages_low or pages_high is used as the zone watermark when allocating the pages. Two branches in the allocator hotpath determine which watermark to use. This patch uses the flags as an array index into a watermark array that is indexed with WMARK_* defines accessed via helpers. All call sites that use zone->pages_* are updated to use the helpers for accessing the values and the array offsets for setting. Signed-off-by:
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- 18 May, 2009 1 commit
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Mel Gorman authored
pfn_valid() is meant to be able to tell if a given PFN has valid memmap associated with it or not. In FLATMEM, it is expected that holes always have valid memmap as long as there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed that a valid section has a memmap for the entire section. However, ARM and maybe other embedded architectures in the future free memmap backing holes to save memory on the assumption the memmap is never used. The page_zone linkages are then broken even though pfn_valid() returns true. A walker of the full memmap must then do this additional check to ensure the memmap they are looking at is sane by making sure the zone and PFN linkages are still valid. This is expensive, but walkers of the full memmap are extremely rare. This was caught before for FLATMEM and hacked around but it hits again for SPARSEMEM because the page_zone linkages can look ok where the PFN linkages are totally screwed. This looks like a hatchet job but the reality is that any clean solution would end up consumning all the memory saved by punching these unexpected holes in the memmap. For example, we tried marking the memmap within the section invalid but the section size exceeds the size of the hole in most cases so pfn_valid() starts returning false where valid memmap exists. Shrinking the size of the section would increase memory consumption offsetting the gains. This patch identifies when an architecture is punching unexpected holes in the memmap that the memory model cannot automatically detect and sets ARCH_HAS_HOLES_MEMORYMODEL. At the moment, this is restricted to EP93xx which is the model sub-architecture this has been reported on but may expand later. When set, walkers of the full memmap must call memmap_valid_within() for each PFN and passing in what it expects the page and zone to be for that PFN. If it finds the linkages to be broken, it assumes the memmap is invalid for that PFN. Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk>
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- 03 Apr, 2009 1 commit
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Anton Blanchard authored
Even though vmstat_work is marked deferrable, there are still benefits to aligning it. For certain applications we want to keep OS jitter as low as possible and aligning timers and work so they occur together can reduce their overall impact. Signed-off-by:
Anton Blanchard <anton@samba.org> Signed-off-by:
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- 01 Apr, 2009 1 commit
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KOSAKI Motohiro authored
Impact: cleanup In almost cases, for_each_zone() is used with populated_zone(). It's because almost function doesn't need memoryless node information. Therefore, for_each_populated_zone() can help to make code simplify. This patch has no functional change. [akpm@linux-foundation.org: small cleanup] Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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- 30 Mar, 2009 1 commit
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Rusty Russell authored
Impact: cleanup Time to clean up remaining laggards using the old cpu_ functions. Signed-off-by:Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@suse.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Trond.Myklebust@netapp.com
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- 31 Dec, 2008 1 commit
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Rusty Russell authored
Impact: Use new API Convert kernel mm functions to use struct cpumask. We skip include/linux/percpu.h and mm/allocpercpu.c, which are in flux. Signed-off-by:
Mike Travis <travis@sgi.com> Reviewed-by:
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- 23 Oct, 2008 4 commits
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Alexey Dobriyan authored
Signed-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Acked-by:
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Alexey Dobriyan authored
Signed-off-by:
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Alexey Dobriyan authored
Signed-off-by: -
Alexey Dobriyan authored
Signed-off-by:
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- 20 Oct, 2008 7 commits
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Lee Schermerhorn authored
Allow free of mlock()ed pages. This shouldn't happen, but during developement, it occasionally did. This patch allows us to survive that condition, while keeping the statistics and events correct for debug. Signed-off-by:
Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by:
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Nick Piggin authored
Add NR_MLOCK zone page state, which provides a (conservative) count of mlocked pages (actually, the number of mlocked pages moved off the LRU). Reworked by lts to fit in with the modified mlock page support in the Reclaim Scalability series. [kosaki.motohiro@jp.fujitsu.com: fix incorrect Mlocked field of /proc/meminfo] [lee.schermerhorn@hp.com: mlocked-pages: add event counting with statistics] Signed-off-by:
Nick Piggin <npiggin@suse.de> Signed-off-by:
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Lee Schermerhorn authored
Report unevictable pages per zone and system wide. Kosaki Motohiro added support for memory controller unevictable statistics. [riel@redhat.com: fix printk in show_free_areas()] [akpm@linux-foundation.org: fix units in /proc/vmstats] Signed-off-by:
Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Signed-off-by:
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Lee Schermerhorn authored
Fix to unevictable-lru-page-statistics.patch Add unevictable lru infrastructure vm events to the statistics patch. Rename the "NORECL_" and "noreclaim_" symbols and text strings to "UNEVICTABLE_" and "unevictable_", respectively. Currently, both the infrastructure and the mlocked pages event are added by a single patch later in the series. This makes it difficult to add or rework the incremental patches. The events actually "belong" with the stats, so pull them up to here. Also, restore the event counting to putback_lru_page(). This was removed from previous patch in series where it was "misplaced". The actual events weren't defined that early. Signed-off-by:
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Rik van Riel authored
We avoid evicting and scanning anonymous pages for the most part, but under some workloads we can end up with most of memory filled with anonymous pages. At that point, we suddenly need to clear the referenced bits on all of memory, which can take ages on very large memory systems. We can reduce the maximum number of pages that need to be scanned by not taking the referenced state into account when deactivating an anonymous page. After all, every anonymous page starts out referenced, so why check? If an anonymous page gets referenced again before it reaches the end of the inactive list, we move it back to the active list. To keep the maximum amount of necessary work reasonable, we scale the active to inactive ratio with the size of memory, using the formula active:inactive ratio = sqrt(memory in GB * 10). Kswapd CPU use now seems to scale by the amount of pageout bandwidth, instead of by the amount of memory present in the system. [kamezawa.hiroyu@jp.fujitsu.com: fix OOM with memcg] [kamezawa.hiroyu@jp.fujitsu.com: memcg: lru scan fix] Signed-off-by:
KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by:
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Rik van Riel authored
Split the LRU lists in two, one set for pages that are backed by real file systems ("file") and one for pages that are backed by memory and swap ("anon"). The latter includes tmpfs. The advantage of doing this is that the VM will not have to scan over lots of anonymous pages (which we generally do not want to swap out), just to find the page cache pages that it should evict. This patch has the infrastructure and a basic policy to balance how much we scan the anon lists and how much we scan the file lists. The big policy changes are in separate patches. [lee.schermerhorn@hp.com: collect lru meminfo statistics from correct offset] [kosaki.motohiro@jp.fujitsu.com: prevent incorrect oom under split_lru] [kosaki.motohiro@jp.fujitsu.com: fix pagevec_move_tail() doesn't treat unevictable page] [hugh@veritas.com: memcg swapbacked pages active] [hugh@veritas.com: splitlru: BDI_CAP_SWAP_BACKED] [akpm@linux-foundation.org: fix /proc/vmstat units] [nishimura@mxp.nes.nec.co.jp: memcg: fix handling of shmem migration] [kosaki.motohiro@jp.fujitsu.com: adjust Quicklists field of /proc/meminfo] [kosaki.motohiro@jp.fujitsu.com: fix style issue of get_scan_ratio()] Signed-off-by:Hugh Dickins <hugh@veritas.com> Signed-off-by:
Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by:
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Christoph Lameter authored
Currently we are defining explicit variables for the inactive and active list. An indexed array can be more generic and avoid repeating similar code in several places in the reclaim code. We are saving a few bytes in terms of code size: Before: text data bss dec hex filename 4097753 573120 4092484 8763357 85b7dd vmlinux After: text data bss dec hex filename 4097729 573120 4092484 8763333 85b7c5 vmlinux Having an easy way to add new lru lists may ease future work on the reclaim code. Signed-off-by:
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- 27 Aug, 2008 1 commit
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Mel Gorman authored
Ordinarily, memory holes in flatmem still have a valid memmap and is safe to use. However, an architecture (ARM) frees up the memmap backing memory holes on the assumption it is never used. /proc/pagetypeinfo reads the whole range of pages in a zone believing that the memmap is valid and that pfn_valid will return false if it is not. On ARM, freeing the memmap breaks the page->zone linkages even though pfn_valid() returns true and the kernel can oops shortly afterwards due to accessing a bogus struct zone *. This patch lets architectures say when FLATMEM can have holes in the memmap. Rather than an expensive check for valid memory, /proc/pagetypeinfo will confirm that the page linkages are still valid by checking page->zone is still the expected zone. The lookup of page_zone is safe as there is a limited range of memory that is accessed when calling page_zone. Even if page_zone happens to return the correct zone, the impact is that the counters in /proc/pagetypeinfo are slightly off but fragmentation monitoring is unlikely to be relevant on an embedded system. Reported-by:
H Hartley Sweeten <hsweeten@visionengravers.com> Signed-off-by:
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- 24 Jul, 2008 1 commit
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Adrian Bunk authored
This patch adds proper extern declarations for five variables in include/linux/vmstat.h Signed-off-by:
Adrian Bunk <bunk@kernel.org> Signed-off-by:
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- 23 May, 2008 1 commit
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Mike Travis authored
Change references from for_each_cpu_mask to for_each_cpu_mask_nr where appropriate Reviewed-by:
Paul Jackson <pj@sgi.com> Reviewed-by:
Christoph Lameter <clameter@sgi.com> Signed-off-by:
Ingo Molnar <mingo@elte.hu> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de>
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- 13 May, 2008 1 commit
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KOSAKI Motohiro authored
When accessing cpu_online_map, we should prevent dynamic changing of cpu_online_map by get_online_cpus(). Unfortunately, all_vm_events() doesn't do that. Signed-off-by:
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- 30 Apr, 2008 2 commits
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Miklos Szeredi authored
Fuse will use temporary buffers to write back dirty data from memory mappings (normal writes are done synchronously). This is needed, because there cannot be any guarantee about the time in which a write will complete. By using temporary buffers, from the MM's point if view the page is written back immediately. If the writeout was due to memory pressure, this effectively migrates data from a full zone to a less full zone. This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used as temporary buffers. [Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP] Signed-off-by:
Miklos Szeredi <mszeredi@suse.cz> Cc: Christoph Lameter <clameter@sgi.com> Signed-off-by:
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KOSAKI Motohiro authored
on memoryless node, /proc/pagetypeinfo is displayed slightly funny output. this patch fix it. output example (header is outputed, but no data is outputed) -------------------------------------------------------------- Page block order: 14 Pages per block: 16384 Free pages count per migrate type at order 0 1 2 3 4 5 \ 6 7 8 9 10 11 12 13 14 15 16 Number of blocks type Unmovable Reclaimable Movable Reserve Isolate Page block order: 14 Pages per block: 16384 Free pages count per migrate type at order 0 1 2 3 4 5 \ 6 7 8 9 10 11 12 13 14 15 16 Signed-off-by:
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- 28 Apr, 2008 3 commits
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Dimitri Sivanich authored
We've found that it can take quite a bit of time (100's of usec) to get through the zone loop in refresh_cpu_vm_stats(). Adding a cond_resched() to allow other threads to run in the non-preemptive case. Signed-off-by:
Dimitri Sivanich <sivanich@sgi.com> Acked-by:
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Adam Litke authored
Allocating huge pages directly from the buddy allocator is not guaranteed to succeed. Success depends on several factors (such as the amount of physical memory available and the level of fragmentation). With the addition of dynamic hugetlb pool resizing, allocations can occur much more frequently. For these reasons it is desirable to keep track of huge page allocation successes and failures. Add two new vmstat entries to track huge page allocations that succeed and fail. The presence of the two entries is contingent upon CONFIG_HUGETLB_PAGE being enabled. [akpm@linux-foundation.org: reduced ifdeffery] Signed-off-by:
Adam Litke <agl@us.ibm.com> Signed-off-by:
Eric Munson <ebmunson@us.ibm.com> Tested-by:
Andy Whitcroft <apw@shadowen.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
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Mel Gorman authored
On NUMA, zone_statistics() is used to record events like numa hit, miss and foreign. It assumes that the first zone in a zonelist is the preferred zone. When multiple zonelists are replaced by one that is filtered, this is no longer the case. This patch records what the preferred zone is rather than assuming the first zone in the zonelist is it. This simplifies the reading of later patches in this set. Signed-off-by:
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- 16 Apr, 2008 1 commit
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KOSAKI Motohiro authored
In a5d76b54 (memory unplug: page isolation by KAMEZAWA Hiroyuki), "isolate" migratetype added. but unfortunately, it doesn't treat /proc/pagetypeinfo display logic. this patch add "Isolate" to pagetype name field. /proc/pagetype before: ------------------------------------------------------------------------------------------------------------------------ Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 Node 0, zone DMA, type Unmovable 1 2 2 2 1 2 2 1 1 0 0 Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone DMA, type Movable 2 3 3 1 3 3 2 0 0 0 0 Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone DMA, type <NULL> 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone Normal, type Unmovable 1 9 7 4 1 1 1 1 0 0 0 Node 0, zone Normal, type Reclaimable 5 2 0 0 1 1 0 0 0 1 0 Node 0, zone Normal, type Movable 0 1 1 0 0 0 1 0 0 1 60 Node 0, zone Normal, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone Normal, type <NULL> 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone HighMem, type Unmovable 0 0 1 1 1 0 1 1 2 2 0 Node 0, zone HighMem, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone HighMem, type Movable 236 62 6 2 2 1 1 0 1 1 16 Node 0, zone HighMem, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone HighMem, type <NULL> 0 0 0 0 0 0 0 0 0 0 0 Number of blocks type Unmovable Reclaimable Movable Reserve <NULL> Node 0, zone DMA 1 0 2 1 0 Node 0, zone Normal 10 40 169 1 0 Node 0, zone HighMem 2 0 283 1 0 after: ------------------------------------------------------------------------------------------------------------------------ Free pages count per migrate type at order 0 1 2 3 4 5 6 7 8 9 10 Node 0, zone DMA, type Unmovable 1 2 2 2 1 2 2 1 1 0 0 Node 0, zone DMA, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone DMA, type Movable 2 3 3 1 3 3 2 0 0 0 0 Node 0, zone DMA, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone DMA, type Isolate 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone Normal, type Unmovable 0 2 1 1 0 1 0 0 0 0 0 Node 0, zone Normal, type Reclaimable 1 1 1 1 1 0 1 1 1 0 0 Node 0, zone Normal, type Movable 0 1 1 1 0 1 0 1 0 0 196 Node 0, zone Normal, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone Normal, type Isolate 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone HighMem, type Unmovable 0 1 0 0 0 1 1 1 2 2 0 Node 0, zone HighMem, type Reclaimable 0 0 0 0 0 0 0 0 0 0 0 Node 0, zone HighMem, type Movable 1 0 1 1 0 0 0 0 1 0 200 Node 0, zone HighMem, type Reserve 0 0 0 0 0 0 0 0 0 0 1 Node 0, zone HighMem, type Isolate 0 0 0 0 0 0 0 0 0 0 0 Number of blocks type Unmovable Reclaimable Movable Reserve Isolate Node 0, zone DMA 1 0 2 1 0 Node 0, zone Normal 8 4 207 1 0 Node 0, zone HighMem 2 0 283 1 0 Signed-off-by:
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- 05 Feb, 2008 3 commits
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Christoph Lameter authored
Remove the prefetch logic in order to avoid touching impossible per cpu areas. Signed-off-by:
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Christoph Lameter authored
We have repeatedly discussed if the cold pages still have a point. There is one way to join the two lists: Use a single list and put the cold pages at the end and the hot pages at the beginning. That way a single list can serve for both types of allocations. The discussion of the RFC for this and Mel's measurements indicate that there may not be too much of a point left to having separate lists for hot and cold pages (see http://marc.info/?t=119492914200001&r=1&w=2 ). Signed-off-by:
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Christoph Lameter authored
1. Add comments explaining how the function can be called. 2. Collect global diffs in a local array and only spill them once into the global counters when the zone scan is finished. This means that we only touch each global counter once instead of each time we fold cpu counters into zone counters. Signed-off-by:
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