summaryrefslogtreecommitdiffstats
path: root/mm
Commit message (Collapse)AuthorAgeFilesLines
* mm: vmscan: correctly check if reclaimer should schedule during shrink_slabMinchan Kim2011-05-251-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It has been reported on some laptops that kswapd is consuming large amounts of CPU and not being scheduled when SLUB is enabled during large amounts of file copying. It is expected that this is due to kswapd missing every cond_resched() point because; shrink_page_list() calls cond_resched() if inactive pages were isolated which in turn may not happen if all_unreclaimable is set in shrink_zones(). If for whatver reason, all_unreclaimable is set on all zones, we can miss calling cond_resched(). balance_pgdat() only calls cond_resched if the zones are not balanced. For a high-order allocation that is balanced, it checks order-0 again. During that window, order-0 might have become unbalanced so it loops again for order-0 and returns that it was reclaiming for order-0 to kswapd(). It can then find that a caller has rewoken kswapd for a high-order and re-enters balance_pgdat() without ever calling cond_resched(). shrink_slab only calls cond_resched() if we are reclaiming slab pages. If there are a large number of direct reclaimers, the shrinker_rwsem can be contended and prevent kswapd calling cond_resched(). This patch modifies the shrink_slab() case. If the semaphore is contended, the caller will still check cond_resched(). After each successful call into a shrinker, the check for cond_resched() remains in case one shrinker is particularly slow. [mgorman@suse.de: preserve call to cond_resched after each call into shrinker] Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Colin King <colin.king@canonical.com> Cc: Raghavendra D Prabhu <raghu.prabhu13@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Chris Mason <chris.mason@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@kernel.org> [2.6.38+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm: vmscan: correct use of pgdat_balanced in sleeping_prematurelyJohannes Weiner2011-05-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a few reports of people experiencing hangs when copying large amounts of data with kswapd using a large amount of CPU which appear to be due to recent reclaim changes. SLUB using high orders is the trigger but not the root cause as SLUB has been using high orders for a while. The root cause was bugs introduced into reclaim which are addressed by the following two patches. Patch 1 corrects logic introduced by commit 1741c877 ("mm: kswapd: keep kswapd awake for high-order allocations until a percentage of the node is balanced") to allow kswapd to go to sleep when balanced for high orders. Patch 2 notes that it is possible for kswapd to miss every cond_resched() and updates shrink_slab() so it'll at least reach that scheduling point. Chris Wood reports that these two patches in isolation are sufficient to prevent the system hanging. AFAIK, they should also resolve similar hangs experienced by James Bottomley. This patch: Johannes Weiner poined out that the logic in commit 1741c877 ("mm: kswapd: keep kswapd awake for high-order allocations until a percentage of the node is balanced") is backwards. Instead of allowing kswapd to go to sleep when balancing for high order allocations, it keeps it kswapd running uselessly. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Tested-by: Colin King <colin.king@canonical.com> Cc: Raghavendra D Prabhu <raghu.prabhu13@gmail.com> Cc: Jan Kara <jack@suse.cz> Cc: Chris Mason <chris.mason@oracle.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Cc: <stable@kernel.org> [2.6.38+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* slub: Fix double bit unlock in debug modeChristoph Lameter2011-05-251-1/+2
| | | | | | | | | | | | | | | | | | | | | | | Commit 442b06bcea23 ("slub: Remove node check in slab_free") added a call to deactivate_slab() in the debug case in __slab_alloc(), which unlocks the current slab used for allocation. Going to the label 'unlock_out' then does it again. Also, in the debug case we do not need all the other processing that the 'unlock_out' path does. We always fall back to the slow path in the debug case. So the tid update is useless. Similarly, ALLOC_SLOWPATH would just be incremented for all allocations. Also a pretty useless thing. So simply restore irq flags and return the object. Signed-off-by: Christoph Lameter <cl@linux.com> Reported-and-bisected-by: James Morris <jmorris@namei.org> Reported-by: Ingo Molnar <mingo@elte.hu> Reported-by: Jens Axboe <jaxboe@fusionio.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6Linus Torvalds2011-05-241-7/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (29 commits) [S390] cpu hotplug: fix external interrupt subclass mask handling [S390] oprofile: dont access lowcore [S390] oprofile: add missing irq stats counter [S390] Ignore sendmmsg system call note wired up warning [S390] s390,oprofile: fix compile error for !CONFIG_SMP [S390] s390,oprofile: fix alert counter increment [S390] Remove unused includes in process.c [S390] get CPC image name [S390] sclp: event buffer dissection [S390] chsc: process channel-path-availability information [S390] refactor page table functions for better pgste support [S390] merge page_test_dirty and page_clear_dirty [S390] qdio: prevent compile warning [S390] sclp: remove unnecessary sendmask check [S390] convert old cpumask API into new one [S390] pfault: cleanup code [S390] pfault: cpu hotplug vs missing completion interrupts [S390] smp: add __noreturn attribute to cpu_die() [S390] percpu: implement arch specific irqsafe_cpu_ops [S390] vdso: disable gcov profiling ...
| * [S390] merge page_test_dirty and page_clear_dirtyMartin Schwidefsky2011-05-231-7/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The page_clear_dirty primitive always sets the default storage key which resets the access control bits and the fetch protection bit. That will surprise a KVM guest that sets non-zero access control bits or the fetch protection bit. Merge page_test_dirty and page_clear_dirty back to a single function and only clear the dirty bit from the storage key. In addition move the function page_test_and_clear_dirty and page_test_and_clear_young to page.h where they belong. This requires to change the parameter from a struct page * to a page frame number. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* | Merge branch 'for-2.6.40' of ↵Linus Torvalds2011-05-241-2/+4
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-2.6.40' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: Unify input section names percpu: Avoid extra NOP in percpu_cmpxchg16b_double percpu: Cast away printk format warning percpu: Always align percpu output section to PAGE_SIZE Fix up fairly trivial conflict in arch/x86/include/asm/percpu.h as per Tejun
| * \ Merge branch 'fixes-2.6.39' into for-2.6.40Tejun Heo2011-05-248-18/+21
| |\ \
| | * | percpu: Cast away printk format warningMike Frysinger2011-03-281-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On 32-bit systems which don't happen to implicitly define or cast VMALLOC_START and/or VMALLOC_END to long in their arch headers, the printk in the percpu code will cause a warning to be emitted: mm/percpu.c: In function 'pcpu_embed_first_chunk': mm/percpu.c:1648: warning: format '%lx' expects type 'long unsigned int', but argument 3 has type 'unsigned int' So add an explicit cast to unsigned long here. Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Tejun Heo <tj@kernel.org>
| * | | percpu: Always align percpu output section to PAGE_SIZETejun Heo2011-03-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Percpu allocator honors alignment request upto PAGE_SIZE and both the percpu addresses in the percpu address space and the translated kernel addresses should be aligned accordingly. The calculation of the former depends on the alignment of percpu output section in the kernel image. The linker script macros PERCPU_VADDR() and PERCPU() are used to define this output section and the latter takes @align parameter. Several architectures are using @align smaller than PAGE_SIZE breaking percpu memory alignment. This patch removes @align parameter from PERCPU(), renames it to PERCPU_SECTION() and makes it always align to PAGE_SIZE. While at it, add PCPU_SETUP_BUG_ON() checks such that alignment problems are reliably detected and remove percpu alignment comment recently added in workqueue.c as the condition would trigger BUG way before reaching there. For um, this patch raises the alignment of percpu area. As the area is in .init, there shouldn't be any noticeable difference. This problem was discovered by David Howells while debugging boot failure on mn10300. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Mike Frysinger <vapier@gentoo.org> Cc: uclinux-dist-devel@blackfin.uclinux.org Cc: David Howells <dhowells@redhat.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: user-mode-linux-devel@lists.sourceforge.net
* | | | Merge branch 'for-linus' of ↵Linus Torvalds2011-05-231-100/+65
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Deal with hyperthetical case of PAGE_SIZE > 2M slub: Remove node check in slab_free slub: avoid label inside conditional slub: Make CONFIG_DEBUG_PAGE_ALLOC work with new fastpath slub: Avoid warning for !CONFIG_SLUB_DEBUG slub: Remove CONFIG_CMPXCHG_LOCAL ifdeffery slub: Move debug handlign in __slab_free slub: Move node determination out of hotpath slub: Eliminate repeated use of c->page through a new page variable slub: get_map() function to establish map of free objects in a slab slub: Use NUMA_NO_NODE in get_partial slub: Fix a typo in config name
| * \ \ \ Merge branch 'slab/next' into for-linusPekka Enberg2011-05-231-100/+65
| |\ \ \ \ | | |_|_|/ | |/| | | | | | | | | | | | | Conflicts: mm/slub.c
| | * | | slub: Remove node check in slab_freeChristoph Lameter2011-05-211-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can set the page pointing in the percpu structure to NULL to have the same effect as setting c->node to NUMA_NO_NODE. Gets rid of one check in slab_free() that was only used for forcing the slab_free to the slowpath for debugging. We still need to set c->node to NUMA_NO_NODE to force the slab_alloc() fastpath to the slowpath in case of debugging. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: avoid label inside conditionalDavid Rientjes2011-05-171-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Jumping to a label inside a conditional is considered poor style, especially considering the current organization of __slab_alloc(). This removes the 'load_from_page' label and just duplicates the three lines of code that it uses: c->node = page_to_nid(page); c->page = page; goto load_freelist; since it's probably not worth making this a separate helper function. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Make CONFIG_DEBUG_PAGE_ALLOC work with new fastpathChristoph Lameter2011-05-171-1/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fastpath can do a speculative access to a page that CONFIG_DEBUG_PAGE_ALLOC may have marked as invalid to retrieve the pointer to the next free object. Use probe_kernel_read in that case in order not to cause a page fault. Cc: <stable@kernel.org> # 38.x Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Avoid warning for !CONFIG_SLUB_DEBUGChristoph Lameter2011-05-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the #ifdef so that get_map is only defined if CONFIG_SLUB_DEBUG is defined. Reported-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Remove CONFIG_CMPXCHG_LOCAL ifdefferyChristoph Lameter2011-05-071-56/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove the #ifdefs. This means that the irqsafe_cpu_cmpxchg_double() is used everywhere. There may be performance implications since: A. We now have to manage a transaction ID for all arches B. The interrupt holdoff for arches not supporting CONFIG_CMPXCHG_LOCAL is reduced to a very short irqoff section. There are no multiple irqoff/irqon sequences as a result of this change. Even in the fallback case we only have to do one disable and enable like before. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Move debug handlign in __slab_freeChristoph Lameter2011-04-171-9/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Its easier to read if its with the check for debugging flags. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Move node determination out of hotpathChristoph Lameter2011-04-171-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the node does not change then there is no need to recalculate the node from the page struct. So move the node determination into the places where we acquire a new slab page. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Eliminate repeated use of c->page through a new page variableChristoph Lameter2011-04-171-19/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __slab_alloc is full of "c->page" repeats. Lets just use one local variable named "page" for this. Also avoids the need to a have another variable called "new". Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: get_map() function to establish map of free objects in a slabChristoph Lameter2011-04-171-12/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bit map of free objects in a slab page is determined in various functions if debugging is enabled. Provide a common function for that purpose. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Use NUMA_NO_NODE in get_partialChristoph Lameter2011-04-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A -1 was leftover during the conversion. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: Fix a typo in config nameLi Zefan2011-04-121-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's no config named SLAB_DEBUG, and it should be a typo of SLUB_DEBUG. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
* | | | | Merge branch 'for-linus' of ↵Linus Torvalds2011-05-232-2/+2
|\ \ \ \ \ | |/ / / / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * | | | Merge branch 'master' into for-nextJiri Kosina2011-04-2645-1359/+2123
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | 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.
| * | | | | treewide: remove extra semicolonsJustin P. Mattock2011-04-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
| * | | | | mm: Fix section mismatch for setup_zone_pageset()Nikanth Karthikesan2011-04-101-1/+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>
* | | | | | tmpfs: fix highmem swapoff crash regressionHugh Dickins2011-05-201-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 778dd893ae78 ("tmpfs: fix race between umount and swapoff") forgot the new rules for strict atomic kmap nesting, causing WARNING: at arch/x86/mm/highmem_32.c:81 from __kunmap_atomic(), then BUG: unable to handle kernel paging request at fffb9000 from shmem_swp_set() when shmem_unuse_inode() is handling swapoff with highmem in use. My disgrace again. See https://bugzilla.kernel.org/show_bug.cgi?id=35352 Reported-by: Witold Baryluk <baryluk@smp.if.uj.edu.pl> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | sanitize <linux/prefetch.h> usageLinus Torvalds2011-05-204-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | | | | Merge branch 'for-linus' of ↵Linus Torvalds2011-05-191-2/+5
|\ \ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux-2.6-cm: kmemleak: Initialise kmemleak after debug_objects_mem_init() kmemleak: Select DEBUG_FS unconditionally in DEBUG_KMEMLEAK kmemleak: Do not return a pointer to an object that kmemleak did not get
| * | | | | | kmemleak: Do not return a pointer to an object that kmemleak did not getCatalin Marinas2011-05-191-2/+5
| | |/ / / / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The kmemleak_seq_next() function tries to get an object (and increment its use count) before returning it. If it could not get the last object during list traversal (because it may have been freed), the function should return NULL rather than a pointer to such object that it did not get. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reported-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Cc: <stable@kernel.org>
* | | | | | memcg: fix zone congestionKAMEZAWA Hiroyuki2011-05-181-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ZONE_CONGESTED should be a state of global memory reclaim. If not, a busy memcg sets this and give unnecessary throttoling in wait_iff_congested() against memory recalim in other contexts. This makes system performance bad. I'll think about "memcg is congested!" flag is required or not, later. But this fix is required first. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Ying Han <yinghan@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | mm: fix kernel-doc warning in page_alloc.cRandy Dunlap2011-05-161-0/+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>
* | | | | | tmpfs: fix race between swapoff and writepageHugh Dickins2011-05-141-6/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Shame on me! Commit b1dea800ac39 "tmpfs: fix race between umount and writepage" fixed the advertized race, but introduced another: as even its comment makes clear, we cannot safely rely on a peek at list_empty() while holding no lock - until info->swapped is set, shmem_unuse_inode() may delete any formerly-swapped inode from the shmem_swaplist, which in this case would leave a swap area impossible to swapoff. Although I don't relish taking the mutex every time, I don't care much for the alternatives either; and at least the peek at list_empty() in shmem_evict_inode() (a hotter path since most inodes would never have been swapped) remains safe, because we already truncated the whole file. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | tmpfs: fix spurious ENOSPC when racing with unswapHugh Dickins2011-05-111-10/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Testing the shmem_swaplist replacements for igrab() revealed another bug: writes to /dev/loop0 on a tmpfs file which fills its filesystem were sometimes failing with "Buffer I/O error"s. These came from ENOSPC failures of shmem_getpage(), when racing with swapoff: the same could happen when racing with another shmem_getpage(), pulling the page in from swap in between our find_lock_page() and our taking the info->lock (though not in the single-threaded loop case). This is unacceptable, and surprising that I've not noticed it before: it dates back many years, but (presumably) was made a lot easier to reproduce in 2.6.36, which sited a page preallocation in the race window. Fix it by rechecking the page cache before settling on an ENOSPC error. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | tmpfs: fix race between umount and swapoffHugh Dickins2011-05-111-45/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The use of igrab() in swapoff's shmem_unuse_inode() is just as vulnerable to umount as that in shmem_writepage(). Fix this instance by extending the protection of shmem_swaplist_mutex right across shmem_unuse_inode(): while it's on the list, the inode cannot be evicted (and the filesystem cannot be unmounted) without shmem_evict_inode() taking that mutex to remove it from the list. But since shmem_writepage() might take that mutex, we should avoid making memory allocations or memcg charges while holding it: prepare them at the outer level in shmem_unuse(). When mem_cgroup_cache_charge() was originally placed, we didn't know until that point that the page from swap was actually a shmem page; but nowadays it's noted in the swap_map, so we're safe to charge upfront. For the radix_tree, do as is done in shmem_getpage(): preload upfront, but don't pin to the cpu; so we make a habit of refreshing the node pool, but might dip into GFP_NOWAIT reserves on occasion if subsequently preempted. With the allocation and charge moved out from shmem_unuse_inode(), we can also hold index map and info->lock over from finding the entry. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | tmpfs: fix race between umount and writepageHugh Dickins2011-05-111-11/+20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Konstanin Khlebnikov reports that a dangerous race between umount and shmem_writepage can be reproduced by this script: for i in {1..300} ; do mkdir $i while true ; do mount -t tmpfs none $i dd if=/dev/zero of=$i/test bs=1M count=$(($RANDOM % 100)) umount $i done & done on a 6xCPU node with 8Gb RAM: kernel very unstable after this accident. =) Kernel log: VFS: Busy inodes after unmount of tmpfs. Self-destruct in 5 seconds. Have a nice day... WARNING: at lib/list_debug.c:53 __list_del_entry+0x8d/0x98() list_del corruption. prev->next should be ffff880222fdaac8, but was (null) Pid: 11222, comm: mount.tmpfs Not tainted 2.6.39-rc2+ #4 Call Trace: warn_slowpath_common+0x80/0x98 warn_slowpath_fmt+0x41/0x43 __list_del_entry+0x8d/0x98 evict+0x50/0x113 iput+0x138/0x141 ... BUG: unable to handle kernel paging request at ffffffffffffffff IP: shmem_free_blocks+0x18/0x4c Pid: 10422, comm: dd Tainted: G W 2.6.39-rc2+ #4 Call Trace: shmem_recalc_inode+0x61/0x66 shmem_writepage+0xba/0x1dc pageout+0x13c/0x24c shrink_page_list+0x28e/0x4be shrink_inactive_list+0x21f/0x382 ... shmem_writepage() calls igrab() on the inode for the page which came from page reclaim, to add it later into shmem_swaplist for swapoff operation. This igrab() can race with super-block deactivating process: shrink_inactive_list() deactivate_super() pageout() tmpfs_fs_type->kill_sb() shmem_writepage() kill_litter_super() generic_shutdown_super() evict_inodes() igrab() atomic_read(&inode->i_count) skip-inode iput() if (!list_empty(&sb->s_inodes)) printk("VFS: Busy inodes after... This igrap-iput pair was added in commit 1b1b32f2c6f6 "tmpfs: fix shmem_swaplist races" based on incorrect assumptions: igrab() protects the inode from concurrent eviction by deletion, but it does nothing to protect it from concurrent unmounting, which goes ahead despite the raised i_count. So this use of igrab() was wrong all along, but the race made much worse in 2.6.37 when commit 63997e98a3be "split invalidate_inodes()" replaced two attempts at invalidate_inodes() by a single evict_inodes(). Konstantin posted a plausible patch, raising sb->s_active too: I'm unsure whether it was correct or not; but burnt once by igrab(), I am sure that we don't want to rely more deeply upon externals here. Fix it by adding the inode to shmem_swaplist earlier, while the page lock on page in page cache still secures the inode against eviction, without artifically raising i_count. It was originally added later because shmem_unuse_inode() is liable to remove an inode from the list while it's unswapped; but we can guard against that by taking spinlock before dropping mutex. Reported-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Signed-off-by: Hugh Dickins <hughd@google.com> Tested-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | memcg: allocate memory cgroup structures in local nodesAndi Kleen2011-05-111-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit dde79e005a769 ("page_cgroup: reduce allocation overhead for page_cgroup array for CONFIG_SPARSEMEM") added a regression that the memory cgroup data structures all end up in node 0 because the first attempt at allocating them would not pass in a node hint. Since the initialization runs on CPU #0 it would all end up node 0. This is a problem on large memory systems, where node 0 would lose a lot of memory. Change the alloc_pages_exact() to alloc_pages_exact_nid(). This will still fall back to other nodes if not enough memory is available. [ RED-PEN: right now it would fall back first before trying vmalloc_node. Probably not the best strategy ... But I left it like that for now. ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Reported-by: Doug Nelson Cc: David Rientjes <rientjes@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Hansen <dave@linux.vnet.ibm.com> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | mm: add alloc_pages_exact_nid()Andi Kleen2011-05-111-12/+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>
* | | | | | mm: use alloc_bootmem_node_nopanic() on really needed pathYinghai Lu2011-05-111-3/+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>
* | | | | | mm: check PageUnevictable in lru_deactivate_fn()Minchan Kim2011-05-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lru_deactivate_fn should not move page which in on unevictable lru into inactive list. Otherwise, we can meet BUG when we use isolate_lru_pages as __isolate_lru_page could return -EINVAL. Reported-by: Ying Han <yinghan@google.com> Tested-by: Ying Han <yinghan@google.com> Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: 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>
* | | | | | vm: fix vm_pgoff wrap in upward expansionHugh Dickins2011-05-091-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a626ca6a6564 ("vm: fix vm_pgoff wrap in stack expansion") fixed the case of an expanding mapping causing vm_pgoff wrapping when you had downward stack expansion. But there was another case where IA64 and PA-RISC expand mappings: upward expansion. This fixes that case too. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | Don't lock guardpage if the stack is growing upMikulas Patocka2011-05-091-9/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux kernel excludes guard page when performing mlock on a VMA with down-growing stack. However, some architectures have up-growing stack and locking the guard page should be excluded in this case too. This patch fixes lvm2 on PA-RISC (and possibly other architectures with up-growing stack). lvm2 calculates number of used pages when locking and when unlocking and reports an internal error if the numbers mismatch. [ Patch changed fairly extensively to also fix /proc/<pid>/maps for the grows-up case, and to move things around a bit to clean it all up and share the infrstructure with the /proc bits. Tested on ia64 that has both grow-up and grow-down segments - Linus ] Signed-off-by: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz> Tested-by: Tony Luck <tony.luck@gmail.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | VM: skip the stack guard page lookup in get_user_pages only for mlockLinus Torvalds2011-05-042-8/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The logic in __get_user_pages() used to skip the stack guard page lookup whenever the caller wasn't interested in seeing what the actual page was. But Michel Lespinasse points out that there are cases where we don't care about the physical page itself (so 'pages' may be NULL), but do want to make sure a page is mapped into the virtual address space. So using the existence of the "pages" array as an indication of whether to look up the guard page or not isn't actually so great, and we really should just use the FOLL_MLOCK bit. But because that bit was only set for the VM_LOCKED case (and not all vma's necessarily have it, even for mlock()), we couldn't do that originally. Fix that by moving the VM_LOCKED check deeper into the call-chain, which actually simplifies many things. Now mlock() gets simpler, and we can also check for FOLL_MLOCK in __get_user_pages() and the code ends up much more straightforward. Reported-and-reviewed-by: Michel Lespinasse <walken@google.com> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | slub: Fix the lockless code on 32-bit platforms with no 64-bit cmpxchgThomas Gleixner2011-05-041-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The SLUB allocator use of the cmpxchg_double logic was wrong: it actually needs the irq-safe one. That happens automatically when we use the native unlocked 'cmpxchg8b' instruction, but when compiling the kernel for older x86 CPUs that do not support that instruction, we fall back to the generic emulation code. And if you don't specify that you want the irq-safe version, the generic code ends up just open-coding the cmpxchg8b equivalent without any protection against interrupts or preemption. Which definitely doesn't work for SLUB. This was reported by Werner Landgraf <w.landgraf@ru.ru>, who saw instability with his distro-kernel that was compiled to support pretty much everything under the sun. Most big Linux distributions tend to compile for PPro and later, and would never have noticed this problem. This also fixes the prototypes for the irqsafe cmpxchg_double functions to use 'bool' like they should. [ Btw, that whole "generic code defaults to no protection" design just sounds stupid - if the code needs no protection, there is no reason to use "cmpxchg_double" to begin with. So we should probably just remove the unprotected version entirely as pointless. - Linus ] Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reported-and-tested-by: werner <w.landgraf@ru.ru> Acked-and-tested-by: Ingo Molnar <mingo@elte.hu> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1105041539050.3005@ionos Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | mm: check if PTE is already allocated during page faultMel Gorman2011-04-281-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With transparent hugepage support, handle_mm_fault() has to be careful that a normal PMD has been established before handling a PTE fault. To achieve this, it used __pte_alloc() directly instead of pte_alloc_map as pte_alloc_map is unsafe to run against a huge PMD. pte_offset_map() is called once it is known the PMD is safe. pte_alloc_map() is smart enough to check if a PTE is already present before calling __pte_alloc but this check was lost. As a consequence, PTEs may be allocated unnecessarily and the page table lock taken. Thi useless PTE does get cleaned up but it's a performance hit which is visible in page_test from aim9. This patch simply re-adds the check normally done by pte_alloc_map to check if the PTE needs to be allocated before taking the page table lock. The effect is noticable in page_test from aim9. AIM9 2.6.38-vanilla 2.6.38-checkptenone creat-clo 446.10 ( 0.00%) 424.47 (-5.10%) page_test 38.10 ( 0.00%) 42.04 ( 9.37%) brk_test 52.45 ( 0.00%) 51.57 (-1.71%) exec_test 382.00 ( 0.00%) 456.90 (16.39%) fork_test 60.11 ( 0.00%) 67.79 (11.34%) MMTests Statistics: duration Total Elapsed Time (seconds) 611.90 612.22 (While this affects 2.6.38, it is a performance rather than a functional bug and normally outside the rules -stable. While the big performance differences are to a microbench, the difference in fork and exec performance may be significant enough that -stable wants to consider the patch) Reported-by: Raz Ben Yehuda <raziebe@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | oom: use pte pages in OOM scoreKOSAKI Motohiro2011-04-281-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PTE pages eat up memory just like anything else, but we do not account for them in any way in the OOM scores. They are also _guaranteed_ to get freed up when a process is OOM killed, while RSS is not. Reported-by: Dave Hansen <dave@linux.vnet.ibm.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Oleg Nesterov <oleg@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Cc: <stable@kernel.org> [2.6.36+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | | mm: thp: fix /dev/zero MAP_PRIVATE and vm_flags cleanupsAndrea Arcangeli2011-04-281-19/+24
|/ / / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The huge_memory.c THP page fault was allowed to run if vm_ops was null (which would succeed for /dev/zero MAP_PRIVATE, as the f_op->mmap wouldn't setup a special vma->vm_ops and it would fallback to regular anonymous memory) but other THP logics weren't fully activated for vmas with vm_file not NULL (/dev/zero has a not NULL vma->vm_file). So this removes the vm_file checks so that /dev/zero also can safely use THP (the other albeit safer approach to fix this bug would have been to prevent the THP initial page fault to run if vm_file was set). After removing the vm_file checks, this also makes huge_memory.c stricter in khugepaged for the DEBUG_VM=y case. It doesn't replace the vm_file check with a is_pfn_mapping check (but it keeps checking for VM_PFNMAP under VM_BUG_ON) because for a is_cow_mapping() mapping VM_PFNMAP should only be allowed to exist before the first page fault, and in turn when vma->anon_vma is null (so preventing khugepaged registration). So I tend to think the previous comment saying if vm_file was set, VM_PFNMAP might have been set and we could still be registered in khugepaged (despite anon_vma was not NULL to be registered in khugepaged) was too paranoid. The is_linear_pfn_mapping check is also I think superfluous (as described by comment) but under DEBUG_VM it is safe to stay. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=33682 Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Caspar Zhang <bugs@casparzhang.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Rik van Riel <riel@redhat.com> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | mm/thp: use conventional format for boolean attributesBen Hutchings2011-04-141-10/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The conventional format for boolean attributes in sysfs is numeric ("0" or "1" followed by new-line). Any boolean attribute can then be read and written using a generic function. Using the strings "yes [no]", "[yes] no" (read), "yes" and "no" (write) will frustrate this. [akpm@linux-foundation.org: use kstrtoul()] [akpm@linux-foundation.org: test_bit() doesn't return 1/0, per Neil] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Johannes Weiner <jweiner@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Tested-by: David Rientjes <rientjes@google.com> Cc: NeilBrown <neilb@suse.de> Cc: <stable@kernel.org> [2.6.38.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | | oom-kill: remove boost_dying_task_prio()KOSAKI Motohiro2011-04-141-28/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an almost-revert of commit 93b43fa ("oom: give the dying task a higher priority"). That commit dramatically improved oom killer logic when a fork-bomb occurs. But I've found that it has nasty corner case. Now cpu cgroup has strange default RT runtime. It's 0! That said, if a process under cpu cgroup promote RT scheduling class, the process never run at all. If an admin inserts a !RT process into a cpu cgroup by setting rtruntime=0, usually it runs perfectly because a !RT task isn't affected by the rtruntime knob. But if it promotes an RT task via an explicit setscheduler() syscall or an OOM, the task can't run at all. In short, the oom killer doesn't work at all if admins are using cpu cgroup and don't touch the rtruntime knob. Eventually, kernel may hang up when oom kill occur. I and the original author Luis agreed to disable this logic. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Luis Claudio R. Goncalves <lclaudio@uudg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: 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>
* | | | | vmscan: all_unreclaimable() use zone->all_unreclaimable as a nameKOSAKI Motohiro2011-04-141-11/+13
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | all_unreclaimable check in direct reclaim has been introduced at 2.6.19 by following commit. 2006 Sep 25; commit 408d8544; oom: use unreclaimable info And it went through strange history. firstly, following commit broke the logic unintentionally. 2008 Apr 29; commit a41f24ea; page allocator: smarter retry of costly-order allocations Two years later, I've found obvious meaningless code fragment and restored original intention by following commit. 2010 Jun 04; commit bb21c7ce; vmscan: fix do_try_to_free_pages() return value when priority==0 But, the logic didn't works when 32bit highmem system goes hibernation and Minchan slightly changed the algorithm and fixed it . 2010 Sep 22: commit d1908362: vmscan: check all_unreclaimable in direct reclaim path But, recently, Andrey Vagin found the new corner case. Look, struct zone { .. int all_unreclaimable; .. unsigned long pages_scanned; .. } zone->all_unreclaimable and zone->pages_scanned are neigher atomic variables nor protected by lock. Therefore zones can become a state of zone->page_scanned=0 and zone->all_unreclaimable=1. In this case, current all_unreclaimable() return false even though zone->all_unreclaimabe=1. This resulted in the kernel hanging up when executing a loop of the form 1. fork 2. mmap 3. touch memory 4. read memory 5. munmmap as described in http://www.gossamer-threads.com/lists/linux/kernel/1348725#1348725 Is this ignorable minor issue? No. Unfortunately, x86 has very small dma zone and it become zone->all_unreclamble=1 easily. and if it become all_unreclaimable=1, it never restore all_unreclaimable=0. Why? if all_unreclaimable=1, vmscan only try DEF_PRIORITY reclaim and a-few-lru-pages>>DEF_PRIORITY always makes 0. that mean no page scan at all! Eventually, oom-killer never works on such systems. That said, we can't use zone->pages_scanned for this purpose. This patch restore all_unreclaimable() use zone->all_unreclaimable as old. and in addition, to add oom_killer_disabled check to avoid reintroduce the issue of commit d1908362 ("vmscan: check all_unreclaimable in direct reclaim path"). Reported-by: Andrey Vagin <avagin@openvz.org> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <npiggin@kernel.dk> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: 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>
OpenPOWER on IntegriCloud