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2010-01-21vmalloc: remove BUG_ON due to racy counting of VM_LAZY_FREEYongseok Koh1-3/+1
In free_unmap_area_noflush(), va->flags is marked as VM_LAZY_FREE first, and then vmap_lazy_nr is increased atomically. But, in __purge_vmap_area_lazy(), while traversing of vmap_are_list, nr is counted by checking VM_LAZY_FREE is set to va->flags. After counting the variable nr, kernel reads vmap_lazy_nr atomically and checks a BUG_ON condition whether nr is greater than vmap_lazy_nr to prevent vmap_lazy_nr from being negative. The problem is that, if interrupted right after marking VM_LAZY_FREE, increment of vmap_lazy_nr can be delayed. Consequently, BUG_ON condition can be met because nr is counted more than vmap_lazy_nr. It is highly probable when vmalloc/vfree are called frequently. This scenario have been verified by adding delay between marking VM_LAZY_FREE and increasing vmap_lazy_nr in free_unmap_area_noflush(). Even the vmap_lazy_nr is for checking high watermark, it never be the strict watermark. Although the BUG_ON condition is to prevent vmap_lazy_nr from being negative, vmap_lazy_nr is signed variable. So, it could go down to negative value temporarily. Consequently, removing the BUG_ON condition is proper. A possible BUG_ON message is like the below. kernel BUG at mm/vmalloc.c:517! invalid opcode: 0000 [#1] SMP EIP: 0060:[<c04824a4>] EFLAGS: 00010297 CPU: 3 EIP is at __purge_vmap_area_lazy+0x144/0x150 EAX: ee8a8818 EBX: c08e77d4 ECX: e7c7ae40 EDX: c08e77ec ESI: 000081fe EDI: e7c7ae60 EBP: e7c7ae64 ESP: e7c7ae3c DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068 Call Trace: [<c0482ad9>] free_unmap_vmap_area_noflush+0x69/0x70 [<c0482b02>] remove_vm_area+0x22/0x70 [<c0482c15>] __vunmap+0x45/0xe0 [<c04831ec>] vmalloc+0x2c/0x30 Code: 8d 59 e0 eb 04 66 90 89 cb 89 d0 e8 87 fe ff ff 8b 43 20 89 da 8d 48 e0 8d 43 20 3b 04 24 75 e7 fe 05 a8 a5 a3 c0 e9 78 ff ff ff <0f> 0b eb fe 90 8d b4 26 00 00 00 00 56 89 c6 b8 ac a5 a3 c0 31 EIP: [<c04824a4>] __purge_vmap_area_lazy+0x144/0x150 SS:ESP 0068:e7c7ae3c [ See also http://marc.info/?l=linux-kernel&m=126335856228090&w=2 ] Signed-off-by: Yongseok Koh <yongseok.koh@samsung.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-17page allocator: update NR_FREE_PAGES only when necessaryKOSAKI Motohiro1-1/+1
commit f2260e6b (page allocator: update NR_FREE_PAGES only as necessary) made one minor regression. if __rmqueue() was failed, NR_FREE_PAGES stat go wrong. this patch fixes it. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reported-by: Huang Shijie <shijie8@gmail.com> Reviewed-by: Christoph Lameter <cl@linux-foundation.org> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16nommu: fix shared mmap after truncate shrinkage problemsDavid Howells1-0/+62
Fix a problem in NOMMU mmap with ramfs whereby a shared mmap can happen over the end of a truncation. The problem is that ramfs_nommu_check_mappings() checks that the reduced file size against the VMA tree, but not the vm_region tree. The following sequence of events can cause the problem: fd = open("/tmp/x", O_RDWR|O_TRUNC|O_CREAT, 0600); ftruncate(fd, 32 * 1024); a = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); b = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); munmap(a, 32 * 1024); ftruncate(fd, 16 * 1024); c = mmap(NULL, 32 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); Mapping 'a' creates a vm_region covering 32KB of the file. Mapping 'b' sees that the vm_region from 'a' is covering the region it wants and so shares it, pinning it in memory. Mapping 'a' then goes away and the file is truncated to the end of VMA 'b'. However, the region allocated by 'a' is still in effect, and has _not_ been reduced. Mapping 'c' is then created, and because there's a vm_region covering the desired region, get_unmapped_area() is _not_ called to repeat the check, and the mapping is granted, even though the pages from the latter half of the mapping have been discarded. However: d = mmap(NULL, 16 * 1024, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0); Mapping 'd' should work, and should end up sharing the region allocated by 'a'. To deal with this, we shrink the vm_region struct during the truncation, lest do_mmap_pgoff() take it as licence to share the full region automatically without calling the get_unmapped_area() file op again. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16nommu: don't need get_unmapped_area() for NOMMUDavid Howells2-22/+1
get_unmapped_area() is unnecessary for NOMMU as no-one calls it. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16nommu: remove a superfluous check of vm_region::vm_usageDavid Howells1-4/+3
In split_vma(), there's no need to check if the VMA being split has a region that's in use by more than one VMA because: (1) The preceding test prohibits splitting of non-anonymous VMAs and regions (eg: file or chardev backed VMAs). (2) Anonymous regions can't be mapped multiple times because there's no handle by which to refer to the already existing region. (3) If a VMA has previously been split, then the region backing it has also been split into two regions, each of usage 1. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16nommu: struct vm_region's vm_usage count need not be atomicDavid Howells1-7/+7
The vm_usage count field in struct vm_region does not need to be atomic as it's only even modified whilst nommu_region_sem is write locked. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Greg Ungerer <gerg@snapgear.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16memcg: ensure list is empty at rmdirDaisuke Nishimura1-7/+4
Current mem_cgroup_force_empty() only ensures mem->res.usage == 0 on success. But this doesn't guarantee memcg's LRU is really empty, because there are some cases in which !PageCgrupUsed pages exist on memcg's LRU. For example: - Pages can be uncharged by its owner process while they are on LRU. - race between mem_cgroup_add_lru_list() and __mem_cgroup_uncharge_common(). So there can be a case in which the usage is zero but some of the LRUs are not empty. OTOH, mem_cgroup_del_lru_list(), which can be called asynchronously with rmdir, accesses the mem_cgroup, so this access can cause a problem if it races with rmdir because the mem_cgroup might have been freed by rmdir. Actually, I saw a bug which seems to be caused by this race. [1530745.949906] BUG: unable to handle kernel NULL pointer dereference at 0000000000000230 [1530745.950651] IP: [<ffffffff810fbc11>] mem_cgroup_del_lru_list+0x30/0x80 [1530745.950651] PGD 3863de067 PUD 3862c7067 PMD 0 [1530745.950651] Oops: 0002 [#1] SMP [1530745.950651] last sysfs file: /sys/devices/system/cpu/cpu7/cache/index1/shared_cpu_map [1530745.950651] CPU 3 [1530745.950651] Modules linked in: configs ipt_REJECT xt_tcpudp iptable_filter ip_tables x_tables bridge stp nfsd nfs_acl auth_rpcgss exportfs autofs4 hidp rfcomm l2cap crc16 bluetooth lockd sunrpc ib_iser rdma_cm ib_cm iw_cm ib_sa ib_mad ib_core ib_addr iscsi_tcp bnx2i cnic uio ipv6 cxgb3i cxgb3 mdio libiscsi_tcp libiscsi scsi_transport_iscsi dm_mirror dm_multipath scsi_dh video output sbs sbshc battery ac lp kvm_intel kvm sg ide_cd_mod cdrom serio_raw tpm_tis tpm tpm_bios acpi_memhotplug button parport_pc parport rtc_cmos rtc_core rtc_lib e1000 i2c_i801 i2c_core pcspkr dm_region_hash dm_log dm_mod ata_piix libata shpchp megaraid_mbox sd_mod scsi_mod megaraid_mm ext3 jbd uhci_hcd ohci_hcd ehci_hcd [last unloaded: freq_table] [1530745.950651] Pid: 19653, comm: shmem_test_02 Tainted: G M 2.6.32-mm1-00701-g2b04386 #3 Express5800/140Rd-4 [N8100-1065] [1530745.950651] RIP: 0010:[<ffffffff810fbc11>] [<ffffffff810fbc11>] mem_cgroup_del_lru_list+0x30/0x80 [1530745.950651] RSP: 0018:ffff8803863ddcb8 EFLAGS: 00010002 [1530745.950651] RAX: 00000000000001e0 RBX: ffff8803abc02238 RCX: 00000000000001e0 [1530745.950651] RDX: 0000000000000000 RSI: ffff88038611a000 RDI: ffff8803abc02238 [1530745.950651] RBP: ffff8803863ddcc8 R08: 0000000000000002 R09: ffff8803a04c8643 [1530745.950651] R10: 0000000000000000 R11: ffffffff810c7333 R12: 0000000000000000 [1530745.950651] R13: ffff880000017f00 R14: 0000000000000092 R15: ffff8800179d0310 [1530745.950651] FS: 0000000000000000(0000) GS:ffff880017800000(0000) knlGS:0000000000000000 [1530745.950651] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [1530745.950651] CR2: 0000000000000230 CR3: 0000000379d87000 CR4: 00000000000006e0 [1530745.950651] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1530745.950651] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [1530745.950651] Process shmem_test_02 (pid: 19653, threadinfo ffff8803863dc000, task ffff88038612a8a0) [1530745.950651] Stack: [1530745.950651] ffffea00040c2fe8 0000000000000000 ffff8803863ddd98 ffffffff810c739a [1530745.950651] <0> 00000000863ddd18 000000000000000c 0000000000000000 0000000000000000 [1530745.950651] <0> 0000000000000002 0000000000000000 ffff8803863ddd68 0000000000000046 [1530745.950651] Call Trace: [1530745.950651] [<ffffffff810c739a>] release_pages+0x142/0x1e7 [1530745.950651] [<ffffffff810c778f>] ? pagevec_move_tail+0x6e/0x112 [1530745.950651] [<ffffffff810c781e>] pagevec_move_tail+0xfd/0x112 [1530745.950651] [<ffffffff810c78a9>] lru_add_drain+0x76/0x94 [1530745.950651] [<ffffffff810dba0c>] exit_mmap+0x6e/0x145 [1530745.950651] [<ffffffff8103f52d>] mmput+0x5e/0xcf [1530745.950651] [<ffffffff81043ea8>] exit_mm+0x11c/0x129 [1530745.950651] [<ffffffff8108fb29>] ? audit_free+0x196/0x1c9 [1530745.950651] [<ffffffff81045353>] do_exit+0x1f5/0x6b7 [1530745.950651] [<ffffffff8106133f>] ? up_read+0x2b/0x2f [1530745.950651] [<ffffffff8137d187>] ? lockdep_sys_exit_thunk+0x35/0x67 [1530745.950651] [<ffffffff81045898>] do_group_exit+0x83/0xb0 [1530745.950651] [<ffffffff810458dc>] sys_exit_group+0x17/0x1b [1530745.950651] [<ffffffff81002c1b>] system_call_fastpath+0x16/0x1b [1530745.950651] Code: 54 53 0f 1f 44 00 00 83 3d cc 29 7c 00 00 41 89 f4 75 63 eb 4e 48 83 7b 08 00 75 04 0f 0b eb fe 48 89 df e8 18 f3 ff ff 44 89 e2 <48> ff 4c d0 50 48 8b 05 2b 2d 7c 00 48 39 43 08 74 39 48 8b 4b [1530745.950651] RIP [<ffffffff810fbc11>] mem_cgroup_del_lru_list+0x30/0x80 [1530745.950651] RSP <ffff8803863ddcb8> [1530745.950651] CR2: 0000000000000230 [1530745.950651] ---[ end trace c3419c1bb8acc34f ]--- [1530745.950651] Fixing recursive fault but reboot is needed! The problem here is pages on LRU may contain pointer to stale memcg. To make res->usage to be 0, all pages on memcg must be uncharged or moved to another(parent) memcg. Moved page_cgroup have already removed from original LRU, but uncharged page_cgroup contains pointer to memcg withou PCG_USED bit. (This asynchronous LRU work is for improving performance.) If PCG_USED bit is not set, page_cgroup will never be added to memcg's LRU. So, about pages not on LRU, they never access stale pointer. Then, what we have to take care of is page_cgroup _on_ LRU list. This patch fixes this problem by making mem_cgroup_force_empty() visit all LRUs before exiting its loop and guarantee there are no pages on its LRU. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16vmscan: kswapd: don't retry balance_pgdat() if all zones are unreclaimableKOSAKI Motohiro1-0/+3
Commit f50de2d3 (vmscan: have kswapd sleep for a short interval and double check it should be asleep) can cause kswapd to enter an infinite loop if running on a single-CPU system. If all zones are unreclaimble, sleeping_prematurely return 1 and kswapd will call balance_pgdat() again. but it's totally meaningless, balance_pgdat() doesn't anything against unreclaimable zone! Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Reported-by: Will Newton <will.newton@gmail.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Tested-by: Will Newton <will.newton@gmail.com> Reviewed-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-16mm/page_alloc: fix the range check for backward mergingKazuhisa Ichikawa1-1/+1
The current check for 'backward merging' within add_active_range() does not seem correct. start_pfn must be compared against early_node_map[i].start_pfn (and NOT against .end_pfn) to find out whether the new region is backward-mergeable with the existing range. Signed-off-by: Kazuhisa Ichikawa <ki@epsilou.com> Acked-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-14vfs: Fix vmtruncate() regressionOGAWA Hirofumi1-16/+14
If __block_prepare_write() was failed in block_write_begin(), the allocated blocks can be outside of ->i_size. But new truncate_pagecache() in vmtuncate() does nothing if new < old. It means the above usage is not working anymore. So, this patch fixes it by removing "new < old" check. It would need more cleanup/change. But, now -rc and truncate working is in progress, so, this tried to fix it minimum change. Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11mm: hugetlb: fix clear_huge_page()Andrea Arcangeli1-1/+1
sz is in bytes, MAX_ORDER_NR_PAGES is in pages. Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: David Gibson <dwg@au1.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: David Rientjes <rientjes@google.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-11percpu: avoid calling __pcpu_ptr_to_addr(NULL)Andrew Morton1-1/+3
__pcpu_ptr_to_addr() can be overridden by the architecture and might not behave well if passed a NULL pointer. So avoid calling it until we have verified that its arg is not NULL. Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-07maccess,probe_kernel: Allow arch specific override probe_kernel_(read|write)Jason Wessel1-2/+9
Some archs such as blackfin, would like to have an arch specific probe_kernel_read() and probe_kernel_write() implementation which can fall back to the generic implementation if no special operations are needed. CC: Thomas Gleixner <tglx@linutronix.de> CC: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org>
2010-01-07NOMMU: Use copy_*_user_page() in access_process_vm()Jie Zhang1-2/+4
The MMU code uses the copy_*_user_page() variants in access_process_vm() rather than copy_*_user() as the former includes an icache flush. This is important when doing things like setting software breakpoints with gdb. So switch the NOMMU code over to do the same. This patch makes the reasonable assumption that copy_from_user_page() won't fail - which is probably fine, as we've checked the VMA from which we're copying is usable, and the copy is not allowed to cross VMAs. The one case where it might go wrong is if the VMA is a device rather than RAM, and that device returns an error which - in which case rubbish will be returned rather than EIO. Signed-off-by: Jie Zhang <jie.zhang@analog.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: David McCullough <david_mccullough@mcafee.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-01-07NOMMU: Avoiding duplicate icache flushes of shared mapsMike Frysinger1-3/+8
When working with FDPIC, there are many shared mappings of read-only code regions between applications (the C library, applet packages like busybox, etc.), but the current do_mmap_pgoff() function will issue an icache flush whenever a VMA is added to an MM instead of only doing it when the map is initially created. The flush can instead be done when a region is first mmapped PROT_EXEC. Note that we may not rely on the first mapping of a region being executable - it's possible for it to be PROT_READ only, so we have to remember whether we've flushed the region or not, and then flush the entire region when a bit of it is made executable. However, this also affects the brk area. That will no longer be executable. We can mprotect() it to PROT_EXEC on MPU-mode kernels, but for NOMMU mode kernels, when it increases the brk allocation, making sys_brk() flush the extra from the icache should suffice. The brk area probably isn't used by NOMMU programs since the brk area can only use up the leavings from the stack allocation, where the stack allocation is larger than requested. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-31Merge branch 'slab/urgent' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: SLAB: Fix lockdep annotation breakage
2009-12-30mm: move sys_mmap_pgoff from util.cHugh Dickins3-44/+65
Move sys_mmap_pgoff() from mm/util.c to mm/mmap.c and mm/nommu.c, where we'd expect to find such code: especially now that it contains the MAP_HUGETLB handling. Revert mm/util.c to how it was in 2.6.32. This patch just ignores MAP_HUGETLB in the nommu case, as in 2.6.32, whereas 2.6.33-rc2 reported -ENOSYS. Perhaps validate_mmap_request() should reject it with -EINVAL? Add that later if necessary. Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-28SLAB: Fix lockdep annotation breakagePekka Enberg1-2/+2
Commit ce79ddc8e2376a9a93c7d42daf89bfcbb9187e62 ("SLAB: Fix lockdep annotations for CPU hotplug") broke init_node_lock_keys() off-slab logic which causes lockdep false positives. Fix that up by reverting the logic back to original while keeping CPU hotplug fixes intact. Reported-and-tested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-and-tested-by: Andi Kleen <andi@firstfloor.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2009-12-25Merge branch 'sysctl' of ↵Linus Torvalds1-4/+7
git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc-2.6 * 'sysctl' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-misc-2.6: SYSCTL: Add a mutex to the page_alloc zone order sysctl SYSCTL: Print binary sysctl warnings (nearly) only once
2009-12-25Merge branch 'hwpoison' of ↵Linus Torvalds2-1/+10
git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: HWPOISON: Add PROC_FS dependency to hwpoison injector v2
2009-12-23SYSCTL: Add a mutex to the page_alloc zone order sysctlAndi Kleen1-4/+7
The zone list code clearly cannot tolerate concurrent writers (I couldn't find any locks for that), so simply add a global mutex. No need for RCU in this case. Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-23Merge branch 'merge' of ↵Linus Torvalds1-7/+50
git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc * 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (36 commits) powerpc/gc/wii: Remove get_irq_desc() powerpc/gc/wii: hlwd-pic: convert irq_desc.lock to raw_spinlock powerpc/gamecube/wii: Fix off-by-one error in ugecon/usbgecko_udbg powerpc/mpic: Fix problem that affinity is not updated powerpc/mm: Fix stupid bug in subpge protection handling powerpc/iseries: use DECLARE_COMPLETION_ONSTACK for non-constant completion powerpc: Fix MSI support on U4 bridge PCIe slot powerpc: Handle VSX alignment faults correctly in little-endian mode powerpc/mm: Fix typo of cpumask_clear_cpu() powerpc/mm: Fix hash_utils_64.c compile errors with DEBUG enabled. powerpc: Convert BUG() to use unreachable() powerpc/pseries: Make declarations of cpu_hotplug_driver_lock() ANSI compatible. powerpc/pseries: Don't panic when H_PROD fails during cpu-online. powerpc/mm: Fix a WARN_ON() with CONFIG_DEBUG_PAGEALLOC and CONFIG_DEBUG_VM powerpc/defconfigs: Set HZ=100 on pseries and ppc64 defconfigs powerpc/defconfigs: Disable token ring in powerpc defconfigs powerpc/defconfigs: Reduce 64bit vmlinux by making acenic and cramfs modules powerpc/pseries: Select XICS and PCI_MSI PSERIES powerpc/85xx: Wrong variable returned on error powerpc/iseries: Convert to proc_fops ...
2009-12-21HWPOISON: Add PROC_FS dependency to hwpoison injector v2Andi Kleen2-1/+10
The injector filter requires stable_page_flags() which is supplied by procfs. So make it dependent on that. Also add ifdefs around the filter code in memory-failure.c so that when the filter is disabled due to missing dependencies the whole code still builds. Reported-by: Ingo Molnar Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-12-19Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86, irq: Allow 0xff for /proc/irq/[n]/smp_affinity on an 8-cpu system Makefile: Unexport LC_ALL instead of clearing it x86: Fix objdump version check in arch/x86/tools/chkobjdump.awk x86: Reenable TSC sync check at boot, even with NONSTOP_TSC x86: Don't use POSIX character classes in gen-insn-attr-x86.awk Makefile: set LC_CTYPE, LC_COLLATE, LC_NUMERIC to C x86: Increase MAX_EARLY_RES; insufficient on 32-bit NUMA x86: Fix checking of SRAT when node 0 ram is not from 0 x86, cpuid: Add "volatile" to asm in native_cpuid() x86, msr: msrs_alloc/free for CONFIG_SMP=n x86, amd: Get multi-node CPU info from NodeId MSR instead of PCI config space x86: Add IA32_TSC_AUX MSR and use it x86, msr/cpuid: Register enough minors for the MSR and CPUID drivers initramfs: add missing decompressor error check bzip2: Add missing checks for malloc returning NULL bzip2/lzma/gzip: pre-boot malloc doesn't return NULL on failure
2009-12-18mm: Add notifier in pageblock isolation for balloon driversRobert Jennings1-7/+50
Memory balloon drivers can allocate a large amount of memory which is not movable but could be freed to accomodate memory hotplug remove. Prior to calling the memory hotplug notifier chain the memory in the pageblock is isolated. Currently, if the migrate type is not MIGRATE_MOVABLE the isolation will not proceed, causing the memory removal for that page range to fail. Rather than failing pageblock isolation if the migrateteype is not MIGRATE_MOVABLE, this patch checks if all of the pages in the pageblock, and not on the LRU, are owned by a registered balloon driver (or other entity) using a notifier chain. If all of the non-movable pages are owned by a balloon, they can be freed later through the memory notifier chain and the range can still be isolated in set_migratetype_isolate(). Signed-off-by: Robert Jennings <rcj@linux.vnet.ibm.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Ingo Molnar <mingo@elte.hu> Cc: Brian King <brking@linux.vnet.ibm.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Gerald Schaefer <geralds@linux.vnet.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-18Merge branch 'cpumask-cleanups' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus * 'cpumask-cleanups' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: cpumask: rename tsk_cpumask to tsk_cpus_allowed cpumask: don't recommend set_cpus_allowed hack in Documentation/cpu-hotplug.txt cpumask: avoid dereferencing struct cpumask cpumask: convert drivers/idle/i7300_idle.c to cpumask_var_t cpumask: use modern cpumask style in drivers/scsi/fcoe/fcoe.c cpumask: avoid deprecated function in mm/slab.c cpumask: use cpu_online in kernel/perf_event.c
2009-12-18Merge branch 'for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: Keys: KEYCTL_SESSION_TO_PARENT needs TIF_NOTIFY_RESUME architecture support NOMMU: Optimise away the {dac_,}mmap_min_addr tests security/min_addr.c: make init_mmap_min_addr() static keys: PTR_ERR return of wrong pointer in keyctl_get_security()
2009-12-18Merge branch 'kmemleak' of git://linux-arm.org/linux-2.6Linus Torvalds2-91/+107
* 'kmemleak' of git://linux-arm.org/linux-2.6: kmemleak: fix kconfig for crc32 build error kmemleak: Reduce the false positives by checking for modified objects kmemleak: Show the age of an unreferenced object kmemleak: Release the object lock before calling put_object() kmemleak: Scan the _ftrace_events section in modules kmemleak: Simplify the kmemleak_scan_area() function prototype kmemleak: Do not use off-slab management with SLAB_NOLEAKTRACE
2009-12-18readahead: add blk_run_backing_devHisashi Hifumi1-0/+12
I added blk_run_backing_dev on page_cache_async_readahead so readahead I/O is unpluged to improve throughput on especially RAID environment. The normal case is, if page N become uptodate at time T(N), then T(N) <= T(N+1) holds. With RAID (and NFS to some degree), there is no strict ordering, the data arrival time depends on runtime status of individual disks, which breaks that formula. So in do_generic_file_read(), just after submitting the async readahead IO request, the current page may well be uptodate, so the page won't be locked, and the block device won't be implicitly unplugged: if (PageReadahead(page)) page_cache_async_readahead() if (!PageUptodate(page)) goto page_not_up_to_date; //... page_not_up_to_date: lock_page_killable(page); Therefore explicit unplugging can help. Following is the test result with dd. #dd if=testdir/testfile of=/dev/null bs=16384 -2.6.30-rc6 1048576+0 records in 1048576+0 records out 17179869184 bytes (17 GB) copied, 224.182 seconds, 76.6 MB/s -2.6.30-rc6-patched 1048576+0 records in 1048576+0 records out 17179869184 bytes (17 GB) copied, 206.465 seconds, 83.2 MB/s (7Disks RAID-0 Array) -2.6.30-rc6 1054976+0 records in 1054976+0 records out 17284726784 bytes (17 GB) copied, 212.233 seconds, 81.4 MB/s -2.6.30-rc6-patched 1054976+0 records out 17284726784 bytes (17 GB) copied, 198.878 seconds, 86.9 MB/s (7Disks RAID-5 Array) The patch was found to improve performance with the SCST scsi target driver. See http://sourceforge.net/mailarchive/forum.php?thread_name=a0272b440906030714g67eabc5k8f847fb1e538cc62%40mail.gmail.com&forum_name=scst-devel [akpm@linux-foundation.org: unbust comment layout] [akpm@linux-foundation.org: "fix" CONFIG_BLOCK=n] Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Acked-by: Wu Fengguang <fengguang.wu@intel.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Tested-by: Ronald <intercommit@gmail.com> Cc: Bart Van Assche <bart.vanassche@gmail.com> Cc: Vladislav Bolkhovitin <vst@vlnb.net> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17cpumask: avoid deprecated function in mm/slab.cRusty Russell1-1/+1
These days we use cpumask_empty() which takes a pointer. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christoph Lameter <cl@linux-foundation.org>
2009-12-17Fix breakage in shmem.cAl Viro1-0/+2
Replacing error = 0; if (error) op with nothing is not quite an equivalent transformation ;-) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-17x86: Fix checking of SRAT when node 0 ram is not from 0Yinghai Lu1-2/+2
Found one system that boot from socket1 instead of socket0, SRAT get rejected... [ 0.000000] SRAT: Node 1 PXM 0 0-a0000 [ 0.000000] SRAT: Node 1 PXM 0 100000-80000000 [ 0.000000] SRAT: Node 1 PXM 0 100000000-2080000000 [ 0.000000] SRAT: Node 0 PXM 1 2080000000-4080000000 [ 0.000000] SRAT: Node 2 PXM 2 4080000000-6080000000 [ 0.000000] SRAT: Node 3 PXM 3 6080000000-8080000000 [ 0.000000] SRAT: Node 4 PXM 4 8080000000-a080000000 [ 0.000000] SRAT: Node 5 PXM 5 a080000000-c080000000 [ 0.000000] SRAT: Node 6 PXM 6 c080000000-e080000000 [ 0.000000] SRAT: Node 7 PXM 7 e080000000-10080000000 ... [ 0.000000] NUMA: Allocated memnodemap from 500000 - 701040 [ 0.000000] NUMA: Using 20 for the hash shift. [ 0.000000] Adding active range (0, 0x2080000, 0x4080000) 0 entries of 3200 used [ 0.000000] Adding active range (1, 0x0, 0x96) 1 entries of 3200 used [ 0.000000] Adding active range (1, 0x100, 0x7f750) 2 entries of 3200 used [ 0.000000] Adding active range (1, 0x100000, 0x2080000) 3 entries of 3200 used [ 0.000000] Adding active range (2, 0x4080000, 0x6080000) 4 entries of 3200 used [ 0.000000] Adding active range (3, 0x6080000, 0x8080000) 5 entries of 3200 used [ 0.000000] Adding active range (4, 0x8080000, 0xa080000) 6 entries of 3200 used [ 0.000000] Adding active range (5, 0xa080000, 0xc080000) 7 entries of 3200 used [ 0.000000] Adding active range (6, 0xc080000, 0xe080000) 8 entries of 3200 used [ 0.000000] Adding active range (7, 0xe080000, 0x10080000) 9 entries of 3200 used [ 0.000000] SRAT: PXMs only cover 917504MB of your 1048566MB e820 RAM. Not used. [ 0.000000] SRAT: SRAT not used. the early_node_map is not sorted because node0 with non zero start come first. so try to sort it right away after all regions are registered. also fixs refression by 8716273c (x86: Export srat physical topology) -v2: make it more solid to handle cross node case like node0 [0,4g), [8,12g) and node1 [4g, 8g), [12g, 16g) -v3: update comments. Reported-and-tested-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> LKML-Reference: <4B2579D2.3010201@kernel.org> Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2009-12-17NOMMU: Optimise away the {dac_,}mmap_min_addr testsDavid Howells1-0/+1
In NOMMU mode clamp dac_mmap_min_addr to zero to cause the tests on it to be skipped by the compiler. We do this as the minimum mmap address doesn't make any sense in NOMMU mode. mmap_min_addr and round_hint_to_min() can be discarded entirely in NOMMU mode. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-12-16Merge branch 'hwpoison' of ↵Linus Torvalds8-77/+673
git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (34 commits) HWPOISON: Remove stray phrase in a comment HWPOISON: Try to allocate migration page on the same node HWPOISON: Don't do early filtering if filter is disabled HWPOISON: Add a madvise() injector for soft page offlining HWPOISON: Add soft page offline support HWPOISON: Undefine short-hand macros after use to avoid namespace conflict HWPOISON: Use new shake_page in memory_failure HWPOISON: Use correct name for MADV_HWPOISON in documentation HWPOISON: mention HWPoison in Kconfig entry HWPOISON: Use get_user_page_fast in hwpoison madvise HWPOISON: add an interface to switch off/on all the page filters HWPOISON: add memory cgroup filter memcg: add accessor to mem_cgroup.css memcg: rename and export try_get_mem_cgroup_from_page() HWPOISON: add page flags filter mm: export stable page flags HWPOISON: limit hwpoison injector to known page types HWPOISON: add fs/device filters HWPOISON: return 0 to indicate success reliably HWPOISON: make semantics of IGNORED/DELAYED clear ...
2009-12-16Merge branch 'master' of ↵Linus Torvalds4-221/+37
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (38 commits) direct I/O fallback sync simplification ocfs: stop using do_sync_mapping_range cleanup blockdev_direct_IO locking make generic_acl slightly more generic sanitize xattr handler prototypes libfs: move EXPORT_SYMBOL for d_alloc_name vfs: force reval of target when following LAST_BIND symlinks (try #7) ima: limit imbalance msg Untangling ima mess, part 3: kill dead code in ima Untangling ima mess, part 2: deal with counters Untangling ima mess, part 1: alloc_file() O_TRUNC open shouldn't fail after file truncation ima: call ima_inode_free ima_inode_free IMA: clean up the IMA counts updating code ima: only insert at inode creation time ima: valid return code from ima_inode_alloc fs: move get_empty_filp() deffinition to internal.h Sanitize exec_permission_lite() Kill cached_lookup() and real_lookup() Kill path_lookup_open() ... Trivial conflicts in fs/direct-io.c
2009-12-16direct I/O fallback sync simplificationChristoph Hellwig1-14/+1
In the case of direct I/O falling back to buffered I/O we sync data twice currently: once at the end of generic_file_buffered_write using filemap_write_and_wait_range and once a little later in __generic_file_aio_write using do_sync_mapping_range with all flags set. The wait before write of the do_sync_mapping_range call does not make any sense, so just keep the filemap_write_and_wait_range call and move it to the right spot. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16make generic_acl slightly more genericChristoph Hellwig3-141/+10
Now that we cache the ACL pointers in the generic inode all the generic_acl cruft can go away and generic_acl.c can directly implement xattr handlers dealing with the full Posix ACL semantics for in-memory filesystems. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16sanitize xattr handler prototypesChristoph Hellwig2-67/+30
Add a flags argument to struct xattr_handler and pass it to all xattr handler methods. This allows using the same methods for multiple handlers, e.g. for the ACL methods which perform exactly the same action for the access and default ACLs, just using a different underlying attribute. With a little more groundwork it'll also allow sharing the methods for the regular user/trusted/secure handlers in extN, ocfs2 and jffs2 like it's already done for xfs in this patch. Also change the inode argument to the handlers to a dentry to allow using the handlers mechnism for filesystems that require it later, e.g. cifs. [with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16Untangling ima mess, part 1: alloc_file()Al Viro1-2/+0
There are 2 groups of alloc_file() callers: * ones that are followed by ima_counts_get * ones giving non-regular files So let's pull that ima_counts_get() into alloc_file(); it's a no-op in case of non-regular files. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switch alloc_file() to passing struct pathAl Viro1-6/+8
... and have the caller grab both mnt and dentry; kill leak in infiniband, while we are at it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16switch shmem_file_setup() to alloc_file()Al Viro1-12/+9
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16memcg: code clean, remove unused variable in mem_cgroup_resize_limit()Bob Liu1-3/+1
Variable `progress' isn't used in mem_cgroup_resize_limit() any more. Remove it. [akpm@linux-foundation.org: cleanup] Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: remove memcg_tasklistDaisuke Nishimura1-5/+0
memcg_tasklist was introduced at commit 7f4d454d(memcg: avoid deadlock caused by race between oom and cpuset_attach) instead of cgroup_mutex to fix a deadlock problem. The cgroup_mutex, which was removed by the commit, in mem_cgroup_out_of_memory() was originally introduced at commit c7ba5c9e (Memory controller: OOM handling). IIUC, the intention of this cgroup_mutex was to prevent task move during select_bad_process() so that situations like below can be avoided. Assume cgroup "foo" has exceeded its limit and is about to trigger oom. 1. Process A, which has been in cgroup "baa" and uses large memory, is just moved to cgroup "foo". Process A can be the candidates for being killed. 2. Process B, which has been in cgroup "foo" and uses large memory, is just moved from cgroup "foo". Process B can be excluded from the candidates for being killed. But these race window exists anyway even if we hold a lock, because __mem_cgroup_try_charge() decides wether it should trigger oom or not outside of the lock. So the original cgroup_mutex in mem_cgroup_out_of_memory and thus current memcg_tasklist has no use. And IMHO, those races are not so critical for users. This patch removes it and make codes simpler. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: Balbir Singh <balbir@linux.vnet.ibm.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>
2009-12-16memcg: avoid oom-killing innocent task in case of use_hierarchyDaisuke Nishimura2-8/+15
task_in_mem_cgroup(), which is called by select_bad_process() to check whether a task can be a candidate for being oom-killed from memcg's limit, checks "curr->use_hierarchy"("curr" is the mem_cgroup the task belongs to). But this check return true(it's false positive) when: <some path>/aa use_hierarchy == 0 <- hitting limit <some path>/aa/00 use_hierarchy == 1 <- the task belongs to This leads to killing an innocent task in aa/00. This patch is a fix for this bug. And this patch also fixes the arg for mem_cgroup_print_oom_info(). We should print information of mem_cgroup which the task being killed, not current, belongs to. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: cleanup mem_cgroup_move_parent()Daisuke Nishimura1-49/+35
mem_cgroup_move_parent() calls try_charge first and cancel_charge on failure. IMHO, charge/uncharge(especially charge) is high cost operation, so we should avoid it as far as possible. This patch tries to delay try_charge in mem_cgroup_move_parent() by re-ordering checks it does. And this patch renames mem_cgroup_move_account() to __mem_cgroup_move_account(), changes the return value of __mem_cgroup_move_account() from int to void, and adds a new wrapper(mem_cgroup_move_account()), which checks whether a @pc is valid for moving account and calls __mem_cgroup_move_account(). This patch removes the last caller of trylock_page_cgroup(), so removes its definition too. Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: add mem_cgroup_cancel_charge()Daisuke Nishimura1-20/+18
There are some places calling both res_counter_uncharge() and css_put() to cancel the charge and the refcnt we have got by mem_cgroup_tyr_charge(). This patch introduces mem_cgroup_cancel_charge() and call it in those places. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Reviewed-by: Balbir Singh <balbir@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: make memcg's file mapped consistent with global VMKAMEZAWA Hiroyuki2-14/+11
In global VM, FILE_MAPPED is used but memcg uses MAPPED_FILE. This makes grep difficult. Replace memcg's MAPPED_FILE with FILE_MAPPED And in global VM, mapped shared memory is accounted into FILE_MAPPED. But memcg doesn't. fix it. Note: page_is_file_cache() just checks SwapBacked or not. So, we need to check PageAnon. Cc: Balbir Singh <balbir@in.ibm.com> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-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>
2009-12-16memcg: coalesce charging via percpu storageKAMEZAWA Hiroyuki1-6/+156
This is a patch for coalescing access to res_counter at charging by percpu caching. At charge, memcg charges 64pages and remember it in percpu cache. Because it's cache, drain/flush if necessary. This version uses public percpu area. 2 benefits for using public percpu area. 1. Sum of stocked charge in the system is limited to # of cpus not to the number of memcg. This shows better synchonization. 2. drain code for flush/cpuhotplug is very easy (and quick) The most important point of this patch is that we never touch res_counter in fast path. The res_counter is system-wide shared counter which is modified very frequently. We shouldn't touch it as far as we can for avoiding false sharing. On x86-64 8cpu server, I tested overheads of memcg at page fault by running a program which does map/fault/unmap in a loop. Running a task per a cpu by taskset and see sum of the number of page faults in 60secs. [without memcg config] 40156968 page-faults # 0.085 M/sec ( +- 0.046% ) 27.67 cache-miss/faults [root cgroup] 36659599 page-faults # 0.077 M/sec ( +- 0.247% ) 31.58 cache miss/faults [in a child cgroup] 18444157 page-faults # 0.039 M/sec ( +- 0.133% ) 69.96 cache miss/faults [ + coalescing uncharge patch] 27133719 page-faults # 0.057 M/sec ( +- 0.155% ) 47.16 cache miss/faults [ + coalescing uncharge patch + this patch ] 34224709 page-faults # 0.072 M/sec ( +- 0.173% ) 34.69 cache miss/faults Changelog (since Oct/2): - updated comments - replaced get_cpu_var() with __get_cpu_var() if possible. - removed mutex for system-wide drain. adds a counter instead of it. - removed CONFIG_HOTPLUG_CPU Changelog (old): - rebased onto the latest mmotm - moved charge size check before __GFP_WAIT check for avoiding unnecesary - added asynchronous flush routine. - fixed bugs pointed out by Nishimura-san. [akpm@linux-foundation.org: tweak comments] [nishimura@mxp.nes.nec.co.jp: don't do INIT_WORK() repeatedly against the same work_struct] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: coalesce uncharge during unmap/truncateKAMEZAWA Hiroyuki3-6/+98
In massive parallel enviroment, res_counter can be a performance bottleneck. One strong techinque to reduce lock contention is reducing calls by coalescing some amount of calls into one. Considering charge/uncharge chatacteristic, - charge is done one by one via demand-paging. - uncharge is done by - in chunk at munmap, truncate, exit, execve... - one by one via vmscan/paging. It seems we have a chance to coalesce uncharges for improving scalability at unmap/truncation. This patch is a for coalescing uncharge. For avoiding scattering memcg's structure to functions under /mm, this patch adds memcg batch uncharge information to the task. A reason for per-task batching is for making use of caller's context information. We do batched uncharge (deleyed uncharge) when truncation/unmap occurs but do direct uncharge when uncharge is called by memory reclaim (vmscan.c). The degree of coalescing depends on callers - at invalidate/trucate... pagevec size - at unmap ....ZAP_BLOCK_SIZE (memory itself will be freed in this degree.) Then, we'll not coalescing too much. On x86-64 8cpu server, I tested overheads of memcg at page fault by running a program which does map/fault/unmap in a loop. Running a task per a cpu by taskset and see sum of the number of page faults in 60secs. [without memcg config] 40156968 page-faults # 0.085 M/sec ( +- 0.046% ) 27.67 cache-miss/faults [root cgroup] 36659599 page-faults # 0.077 M/sec ( +- 0.247% ) 31.58 miss/faults [in a child cgroup] 18444157 page-faults # 0.039 M/sec ( +- 0.133% ) 69.96 miss/faults [child with this patch] 27133719 page-faults # 0.057 M/sec ( +- 0.155% ) 47.16 miss/faults We can see some amounts of improvement. (root cgroup doesn't affected by this patch) Another patch for "charge" will follow this and above will be improved more. Changelog(since 2009/10/02): - renamed filed of memcg_batch (as pages to bytes, memsw to memsw_bytes) - some clean up and commentary/description updates. - added initialize code to copy_process(). (possible bug fix) Changelog(old): - fixed !CONFIG_MEM_CGROUP case. - rebased onto the latest mmotm + softlimit fix patches. - unified patch for callers - added commetns. - make ->do_batch as bool. - removed css_get() at el. We don't need it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16memcg: fix memory.memsw.usage_in_bytes for root cgroupKirill A. Shutemov1-0/+1
A memory cgroup has a memory.memsw.usage_in_bytes file. It shows the sum of the usage of pages and swapents in the cgroup. Presently the root cgroup's memsw.usage_in_bytes shows the wrong value - the number of swapents are not added. So take MEM_CGROUP_STAT_SWAPOUT into account. Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name> Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>