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2012-09-05mm/sl[aou]b: Move kmem_cache allocations into common codeChristoph Lameter5-70/+52
Shift the allocations to common code. That way the allocation and freeing of the kmem_cache structures is handled by common code. Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Move sysfs_slab_add to commonChristoph Lameter3-13/+13
Simplify locking by moving the slab_add_sysfs after all locks have been dropped. Eases the upcoming move to provide sysfs support for all allocators. Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Do slab aliasing call from common codeChristoph Lameter3-4/+25
The slab aliasing logic causes some strange contortions in slub. So add a call to deal with aliases to slab_common.c but disable it for other slab allocators by providng stubs that fail to create aliases. Full general support for aliases will require additional cleanup passes and more standardization of fields in kmem_cache. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Move duping of slab name to slab_common.cChristoph Lameter2-28/+23
Duping of the slabname has to be done by each slab. Moving this code to slab_common avoids duplicate implementations. With this patch we have common string handling for all slab allocators. Strings passed to kmem_cache_create() are copied internally. Subsystems can create temporary strings to create slab caches. Slabs allocated in early states of bootstrap will never be freed (and those can never be freed since they are essential to slab allocator operations). During bootstrap we therefore do not have to worry about duping names. Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Get rid of __kmem_cache_destroyChristoph Lameter5-36/+26
What is done there can be done in __kmem_cache_shutdown. This affects RCU handling somewhat. On rcu free all slab allocators do not refer to other management structures than the kmem_cache structure. Therefore these other structures can be freed before the rcu deferred free to the page allocator occurs. Reviewed-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Move freeing of kmem_cache structure to common codeChristoph Lameter4-5/+1
The freeing action is basically the same in all slab allocators. Move to the common kmem_cache_destroy() function. Reviewed-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Use "kmem_cache" name for slab cache with kmem_cache structChristoph Lameter5-37/+52
Make all allocators use the "kmem_cache" slabname for the "kmem_cache" structure. Reviewed-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Extract a common function for kmem_cache_destroyChristoph Lameter5-75/+49
kmem_cache_destroy does basically the same in all allocators. Extract common code which is easy since we already have common mutex handling. Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/sl[aou]b: Move list_add() to slab_common.cChristoph Lameter4-4/+16
Move the code to append the new kmem_cache to the list of slab caches to the kmem_cache_create code in the shared code. This is possible now since the acquisition of the mutex was moved into kmem_cache_create(). Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: Glauber Costa <glommer@parallels.com> Reviewed-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/slab_common: Improve error handling in kmem_cache_createChristoph Lameter1-4/+24
Instead of using s == NULL use an errorcode. This allows much more detailed diagnostics as to what went wrong. As we add more functionality from the slab allocators to the common kmem_cache_create() function we will also add more error conditions. Print the error code during the panic as well as in a warning if the module can handle failure. The API for kmem_cache_create() currently does not allow the returning of an error code. Return NULL but log the cause of the problem in the syslog. Reviewed-by: Glauber Costa <glommer@parallels.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/slub: Use kmem_cache for the kmem_cache structureChristoph Lameter1-4/+4
Do not use kmalloc() but kmem_cache_alloc() for the allocation of the kmem_cache structures in slub. Reviewed-by: Glauber Costa <glommer@parallels.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-05mm/slub: Add debugging to verify correct cache use on kmem_cache_free()Christoph Lameter1-0/+7
Add additional debugging to check that the objects is actually from the cache the caller claims. Doing so currently trips up some other debugging code. It takes a lot to infer from that what was happening. Reviewed-by: Glauber Costa <glommer@parallels.com> Signed-off-by: Christoph Lameter <cl@linux.com> [ penberg@kernel.org: Use pr_err() ] Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-09-04mm: Use __do_krealloc to do the krealloc jobEzequiel Garcia1-14/+21
Without this patch we can get (many) kmem trace events with call site at krealloc(). This happens because krealloc is calling __krealloc, which performs the allocation through kmalloc_track_caller. Since neither krealloc nor __krealloc are marked inline explicitly, the caller can be traced as being krealloc, which clearly is not the intended behavior. This patch allows to get the real caller of krealloc, by creating an always inlined function __do_krealloc, thus tracing the call site accurately. Acked-by: Christoph Lameter <cl@linux.com> Cc: Glauber Costa <glommer@parallels.com> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-17mm, slab: remove page_get_cacheDavid Rientjes1-6/+0
page_get_cache() isn't called from anything, so remove it. Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16mm/slab: restructure kmem_cache_create() debug checksShuah Khan1-49/+48
kmem_cache_create() does cache integrity checks when CONFIG_DEBUG_VM is defined. These checks interspersed with the regular code path has lead to compile time warnings when compiled without CONFIG_DEBUG_VM defined. Restructuring the code to move the integrity checks in to a new function would eliminate the current compile warning problem and also will allow for future changes to the debug only code to evolve without introducing new warnings in the regular path. This restructuring work is based on the discussion in the following thread: https://lkml.org/lkml/2012/7/13/424 [akpm@linux-foundation.org: fix build, cleanup] Signed-off-by: Shuah Khan <shuah.khan@hp.com> Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16Revert "mm/slab_common.c: cleanup"Pekka Enberg1-5/+10
This reverts commit 455ce9eb1cfa083da0def023094190aeb133855a. Andrew sent a better version. Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16slub: reduce failure of this_cpu_cmpxchg in put_cpu_partial() after unfreezingJoonsoo Kim1-0/+1
In current implementation, after unfreezing, we doesn't touch oldpage, so it remain 'NOT NULL'. When we call this_cpu_cmpxchg() with this old oldpage, this_cpu_cmpxchg() is mostly be failed. We can change value of oldpage to NULL after unfreezing, because unfreeze_partial() ensure that all the cpu partial slabs is removed from cpu partial list. In this time, we could expect that this_cpu_cmpxchg is mostly succeed. Acked-by: Christoph Lameter <cl@linux.com> Signed-off-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16slub: Take node lock during object free checksChristoph Lameter1-12/+18
Only applies to scenarios where debugging is on: Validation of slabs can currently occur while debugging information is updated from the fast paths of the allocator. This results in various races where we get false reports about slab metadata not being in order. This patch makes the fast paths take the node lock so that serialization with slab validation will occur. Causes additional slowdown in debug scenarios. Reported-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16mm/slab_common.c: cleanupAndrew Morton1-10/+5
Eliminate an ifdef and a label by moving all the CONFIG_DEBUG_VM checking inside the locked region. Cc: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16slab: do not call compound_head() in page_get_cache()Michel Lespinasse1-1/+0
page_get_cache() does not need to call compound_head(), as its unique caller virt_to_slab() already makes sure to return a head page. Additionally, removing the compound_head() call makes page_get_cache() consistent with page_get_slab(). Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-16slub: use free_page instead of put_page for freeing kmalloc allocationGlauber Costa1-1/+1
When freeing objects, the slub allocator will most of the time free empty pages by calling __free_pages(). But high-order kmalloc will be diposed by means of put_page() instead. It makes no sense to call put_page() in kernel pages that are provided by the object allocators, so we shouldn't be doing this ourselves. Aside from the consistency change, we don't change the flow too much. put_page()'s would call its dtor function, which is __free_pages. We also already do all of the Compound page tests ourselves, and the Mlock test we lose don't really matter. Signed-off-by: Glauber Costa <glommer@parallels.com> Acked-by: Christoph Lameter <cl@linux.com> CC: David Rientjes <rientjes@google.com> CC: Pekka Enberg <penberg@kernel.org> Signed-off-by: Pekka Enberg <penberg@kernel.org>
2012-08-02mm: remove node_start_pfn checking in new WARN_ON for nowLinus Torvalds1-1/+1
Borislav Petkov reports that the new warning added in commit 88fdf75d1bb5 ("mm: warn if pg_data_t isn't initialized with zero") triggers for him, and it is the node_start_pfn field that has already been initialized once. The call trace looks like this: x86_64_start_kernel -> x86_64_start_reservations -> start_kernel -> setup_arch -> paging_init -> zone_sizes_init -> free_area_init_nodes -> free_area_init_node and (with the warning replaced by debug output), Borislav sees On node 0 totalpages: 4193848 DMA zone: 64 pages used for memmap DMA zone: 6 pages reserved DMA zone: 3890 pages, LIFO batch:0 DMA32 zone: 16320 pages used for memmap DMA32 zone: 798464 pages, LIFO batch:31 Normal zone: 52736 pages used for memmap Normal zone: 3322368 pages, LIFO batch:31 free_area_init_node: pgdat->node_start_pfn: 4423680 <---- On node 1 totalpages: 4194304 Normal zone: 65536 pages used for memmap Normal zone: 4128768 pages, LIFO batch:31 free_area_init_node: pgdat->node_start_pfn: 8617984 <---- On node 2 totalpages: 4194304 Normal zone: 65536 pages used for memmap Normal zone: 4128768 pages, LIFO batch:31 free_area_init_node: pgdat->node_start_pfn: 12812288 <---- On node 3 totalpages: 4194304 Normal zone: 65536 pages used for memmap Normal zone: 4128768 pages, LIFO batch:31 so remove the bogus warning for now to avoid annoying people. Minchan Kim is looking at it. Reported-by: Borislav Petkov <bp@amd64.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds3-11/+40
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-08-01Merge branch 'for-3.6/core' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+7
Pull core block IO bits from Jens Axboe: "The most complicated part if this is the request allocation rework by Tejun, which has been queued up for a long time and has been in for-next ditto as well. There are a few commits from yesterday and today, mostly trivial and obvious fixes. So I'm pretty confident that it is sound. It's also smaller than usual." * 'for-3.6/core' of git://git.kernel.dk/linux-block: block: remove dead func declaration block: add partition resize function to blkpg ioctl block: uninitialized ioc->nr_tasks triggers WARN_ON block: do not artificially constrain max_sectors for stacking drivers blkcg: implement per-blkg request allocation block: prepare for multiple request_lists block: add q->nr_rqs[] and move q->rq.elvpriv to q->nr_rqs_elvpriv blkcg: inline bio_blkcg() and friends block: allocate io_context upfront block: refactor get_request[_wait]() block: drop custom queue draining used by scsi_transport_{iscsi|fc} mempool: add @gfp_mask to mempool_create_node() blkcg: make root blkcg allocation use %GFP_KERNEL blkcg: __blkg_lookup_create() doesn't need radix preload
2012-08-01Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds35-770/+2043
Merge Andrew's second set of patches: - MM - a few random fixes - a couple of RTC leftovers * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (120 commits) rtc/rtc-88pm80x: remove unneed devm_kfree rtc/rtc-88pm80x: assign ret only when rtc_register_driver fails mm: hugetlbfs: close race during teardown of hugetlbfs shared page tables tmpfs: distribute interleave better across nodes mm: remove redundant initialization mm: warn if pg_data_t isn't initialized with zero mips: zero out pg_data_t when it's allocated memcg: gix memory accounting scalability in shrink_page_list mm/sparse: remove index_init_lock mm/sparse: more checks on mem_section number mm/sparse: optimize sparse_index_alloc memcg: add mem_cgroup_from_css() helper memcg: further prevent OOM with too many dirty pages memcg: prevent OOM with too many dirty pages mm: mmu_notifier: fix freed page still mapped in secondary MMU mm: memcg: only check anon swapin page charges for swap cache mm: memcg: only check swap cache pages for repeated charging mm: memcg: split swapin charge function into private and public part mm: memcg: remove needless !mm fixup to init_mm when charging mm: memcg: remove unneeded shmem charge type ...
2012-08-01mm: hugetlbfs: close race during teardown of hugetlbfs shared page tablesMel Gorman2-3/+27
If a process creates a large hugetlbfs mapping that is eligible for page table sharing and forks heavily with children some of whom fault and others which destroy the mapping then it is possible for page tables to get corrupted. Some teardowns of the mapping encounter a "bad pmd" and output a message to the kernel log. The final teardown will trigger a BUG_ON in mm/filemap.c. This was reproduced in 3.4 but is known to have existed for a long time and goes back at least as far as 2.6.37. It was probably was introduced in 2.6.20 by [39dde65c: shared page table for hugetlb page]. The messages look like this; [ ..........] Lots of bad pmd messages followed by this [ 127.164256] mm/memory.c:391: bad pmd ffff880412e04fe8(80000003de4000e7). [ 127.164257] mm/memory.c:391: bad pmd ffff880412e04ff0(80000003de6000e7). [ 127.164258] mm/memory.c:391: bad pmd ffff880412e04ff8(80000003de0000e7). [ 127.186778] ------------[ cut here ]------------ [ 127.186781] kernel BUG at mm/filemap.c:134! [ 127.186782] invalid opcode: 0000 [#1] SMP [ 127.186783] CPU 7 [ 127.186784] Modules linked in: af_packet cpufreq_conservative cpufreq_userspace cpufreq_powersave acpi_cpufreq mperf ext3 jbd dm_mod coretemp crc32c_intel usb_storage ghash_clmulni_intel aesni_intel i2c_i801 r8169 mii uas sr_mod cdrom sg iTCO_wdt iTCO_vendor_support shpchp serio_raw cryptd aes_x86_64 e1000e pci_hotplug dcdbas aes_generic container microcode ext4 mbcache jbd2 crc16 sd_mod crc_t10dif i915 drm_kms_helper drm i2c_algo_bit ehci_hcd ahci libahci usbcore rtc_cmos usb_common button i2c_core intel_agp video intel_gtt fan processor thermal thermal_sys hwmon ata_generic pata_atiixp libata scsi_mod [ 127.186801] [ 127.186802] Pid: 9017, comm: hugetlbfs-test Not tainted 3.4.0-autobuild #53 Dell Inc. OptiPlex 990/06D7TR [ 127.186804] RIP: 0010:[<ffffffff810ed6ce>] [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186809] RSP: 0000:ffff8804144b5c08 EFLAGS: 00010002 [ 127.186810] RAX: 0000000000000001 RBX: ffffea000a5c9000 RCX: 00000000ffffffc0 [ 127.186811] RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff88042dfdad00 [ 127.186812] RBP: ffff8804144b5c18 R08: 0000000000000009 R09: 0000000000000003 [ 127.186813] R10: 0000000000000000 R11: 000000000000002d R12: ffff880412ff83d8 [ 127.186814] R13: ffff880412ff83d8 R14: 0000000000000000 R15: ffff880412ff83d8 [ 127.186815] FS: 00007fe18ed2c700(0000) GS:ffff88042dce0000(0000) knlGS:0000000000000000 [ 127.186816] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b [ 127.186817] CR2: 00007fe340000503 CR3: 0000000417a14000 CR4: 00000000000407e0 [ 127.186818] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 127.186819] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 127.186820] Process hugetlbfs-test (pid: 9017, threadinfo ffff8804144b4000, task ffff880417f803c0) [ 127.186821] Stack: [ 127.186822] ffffea000a5c9000 0000000000000000 ffff8804144b5c48 ffffffff810ed83b [ 127.186824] ffff8804144b5c48 000000000000138a 0000000000001387 ffff8804144b5c98 [ 127.186825] ffff8804144b5d48 ffffffff811bc925 ffff8804144b5cb8 0000000000000000 [ 127.186827] Call Trace: [ 127.186829] [<ffffffff810ed83b>] delete_from_page_cache+0x3b/0x80 [ 127.186832] [<ffffffff811bc925>] truncate_hugepages+0x115/0x220 [ 127.186834] [<ffffffff811bca43>] hugetlbfs_evict_inode+0x13/0x30 [ 127.186837] [<ffffffff811655c7>] evict+0xa7/0x1b0 [ 127.186839] [<ffffffff811657a3>] iput_final+0xd3/0x1f0 [ 127.186840] [<ffffffff811658f9>] iput+0x39/0x50 [ 127.186842] [<ffffffff81162708>] d_kill+0xf8/0x130 [ 127.186843] [<ffffffff81162812>] dput+0xd2/0x1a0 [ 127.186845] [<ffffffff8114e2d0>] __fput+0x170/0x230 [ 127.186848] [<ffffffff81236e0e>] ? rb_erase+0xce/0x150 [ 127.186849] [<ffffffff8114e3ad>] fput+0x1d/0x30 [ 127.186851] [<ffffffff81117db7>] remove_vma+0x37/0x80 [ 127.186853] [<ffffffff81119182>] do_munmap+0x2d2/0x360 [ 127.186855] [<ffffffff811cc639>] sys_shmdt+0xc9/0x170 [ 127.186857] [<ffffffff81410a39>] system_call_fastpath+0x16/0x1b [ 127.186858] Code: 0f 1f 44 00 00 48 8b 43 08 48 8b 00 48 8b 40 28 8b b0 40 03 00 00 85 f6 0f 88 df fe ff ff 48 89 df e8 e7 cb 05 00 e9 d2 fe ff ff <0f> 0b 55 83 e2 fd 48 89 e5 48 83 ec 30 48 89 5d d8 4c 89 65 e0 [ 127.186868] RIP [<ffffffff810ed6ce>] __delete_from_page_cache+0x15e/0x160 [ 127.186870] RSP <ffff8804144b5c08> [ 127.186871] ---[ end trace 7cbac5d1db69f426 ]--- The bug is a race and not always easy to reproduce. To reproduce it I was doing the following on a single socket I7-based machine with 16G of RAM. $ hugeadm --pool-pages-max DEFAULT:13G $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmmax $ echo $((18*1048576*1024)) > /proc/sys/kernel/shmall $ for i in `seq 1 9000`; do ./hugetlbfs-test; done On my particular machine, it usually triggers within 10 minutes but enabling debug options can change the timing such that it never hits. Once the bug is triggered, the machine is in trouble and needs to be rebooted. The machine will respond but processes accessing proc like "ps aux" will hang due to the BUG_ON. shutdown will also hang and needs a hard reset or a sysrq-b. The basic problem is a race between page table sharing and teardown. For the most part page table sharing depends on i_mmap_mutex. In some cases, it is also taking the mm->page_table_lock for the PTE updates but with shared page tables, it is the i_mmap_mutex that is more important. Unfortunately it appears to be also insufficient. Consider the following situation Process A Process B --------- --------- hugetlb_fault shmdt LockWrite(mmap_sem) do_munmap unmap_region unmap_vmas unmap_single_vma unmap_hugepage_range Lock(i_mmap_mutex) Lock(mm->page_table_lock) huge_pmd_unshare/unmap tables <--- (1) Unlock(mm->page_table_lock) Unlock(i_mmap_mutex) huge_pte_alloc ... Lock(i_mmap_mutex) ... vma_prio_walk, find svma, spte ... Lock(mm->page_table_lock) ... share spte ... Unlock(mm->page_table_lock) ... Unlock(i_mmap_mutex) ... hugetlb_no_page <--- (2) free_pgtables unlink_file_vma hugetlb_free_pgd_range remove_vma_list In this scenario, it is possible for Process A to share page tables with Process B that is trying to tear them down. The i_mmap_mutex on its own does not prevent Process A walking Process B's page tables. At (1) above, the page tables are not shared yet so it unmaps the PMDs. Process A sets up page table sharing and at (2) faults a new entry. Process B then trips up on it in free_pgtables. This patch fixes the problem by adding a new function __unmap_hugepage_range_final that is only called when the VMA is about to be destroyed. This function clears VM_MAYSHARE during unmap_hugepage_range() under the i_mmap_mutex. This makes the VMA ineligible for sharing and avoids the race. Superficially this looks like it would then be vunerable to truncate and madvise issues but hugetlbfs has its own truncate handlers so does not use unmap_mapping_range() and does not support madvise(DONTNEED). This should be treated as a -stable candidate if it is merged. Test program is as follows. The test case was mostly written by Michal Hocko with a few minor changes to reproduce this bug. ==== CUT HERE ==== static size_t huge_page_size = (2UL << 20); static size_t nr_huge_page_A = 512; static size_t nr_huge_page_B = 5632; unsigned int get_random(unsigned int max) { struct timeval tv; gettimeofday(&tv, NULL); srandom(tv.tv_usec); return random() % max; } static void play(void *addr, size_t size) { unsigned char *start = addr, *end = start + size, *a; start += get_random(size/2); /* we could itterate on huge pages but let's give it more time. */ for (a = start; a < end; a += 4096) *a = 0; } int main(int argc, char **argv) { key_t key = IPC_PRIVATE; size_t sizeA = nr_huge_page_A * huge_page_size; size_t sizeB = nr_huge_page_B * huge_page_size; int shmidA, shmidB; void *addrA = NULL, *addrB = NULL; int nr_children = 300, n = 0; if ((shmidA = shmget(key, sizeA, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrA = shmat(shmidA, addrA, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } if ((shmidB = shmget(key, sizeB, IPC_CREAT|SHM_HUGETLB|0660)) == -1) { perror("shmget:"); return 1; } if ((addrB = shmat(shmidB, addrB, SHM_R|SHM_W)) == (void *)-1UL) { perror("shmat"); return 1; } fork_child: switch(fork()) { case 0: switch (n%3) { case 0: play(addrA, sizeA); break; case 1: play(addrB, sizeB); break; case 2: break; } break; case -1: perror("fork:"); break; default: if (++n < nr_children) goto fork_child; play(addrA, sizeA); break; } shmdt(addrA); shmdt(addrB); do { wait(NULL); } while (--n > 0); shmctl(shmidA, IPC_RMID, NULL); shmctl(shmidB, IPC_RMID, NULL); return 0; } [akpm@linux-foundation.org: name the declaration's args, fix CONFIG_HUGETLBFS=n build] Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01tmpfs: distribute interleave better across nodesNathan Zimmer1-2/+4
When tmpfs has the interleave memory policy, it always starts allocating for each file from node 0 at offset 0. When there are many small files, the lower nodes fill up disproportionately. This patch spreads out node usage by starting files at nodes other than 0, by using the inode number to bias the starting node for interleave. Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Nick Piggin <npiggin@gmail.com> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Rik van Riel <riel@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: remove redundant initializationMinchan Kim1-7/+2
pg_data_t is zeroed before reaching free_area_init_core(), so remove the now unnecessary initializations. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: warn if pg_data_t isn't initialized with zeroMinchan Kim1-0/+3
Warn if memory-hotplug/boot code doesn't initialize pg_data_t with zero when it is allocated. Arch code and memory hotplug already initiailize pg_data_t. So this warning should never happen. I select fields randomly near the beginning, middle and end of pg_data_t for checking. This patch isn't for performance but for removing initialization code which is necessary to add whenever we adds new field to pg_data_t or zone. Firstly, Andrew suggested clearing out of pg_data_t in MM core part but Tejun doesn't like it because in the future, some archs can initialize some fields in arch code and pass them into general MM part so blindly clearing it out in mm core part would be very annoying. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01memcg: gix memory accounting scalability in shrink_page_listTim Chen1-0/+2
I noticed in a multi-process parallel files reading benchmark I ran on a 8 socket machine, throughput slowed down by a factor of 8 when I ran the benchmark within a cgroup container. I traced the problem to the following code path (see below) when we are trying to reclaim memory from file cache. The res_counter_uncharge function is called on every page that's reclaimed and created heavy lock contention. The patch below allows the reclaimed pages to be uncharged from the resource counter in batch and recovered the regression. Tim 40.67% usemem [kernel.kallsyms] [k] _raw_spin_lock | --- _raw_spin_lock | |--92.61%-- res_counter_uncharge | | | |--100.00%-- __mem_cgroup_uncharge_common | | | | | |--100.00%-- mem_cgroup_uncharge_cache_page | | | __remove_mapping | | | shrink_page_list | | | shrink_inactive_list | | | shrink_mem_cgroup_zone | | | shrink_zone | | | do_try_to_free_pages | | | try_to_free_pages | | | __alloc_pages_nodemask | | | alloc_pages_current Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.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>
2012-08-01mm/sparse: remove index_init_lockGavin Shan1-13/+1
sparse_index_init() uses the index_init_lock spinlock to protect root mem_section assignment. The lock is not necessary anymore because the function is called only during boot (during paging init which is executed only from a single CPU) and from the hotplug code (by add_memory() via arch_add_memory()) which uses mem_hotplug_mutex. The lock was introduced by 28ae55c9 ("sparsemem extreme: hotplug preparation") and sparse_index_init() was used only during boot at that time. Later when the hotplug code (and add_memory()) was introduced there was no synchronization so it was possible to online more sections from the same root probably (though I am not 100% sure about that). The first synchronization has been added by 6ad696d2 ("mm: allow memory hotplug and hibernation in the same kernel") which was later replaced by the mem_hotplug_mutex - 20d6c96b ("mem-hotplug: introduce {un}lock_memory_hotplug()"). Let's remove the lock as it is not needed and it makes the code more confusing. [mhocko@suse.cz: changelog] Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm/sparse: more checks on mem_section numberGavin Shan1-0/+2
__section_nr() was implemented to retrieve the corresponding memory section number according to its descriptor. It's possible that the specified memory section descriptor doesn't exist in the global array. So add more checking on that and report an error for a wrong case. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Acked-by: David Rientjes <rientjes@google.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>
2012-08-01mm/sparse: optimize sparse_index_allocGavin Shan1-6/+4
With CONFIG_SPARSEMEM_EXTREME, the two levels of memory section descriptors are allocated from slab or bootmem. When allocating from slab, let slab/bootmem allocator clear the memory chunk. We needn't clear it explicitly. Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01memcg: add mem_cgroup_from_css() helperWanpeng Li1-8/+11
Add a mem_cgroup_from_css() helper to replace open-coded invokations of container_of(). To clarify the code and to add a little more type safety. [akpm@linux-foundation.org: fix extensive breakage] Signed-off-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Gavin Shan <shangw@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2012-08-01memcg: further prevent OOM with too many dirty pagesHugh Dickins1-9/+24
The may_enter_fs test turns out to be too restrictive: though I saw no problem with it when testing on 3.5-rc6, it very soon OOMed when I tested on 3.5-rc6-mm1. I don't know what the difference there is, perhaps I just slightly changed the way I started off the testing: dd if=/dev/zero of=/mnt/temp bs=1M count=1024; rm -f /mnt/temp; sync repeatedly, in 20M memory.limit_in_bytes cgroup to ext4 on USB stick. ext4 (and gfs2 and xfs) turn out to allocate new pages for writing with AOP_FLAG_NOFS: that seems a little worrying, and it's unclear to me why the transaction needs to be started even before allocating pagecache memory. But it may not be worth worrying about these days: if direct reclaim avoids FS writeback, does __GFP_FS now mean anything? Anyway, we insisted on the may_enter_fs test to avoid hangs with the loop device; but since that also masks off __GFP_IO, we can test for __GFP_IO directly, ignoring may_enter_fs and __GFP_FS. But even so, the test still OOMs sometimes: when originally testing on 3.5-rc6, it OOMed about one time in five or ten; when testing just now on 3.5-rc6-mm1, it OOMed on the first iteration. This residual problem comes from an accumulation of pages under ordinary writeback, not marked PageReclaim, so rightly not causing the memcg check to wait on their writeback: these too can prevent shrink_page_list() from freeing any pages, so many times that memcg reclaim fails and OOMs. Deal with these in the same way as direct reclaim now deals with dirty FS pages: mark them PageReclaim. It is appropriate to rotate these to tail of list when writepage completes, but more importantly, the PageReclaim flag makes memcg reclaim wait on them if encountered again. Increment NR_VMSCAN_IMMEDIATE? That's arguable: I chose not. Setting PageReclaim here may occasionally race with end_page_writeback() clearing it: lru_deactivate_fn() already faced the same race, and correctly concluded that the window is small and the issue non-critical. With these changes, the test runs indefinitely without OOMing on ext4, ext3 and ext2: I'll move on to test with other filesystems later. Trivia: invert conditions for a clearer block without an else, and goto keep_locked to do the unlock_page. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01memcg: prevent OOM with too many dirty pagesMichal Hocko1-3/+20
The current implementation of dirty pages throttling is not memcg aware which makes it easy to have memcg LRUs full of dirty pages. Without throttling, these LRUs can be scanned faster than the rate of writeback, leading to memcg OOM conditions when the hard limit is small. This patch fixes the problem by throttling the allocating process (possibly a writer) during the hard limit reclaim by waiting on PageReclaim pages. We are waiting only for PageReclaim pages because those are the pages that made one full round over LRU and that means that the writeback is much slower than scanning. The solution is far from being ideal - long term solution is memcg aware dirty throttling - but it is meant to be a band aid until we have a real fix. We are seeing this happening during nightly backups which are placed into containers to prevent from eviction of the real working set. The change affects only memcg reclaim and only when we encounter PageReclaim pages which is a signal that the reclaim doesn't catch up on with the writers so somebody should be throttled. This could be potentially unfair because it could be somebody else from the group who gets throttled on behalf of the writer but as writers need to allocate as well and they allocate in higher rate the probability that only innocent processes would be penalized is not that high. I have tested this change by a simple dd copying /dev/zero to tmpfs or ext3 running under small memcg (1G copy under 5M, 60M, 300M and 2G containers) and dd got killed by OOM killer every time. With the patch I could run the dd with the same size under 5M controller without any OOM. The issue is more visible with slower devices for output. * With the patch ================ * tmpfs size=2G --------------- $ vim cgroup_cache_oom_test.sh $ ./cgroup_cache_oom_test.sh 5M using Limit 5M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 30.4049 s, 34.5 MB/s $ ./cgroup_cache_oom_test.sh 60M using Limit 60M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 31.4561 s, 33.3 MB/s $ ./cgroup_cache_oom_test.sh 300M using Limit 300M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 20.4618 s, 51.2 MB/s $ ./cgroup_cache_oom_test.sh 2G using Limit 2G for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 1.42172 s, 738 MB/s * ext3 ------ $ ./cgroup_cache_oom_test.sh 5M using Limit 5M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 27.9547 s, 37.5 MB/s $ ./cgroup_cache_oom_test.sh 60M using Limit 60M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 30.3221 s, 34.6 MB/s $ ./cgroup_cache_oom_test.sh 300M using Limit 300M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 24.5764 s, 42.7 MB/s $ ./cgroup_cache_oom_test.sh 2G using Limit 2G for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 3.35828 s, 312 MB/s * Without the patch =================== * tmpfs size=2G --------------- $ ./cgroup_cache_oom_test.sh 5M using Limit 5M for group ./cgroup_cache_oom_test.sh: line 46: 4668 Killed dd if=/dev/zero of=$OUT/zero bs=1M count=$count $ ./cgroup_cache_oom_test.sh 60M using Limit 60M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 25.4989 s, 41.1 MB/s $ ./cgroup_cache_oom_test.sh 300M using Limit 300M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 24.3928 s, 43.0 MB/s $ ./cgroup_cache_oom_test.sh 2G using Limit 2G for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 1.49797 s, 700 MB/s * ext3 ------ $ ./cgroup_cache_oom_test.sh 5M using Limit 5M for group ./cgroup_cache_oom_test.sh: line 46: 4689 Killed dd if=/dev/zero of=$OUT/zero bs=1M count=$count $ ./cgroup_cache_oom_test.sh 60M using Limit 60M for group ./cgroup_cache_oom_test.sh: line 46: 4692 Killed dd if=/dev/zero of=$OUT/zero bs=1M count=$count $ ./cgroup_cache_oom_test.sh 300M using Limit 300M for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 20.248 s, 51.8 MB/s $ ./cgroup_cache_oom_test.sh 2G using Limit 2G for group 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 2.85201 s, 368 MB/s [akpm@linux-foundation.org: tweak changelog, reordered the test to optimize for CONFIG_CGROUP_MEM_RES_CTLR=n] [hughd@google.com: fix deadlock with loop driver] Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujtisu.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Rik van Riel <riel@redhat.com> Cc: Ying Han <yinghan@google.com> Cc: Greg Thelen <gthelen@google.com> Cc: Hugh Dickins <hughd@google.com> Reviewed-by: Mel Gorman <mgorman@suse.de> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Michal Hocko <mhocko@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: mmu_notifier: fix freed page still mapped in secondary MMUXiao Guangrong1-22/+23
mmu_notifier_release() is called when the process is exiting. It will delete all the mmu notifiers. But at this time the page belonging to the process is still present in page tables and is present on the LRU list, so this race will happen: CPU 0 CPU 1 mmu_notifier_release: try_to_unmap: hlist_del_init_rcu(&mn->hlist); ptep_clear_flush_notify: mmu nofifler not found free page !!!!!! /* * At the point, the page has been * freed, but it is still mapped in * the secondary MMU. */ mn->ops->release(mn, mm); Then the box is not stable and sometimes we can get this bug: [ 738.075923] BUG: Bad page state in process migrate-perf pfn:03bec [ 738.075931] page:ffffea00000efb00 count:0 mapcount:0 mapping: (null) index:0x8076 [ 738.075936] page flags: 0x20000000000014(referenced|dirty) The same issue is present in mmu_notifier_unregister(). We can call ->release before deleting the notifier to ensure the page has been unmapped from the secondary MMU before it is freed. Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Cc: Avi Kivity <avi@redhat.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: only check anon swapin page charges for swap cacheJohannes Weiner1-8/+14
shmem knows for sure that the page is in swap cache when attempting to charge a page, because the cache charge entry function has a check for it. Only anon pages may be removed from swap cache already when trying to charge their swapin. Adjust the comment, though: '4969c11 mm: fix swapin race condition' added a stable PageSwapCache check under the page lock in the do_swap_page() before calling the memory controller, so it's unuse_pte()'s pte_same() that may fail. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: only check swap cache pages for repeated chargingJohannes Weiner1-5/+12
Only anon and shmem pages in the swap cache are attempted to be charged multiple times, from every swap pte fault or from shmem_unuse(). No other pages require checking PageCgroupUsed(). Charging pages in the swap cache is also serialized by the page lock, and since both the try_charge and commit_charge are called under the same page lock section, the PageCgroupUsed() check might as well happen before the counter charging, let alone reclaim. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: split swapin charge function into private and public partJohannes Weiner1-9/+15
When shmem is charged upon swapin, it does not need to check twice whether the memory controller is enabled. Also, shmem pages do not have to be checked for everything that regular anon pages have to be checked for, so let shmem use the internal version directly and allow future patches to move around checks that are only required when swapping in anon pages. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: remove needless !mm fixup to init_mm when chargingJohannes Weiner1-6/+1
It does not matter to __mem_cgroup_try_charge() if the passed mm is NULL or init_mm, it will charge the root memcg in either case. Also fix up the comment in __mem_cgroup_try_charge() that claimed the init_mm would be charged when no mm was passed. It's not really incorrect, but confusing. Clarify that the root memcg is charged in this case. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: remove unneeded shmem charge typeJohannes Weiner1-10/+1
shmem page charges have not needed a separate charge type to tell them from regular file pages since 08e552c ("memcg: synchronized LRU"). Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: move swapin charge functions above callsitesJohannes Weiner1-36/+32
Charging cache pages may require swapin in the shmem case. Save the forward declaration and just move the swapin functions above the cache charging functions. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: only check for PageSwapCache when uncharging anonJohannes Weiner1-9/+4
Only anon pages that are uncharged at the time of the last page table mapping vanishing may be in swapcache. When shmem pages, file pages, swap-freed anon pages, or just migrated pages are uncharged, they are known for sure to be not in swapcache. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: push down PageSwapCache check into uncharge entry functionsJohannes Weiner1-6/+12
Not all uncharge paths need to check if the page is swapcache, some of them can know for sure. Push down the check into all callsites of uncharge_common() so that the patch that removes some of them is more obvious. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: swapfile: clean up unuse_pte race handlingJohannes Weiner1-2/+1
The conditional mem_cgroup_cancel_charge_swapin() is a leftover from when the function would continue to reestablish the page even after mem_cgroup_try_charge_swapin() failed. After 85d9fc8 "memcg: fix refcnt handling at swapoff", the condition is always true when this code is reached. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: memcg: fix compaction/migration failing due to memcg limitsJohannes Weiner2-40/+38
Compaction (and page migration in general) can currently be hindered through pages being owned by memory cgroups that are at their limits and unreclaimable. The reason is that the replacement page is being charged against the limit while the page being replaced is also still charged. But this seems unnecessary, given that only one of the two pages will still be in use after migration finishes. This patch changes the memcg migration sequence so that the replacement page is not charged. Whatever page is still in use after successful or failed migration gets to keep the charge of the page that was going to be replaced. The replacement page will still show up temporarily in the rss/cache statistics, this can be fixed in a later patch as it's less urgent. Reported-by: David Rientjes <rientjes@google.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Wanpeng Li <liwp.linux@gmail.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01swapfile: avoid dereferencing bd_disk during swap_entry_free for network storageMel Gorman1-4/+6
Commit b3a27d ("swap: Add swap slot free callback to block_device_operations") dereferences p->bdev->bd_disk but this is a NULL dereference if using swap-over-NFS. This patch checks SWP_BLKDEV on the swap_info_struct before dereferencing. With reference to this callback, Christoph Hellwig stated "Please just remove the callback entirely. It has no user outside the staging tree and was added clearly against the rules for that staging tree". This would also be my preference but there was not an obvious way of keeping zram in staging/ happy. Signed-off-by: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: add support for direct_IO to highmem pagesMel Gorman3-3/+15
The patch "mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages" added support for using direct_IO to write swap pages but it is insufficient for highmem pages. To support highmem pages, this patch kmaps() the page before calling the direct_IO() handler. As direct_IO deals with virtual addresses an additional helper is necessary for get_kernel_pages() to lookup the struct page for a kmap virtual address. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-08-01mm: swap: implement generic handler for swap_activateMel Gorman2-86/+97
The version of swap_activate introduced is sufficient for swap-over-NFS but would not provide enough information to implement a generic handler. This patch shuffles things slightly to ensure the same information is available for aops->swap_activate() as is available to the core. No functionality change. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: David S. Miller <davem@davemloft.net> Cc: Eric B Munson <emunson@mgebm.net> Cc: Eric Paris <eparis@redhat.com> Cc: James Morris <jmorris@namei.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Christie <michaelc@cs.wisc.edu> Cc: Neil Brown <neilb@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sebastian Andrzej Siewior <sebastian@breakpoint.cc> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: Xiaotian Feng <dfeng@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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