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2012-02-24NOMMU: Don't need to clear vm_mm when deleting a VMADavid Howells1-2/+0
Don't clear vm_mm in a deleted VMA as it's unnecessary and might conceivably break the filesystem or driver VMA close routine. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-24NOMMU: Lock i_mmap_mutex for access to the VMA prio listDavid Howells1-0/+7
Lock i_mmap_mutex for access to the VMA prio list to prevent concurrent access. Currently, certain parts of the mmap handling are protected by the region mutex, but not all. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-24mm: memcg: Correct unregistring of events attached to the same eventfdAnton Vorontsov1-1/+4
There is an issue when memcg unregisters events that were attached to the same eventfd: - On the first call mem_cgroup_usage_unregister_event() removes all events attached to a given eventfd, and if there were no events left, thresholds->primary would become NULL; - Since there were several events registered, cgroups core will call mem_cgroup_usage_unregister_event() again, but now kernel will oops, as the function doesn't expect that threshold->primary may be NULL. That's a good question whether mem_cgroup_usage_unregister_event() should actually remove all events in one go, but nowadays it can't do any better as cftype->unregister_event callback doesn't pass any private event-associated cookie. So, let's fix the issue by simply checking for threshold->primary. FWIW, w/o the patch the following oops may be observed: BUG: unable to handle kernel NULL pointer dereference at 0000000000000004 IP: [<ffffffff810be32c>] mem_cgroup_usage_unregister_event+0x9c/0x1f0 Pid: 574, comm: kworker/0:2 Not tainted 3.3.0-rc4+ #9 Bochs Bochs RIP: 0010:[<ffffffff810be32c>] [<ffffffff810be32c>] mem_cgroup_usage_unregister_event+0x9c/0x1f0 RSP: 0018:ffff88001d0b9d60 EFLAGS: 00010246 Process kworker/0:2 (pid: 574, threadinfo ffff88001d0b8000, task ffff88001de91cc0) Call Trace: [<ffffffff8107092b>] cgroup_event_remove+0x2b/0x60 [<ffffffff8103db94>] process_one_work+0x174/0x450 [<ffffffff8103e413>] worker_thread+0x123/0x2d0 Cc: stable <stable@vger.kernel.org> Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-13vfs: fix panic in __d_lookup() with high dentry hashtable countsDimitri Sivanich1-0/+1
When the number of dentry cache hash table entries gets too high (2147483648 entries), as happens by default on a 16TB system, use of a signed integer in the dcache_init() initialization loop prevents the dentry_hashtable from getting initialized, causing a panic in __d_lookup(). Fix this in dcache_init() and similar areas. Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Acked-by: David S. Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-10Merge tag 'writeback-fixes' of ↵Linus Torvalds1-5/+18
git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux fix 1 mysterious divide error fix 3 NULL dereference bugs in writeback tracing, on SD card removal w/o umount * tag 'writeback-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/wfg/linux: writeback: fix dereferencing NULL bdi->dev on trace_writeback_queue lib: proportion: lower PROP_MAX_SHIFT to 32 on 64-bit kernel writeback: fix NULL bdi->dev in trace writeback_single_inode backing-dev: fix wakeup timer races with bdi_unregister()
2012-02-08mm: fix UP THP spin_is_locked BUGsHugh Dickins2-3/+3
Fix CONFIG_TRANSPARENT_HUGEPAGE=y CONFIG_SMP=n CONFIG_DEBUG_VM=y CONFIG_DEBUG_SPINLOCK=n kernel: spin_is_locked() is then always false, and so triggers some BUGs in Transparent HugePage codepaths. asm-generic/bug.h mentions this problem, and provides a WARN_ON_SMP(x); but being too lazy to add VM_BUG_ON_SMP, BUG_ON_SMP, WARN_ON_SMP_ONCE, VM_WARN_ON_SMP_ONCE, just test NR_CPUS != 1 in the existing VM_BUG_ONs. Signed-off-by: Hugh Dickins <hughd@google.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>
2012-02-08mm: compaction: check for overlapping nodes during isolation for migrationMel Gorman1-1/+10
When isolating pages for migration, migration starts at the start of a zone while the free scanner starts at the end of the zone. Migration avoids entering a new zone by never going beyond the free scanned. Unfortunately, in very rare cases nodes can overlap. When this happens, migration isolates pages without the LRU lock held, corrupting lists which will trigger errors in reclaim or during page free such as in the following oops BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: [<ffffffff810f795c>] free_pcppages_bulk+0xcc/0x450 PGD 1dda554067 PUD 1e1cb58067 PMD 0 Oops: 0000 [#1] SMP CPU 37 Pid: 17088, comm: memcg_process_s Tainted: G X RIP: free_pcppages_bulk+0xcc/0x450 Process memcg_process_s (pid: 17088, threadinfo ffff881c2926e000, task ffff881c2926c0c0) Call Trace: free_hot_cold_page+0x17e/0x1f0 __pagevec_free+0x90/0xb0 release_pages+0x22a/0x260 pagevec_lru_move_fn+0xf3/0x110 putback_lru_page+0x66/0xe0 unmap_and_move+0x156/0x180 migrate_pages+0x9e/0x1b0 compact_zone+0x1f3/0x2f0 compact_zone_order+0xa2/0xe0 try_to_compact_pages+0xdf/0x110 __alloc_pages_direct_compact+0xee/0x1c0 __alloc_pages_slowpath+0x370/0x830 __alloc_pages_nodemask+0x1b1/0x1c0 alloc_pages_vma+0x9b/0x160 do_huge_pmd_anonymous_page+0x160/0x270 do_page_fault+0x207/0x4c0 page_fault+0x25/0x30 The "X" in the taint flag means that external modules were loaded but but is unrelated to the bug triggering. The real problem was because the PFN layout looks like this Zone PFN ranges: DMA 0x00000010 -> 0x00001000 DMA32 0x00001000 -> 0x00100000 Normal 0x00100000 -> 0x01e80000 Movable zone start PFN for each node early_node_map[14] active PFN ranges 0: 0x00000010 -> 0x0000009b 0: 0x00000100 -> 0x0007a1ec 0: 0x0007a354 -> 0x0007a379 0: 0x0007f7ff -> 0x0007f800 0: 0x00100000 -> 0x00680000 1: 0x00680000 -> 0x00e80000 0: 0x00e80000 -> 0x01080000 1: 0x01080000 -> 0x01280000 0: 0x01280000 -> 0x01480000 1: 0x01480000 -> 0x01680000 0: 0x01680000 -> 0x01880000 1: 0x01880000 -> 0x01a80000 0: 0x01a80000 -> 0x01c80000 1: 0x01c80000 -> 0x01e80000 The fix is straight-forward. isolate_migratepages() has to make a similar check to isolate_freepage to ensure that it never isolates pages from a zone it does not hold the LRU lock for. This was discovered in a 3.0-based kernel but it affects 3.1.x, 3.2.x and current mainline. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-04Merge branch 'akpm'Linus Torvalds5-7/+26
* akpm: mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block during isolation for migration readahead: fix pipeline break caused by block plug kprobes: fix a memory leak in function pre_handler_kretprobe() drivers/tty/vt/vt_ioctl.c: fix KDFONTOP 32bit compatibility layer lkdtm: avoid calling lkdtm_do_action() with spinlock held mm/filemap_xip.c: fix race condition in xip_file_fault() mm/memcontrol.c: fix warning with CONFIG_NUMA=n avr32: select generic atomic64_t support mm: postpone migrated page mapping reset xtensa: fix memscan() MAINTAINERS: update lguest F: patterns MAINTAINERS: remove staging sections MAINTAINERS: remove iMX5 section MAINTAINERS: update partitions block F: patterns
2012-02-03mm: compaction: check pfn_valid when entering a new MAX_ORDER_NR_PAGES block ↵Mel Gorman1-0/+13
during isolation for migration When isolating for migration, migration starts at the start of a zone which is not necessarily pageblock aligned. Further, it stops isolating when COMPACT_CLUSTER_MAX pages are isolated so migrate_pfn is generally not aligned. This allows isolate_migratepages() to call pfn_to_page() on an invalid PFN which can result in a crash. This was originally reported against a 3.0-based kernel with the following trace in a crash dump. PID: 9902 TASK: d47aecd0 CPU: 0 COMMAND: "memcg_process_s" #0 [d72d3ad0] crash_kexec at c028cfdb #1 [d72d3b24] oops_end at c05c5322 #2 [d72d3b38] __bad_area_nosemaphore at c0227e60 #3 [d72d3bec] bad_area at c0227fb6 #4 [d72d3c00] do_page_fault at c05c72ec #5 [d72d3c80] error_code (via page_fault) at c05c47a4 EAX: 00000000 EBX: 000c0000 ECX: 00000001 EDX: 00000807 EBP: 000c0000 DS: 007b ESI: 00000001 ES: 007b EDI: f3000a80 GS: 6f50 CS: 0060 EIP: c030b15a ERR: ffffffff EFLAGS: 00010002 #6 [d72d3cb4] isolate_migratepages at c030b15a #7 [d72d3d14] zone_watermark_ok at c02d26cb #8 [d72d3d2c] compact_zone at c030b8de #9 [d72d3d68] compact_zone_order at c030bba1 #10 [d72d3db4] try_to_compact_pages at c030bc84 #11 [d72d3ddc] __alloc_pages_direct_compact at c02d61e7 #12 [d72d3e08] __alloc_pages_slowpath at c02d66c7 #13 [d72d3e78] __alloc_pages_nodemask at c02d6a97 #14 [d72d3eb8] alloc_pages_vma at c030a845 #15 [d72d3ed4] do_huge_pmd_anonymous_page at c03178eb #16 [d72d3f00] handle_mm_fault at c02f36c6 #17 [d72d3f30] do_page_fault at c05c70ed #18 [d72d3fb0] error_code (via page_fault) at c05c47a4 EAX: b71ff000 EBX: 00000001 ECX: 00001600 EDX: 00000431 DS: 007b ESI: 08048950 ES: 007b EDI: bfaa3788 SS: 007b ESP: bfaa36e0 EBP: bfaa3828 GS: 6f50 CS: 0073 EIP: 080487c8 ERR: ffffffff EFLAGS: 00010202 It was also reported by Herbert van den Bergh against 3.1-based kernel with the following snippet from the console log. BUG: unable to handle kernel paging request at 01c00008 IP: [<c0522399>] isolate_migratepages+0x119/0x390 *pdpt = 000000002f7ce001 *pde = 0000000000000000 It is expected that it also affects 3.2.x and current mainline. The problem is that pfn_valid is only called on the first PFN being checked and that PFN is not necessarily aligned. Lets say we have a case like this H = MAX_ORDER_NR_PAGES boundary | = pageblock boundary m = cc->migrate_pfn f = cc->free_pfn o = memory hole H------|------H------|----m-Hoooooo|ooooooH-f----|------H The migrate_pfn is just below a memory hole and the free scanner is beyond the hole. When isolate_migratepages started, it scans from migrate_pfn to migrate_pfn+pageblock_nr_pages which is now in a memory hole. It checks pfn_valid() on the first PFN but then scans into the hole where there are not necessarily valid struct pages. This patch ensures that isolate_migratepages calls pfn_valid when necessary. Reported-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Tested-by: Herbert van den Bergh <herbert.van.den.bergh@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-03readahead: fix pipeline break caused by block plugShaohua Li1-4/+4
Herbert Poetzl reported a performance regression since 2.6.39. The test is a simple dd read, but with big block size. The reason is: T1: ra (A, A+128k), (A+128k, A+256k) T2: lock_page for page A, submit the 256k T3: hit page A+128K, ra (A+256k, A+384). the range isn't submitted because of plug and there isn't any lock_page till we hit page A+256k because all pages from A to A+256k is in memory T4: hit page A+256k, ra (A+384, A+ 512). Because of plug, the range isn't submitted again. T5: lock_page A+256k, so (A+256k, A+512k) will be submitted. The task is waitting for (A+256k, A+512k) finish. There is no request to disk in T3 and T4, so readahead pipeline breaks. We really don't need block plug for generic_file_aio_read() for buffered I/O. The readahead already has plug and has fine grained control when I/O should be submitted. Deleting plug for buffered I/O fixes the regression. One side effect is plug makes the request size 256k, the size is 128k without it. This is because default ra size is 128k and not a reason we need plug here. Vivek said: : We submit some readahead IO to device request queue but because of nested : plug, queue never gets unplugged. When read logic reaches a page which is : not in page cache, it waits for page to be read from the disk : (lock_page_killable()) and that time we flush the plug list. : : So effectively read ahead logic is kind of broken in parts because of : nested plugging. Removing top level plug (generic_file_aio_read()) for : buffered reads, will allow unplugging queue earlier for readahead. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Reported-by: Herbert Poetzl <herbert@13thfloor.at> Tested-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Vivek Goyal <vgoyal@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>
2012-02-03mm/filemap_xip.c: fix race condition in xip_file_fault()Carsten Otte1-1/+6
Fix a race condition that shows in conjunction with xip_file_fault() when two threads of the same user process fault on the same memory page. In this case, the race winner will install the page table entry and the unlucky loser will cause an oops: xip_file_fault calls vm_insert_pfn (via vm_insert_mixed) which drops out at this check: retval = -EBUSY; if (!pte_none(*pte)) goto out_unlock; The resulting -EBUSY return value will trigger a BUG_ON() in xip_file_fault. This fix simply considers the fault as fixed in this case, because the race winner has successfully installed the pte. [akpm@linux-foundation.org: use conventional (and consistent) comment layout] Reported-by: David Sadler <dsadler@us.ibm.com> Signed-off-by: Carsten Otte <cotte@de.ibm.com> Reported-by: Louis Alex Eisner <leisner@cs.ucsd.edu> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-03mm/memcontrol.c: fix warning with CONFIG_NUMA=nAndrew Morton1-1/+2
mm/memcontrol.c: In function 'memcg_check_events': mm/memcontrol.c:779: warning: unused variable 'do_numainfo' Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Hiroyuki KAMEZAWA <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: "Kirill A. Shutemov" <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-03mm: postpone migrated page mapping resetKonstantin Khlebnikov1-1/+1
Postpone resetting page->mapping until the final remove_migration_ptes(). Otherwise the expression PageAnon(migration_entry_to_page(entry)) does not work. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: 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>
2012-02-03Merge tag 'kmemleak-fixes' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux Trivial kmemleak bug-fixes: - Early logging doesn't stop when kmemleak is off by default. - Zero-size scanning areas should be ignored (currently it prints a warning). * tag 'kmemleak-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux: kmemleak: Disable early logging when kmemleak is off by default kmemleak: Only scan non-zero-size areas
2012-02-02Fix race in process_vm_rw_coreChristopher Yeoh1-14/+9
This fixes the race in process_vm_core found by Oleg (see http://article.gmane.org/gmane.linux.kernel/1235667/ for details). This has been updated since I last sent it as the creation of the new mm_access() function did almost exactly the same thing as parts of the previous version of this patch did. In order to use mm_access() even when /proc isn't enabled, we move it to kernel/fork.c where other related process mm access functions already are. Signed-off-by: Chris Yeoh <yeohc@au1.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-02-01backing-dev: fix wakeup timer races with bdi_unregister()Rabin Vincent1-5/+18
While 7a401a972df8e18 ("backing-dev: ensure wakeup_timer is deleted") addressed the problem of the bdi being freed with a queued wakeup timer, there are other races that could happen if the wakeup timer expires after/during bdi_unregister(), before bdi_destroy() is called. wakeup_timer_fn() could attempt to wakeup a task which has already has been freed, or could access a NULL bdi->dev via the wake_forker_thread tracepoint. Cc: <stable@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Reported-by: Chanho Min <chanho.min@lge.com> Reviewed-by: Namjae Jeon <linkinjeon@gmail.com> Signed-off-by: Rabin Vincent <rabin@rab.in> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
2012-01-26Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds1-2/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Add missing __cpuinit annotation in rcutorture code sched: Add "const" to is_idle_task() parameter rcu: Make rcutorture bool parameters really bool (core code) memblock: Fix alloc failure due to dumb underflow protection in memblock_find_in_range_node()
2012-01-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-2/+2
Davem says: 1) Fix JIT code generation on x86-64 for divide by zero, from Eric Dumazet. 2) tg3 header length computation correction from Eric Dumazet. 3) More build and reference counting fixes for socket memory cgroup code from Glauber Costa. 4) module.h snuck back into a core header after all the hard work we did to remove that, from Paul Gortmaker and Jesper Dangaard Brouer. 5) Fix PHY naming regression and add some new PCI IDs in stmmac, from Alessandro Rubini. 6) Netlink message generation fix in new team driver, should only advertise the entries that changed during events, from Jiri Pirko. 7) SRIOV VF registration and unregistration fixes, and also add a missing PCI ID, from Roopa Prabhu. 8) Fix infinite loop in tx queue flush code of brcmsmac, from Stanislaw Gruszka. 9) ftgmac100/ftmac100 build fix, missing interrupt.h include. 10) Memory leak fix in net/hyperv do_set_mutlicast() handling, from Wei Yongjun. 11) Off by one fix in netem packet scheduler, from Vijay Subramanian. 12) TCP loss detection fix from Yuchung Cheng. 13) TCP reset packet MD5 calculation uses wrong address, fix from Shawn Lu. 14) skge carrier assertion and DMA mapping fixes from Stephen Hemminger. 15) Congestion recovery undo performed at the wrong spot in BIC and CUBIC congestion control modules, fix from Neal Cardwell. 16) Ethtool ETHTOOL_GSSET_INFO is unnecessarily restrictive, from Michał Mirosław. 17) Fix triggerable race in ipv6 sysctl handling, from Francesco Ruggeri. 18) Statistics bug fixes in mlx4 from Eugenia Emantayev. 19) rds locking bug fix during info dumps, from your's truly. * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (67 commits) rds: Make rds_sock_lock BH rather than IRQ safe. netprio_cgroup.h: dont include module.h from other includes net: flow_dissector.c missing include linux/export.h team: send only changed options/ports via netlink net/hyperv: fix possible memory leak in do_set_multicast() drivers/net: dsa/mv88e6xxx.c files need linux/module.h stmmac: added PCI identifiers llc: Fix race condition in llc_ui_recvmsg stmmac: fix phy naming inconsistency dsa: Add reporting of silicon revision for Marvell 88E6123/88E6161/88E6165 switches. tg3: fix ipv6 header length computation skge: add byte queue limit support mv643xx_eth: Add Rx Discard and Rx Overrun statistics bnx2x: fix compilation error with SOE in fw_dump bnx2x: handle CHIP_REVISION during init_one bnx2x: allow user to change ring size in ISCSI SD mode bnx2x: fix Big-Endianess in ethtool -t bnx2x: fixed ethtool statistics for MF modes bnx2x: credit-leakage fixup on vlan_mac_del_all macvlan: fix a possible use after free ...
2012-01-23mm: fix rss count leakage during migrationKonstantin Khlebnikov1-9/+28
Memory migration fills a pte with a migration entry and it doesn't update the rss counters. Then it replaces the migration entry with the new page (or the old one if migration failed). But between these two passes this pte can be unmaped, or a task can fork a child and it will get a copy of this migration entry. Nobody accounts for this in the rss counters. This patch properly adjust rss counters for migration entries in zap_pte_range() and copy_one_pte(). Thus we avoid extra atomic operations on the migration fast-path. Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Hugh Dickins <hughd@google.com> Cc: 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>
2012-01-23SHM_UNLOCK: fix Unevictable pages stranded after swapHugh Dickins2-94/+80
Commit cc39c6a9bbde ("mm: account skipped entries to avoid looping in find_get_pages") correctly fixed an infinite loop; but left a problem that find_get_pages() on shmem would return 0 (appearing to callers to mean end of tree) when it meets a run of nr_pages swap entries. The only uses of find_get_pages() on shmem are via pagevec_lookup(), called from invalidate_mapping_pages(), and from shmctl SHM_UNLOCK's scan_mapping_unevictable_pages(). The first is already commented, and not worth worrying about; but the second can leave pages on the Unevictable list after an unusual sequence of swapping and locking. Fix that by using shmem_find_get_pages_and_swap() (then ignoring the swap) instead of pagevec_lookup(). But I don't want to contaminate vmscan.c with shmem internals, nor shmem.c with LRU locking. So move scan_mapping_unevictable_pages() into shmem.c, renaming it shmem_unlock_mapping(); and rename check_move_unevictable_page() to check_move_unevictable_pages(), looping down an array of pages, oftentimes under the same lock. Leave out the "rotate unevictable list" block: that's a leftover from when this was used for /proc/sys/vm/scan_unevictable_pages, whose flawed handling involved looking at pages at tail of LRU. Was there significance to the sequence first ClearPageUnevictable, then test page_evictable, then SetPageUnevictable here? I think not, we're under LRU lock, and have no barriers between those. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michel Lespinasse <walken@google.com> Cc: <stable@vger.kernel.org> [back to 3.1 but will need respins] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23SHM_UNLOCK: fix long unpreemptible sectionHugh Dickins2-8/+11
scan_mapping_unevictable_pages() is used to make SysV SHM_LOCKed pages evictable again once the shared memory is unlocked. It does this with pagevec_lookup()s across the whole object (which might occupy most of memory), and takes 300ms to unlock 7GB here. A cond_resched() every PAGEVEC_SIZE pages would be good. However, KOSAKI-san points out that this is called under shmem.c's info->lock, and it's also under shm.c's shm_lock(), both spinlocks. There is no strong reason for that: we need to take these pages off the unevictable list soonish, but those locks are not required for it. So move the call to scan_mapping_unevictable_pages() from shmem.c's unlock handling up to shm.c's unlock handling. Remove the recently added barrier, not needed now we have spin_unlock() before the scan. Use get_file(), with subsequent fput(), to make sure we have a reference to mapping throughout scan_mapping_unevictable_pages(): that's something that was previously guaranteed by the shm_lock(). Remove shmctl's lru_add_drain_all(): we don't fault in pages at SHM_LOCK time, and we lazily discover them to be Unevictable later, so it serves no purpose for SHM_LOCK; and serves no purpose for SHM_UNLOCK, since pages still on pagevec are not marked Unevictable. The original code avoided redundant rescans by checking VM_LOCKED flag at its level: now avoid them by checking shp's SHM_LOCKED. The original code called scan_mapping_unevictable_pages() on a locked area at shm_destroy() time: perhaps we once had accounting cross-checks which required that, but not now, so skip the overhead and just let inode eviction deal with them. Put check_move_unevictable_page() and scan_mapping_unevictable_pages() under CONFIG_SHMEM (with stub for the TINY case when ramfs is used), more as comment than to save space; comment them used for SHM_UNLOCK. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Rik van Riel <riel@redhat.com> Cc: Shaohua Li <shaohua.li@intel.com> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23mm/hugetlb.c: undo change to page mapcount in fault handlerHillf Danton1-3/+6
Page mapcount should be updated only if we are sure that the page ends up in the page table otherwise we would leak if we couldn't COW due to reservations or if idx is out of bounds. Signed-off-by: Hillf Danton <dhillf@gmail.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> 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>
2012-01-23mm: memcg: update the correct soft limit tree during migrationJohannes Weiner1-1/+1
end_migration() passes the old page instead of the new page to commit the charge. This page descriptor is not used for committing itself, though, since we also pass the (correct) page_cgroup descriptor. But it's used to find the soft limit tree through the page's zone, so the soft limit tree of the old page's zone is updated instead of that of the new page's, which might get slightly out of date until the next charge reaches the ratelimit point. This glitch has been present since 5564e88 ("memcg: condense page_cgroup-to-page lookup points"). This fixes a bug that I introduced in 2.6.38. It's benign enough (to my knowledge) that we probably don't want this for stable. Reported-by: Hugh Dickins <hughd@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> Acked-by: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23mm: __count_immobile_pages(): make sure the node is onlineMichal Hocko1-3/+10
page_zone() requires an online node otherwise we are accessing NULL NODE_DATA. This is not an issue at the moment because node_zones are located at the structure beginning but this might change in the future so better be careful about that. Signed-off-by: Michal Hocko <mhocko@suse.cz> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-23mm: fix NULL ptr dereference in __count_immobile_pagesMichal Hocko1-0/+11
Fix the following NULL ptr dereference caused by cat /sys/devices/system/memory/memory0/removable Pid: 13979, comm: sed Not tainted 3.0.13-0.5-default #1 IBM BladeCenter LS21 -[7971PAM]-/Server Blade RIP: __count_immobile_pages+0x4/0x100 Process sed (pid: 13979, threadinfo ffff880221c36000, task ffff88022e788480) Call Trace: is_pageblock_removable_nolock+0x34/0x40 is_mem_section_removable+0x74/0xf0 show_mem_removable+0x41/0x70 sysfs_read_file+0xfe/0x1c0 vfs_read+0xc7/0x130 sys_read+0x53/0xa0 system_call_fastpath+0x16/0x1b We are crashing because we are trying to dereference NULL zone which came from pfn=0 (struct page ffffea0000000000). According to the boot log this page is marked reserved: e820 update range: 0000000000000000 - 0000000000010000 (usable) ==> (reserved) and early_node_map confirms that: early_node_map[3] active PFN ranges 1: 0x00000010 -> 0x0000009c 1: 0x00000100 -> 0x000bffa3 1: 0x00100000 -> 0x00240000 The problem is that memory_present works in PAGE_SECTION_MASK aligned blocks so the reserved range sneaks into the the section as well. This also means that free_area_init_node will not take care of those reserved pages and they stay uninitialized. When we try to read the removable status we walk through all available sections and hope that the zone is valid for all pages in the section. But this is not true in this case as the zone and nid are not initialized. We have only one node in this particular case and it is marked as node=1 (rather than 0) and that made the problem visible because page_to_nid will return 0 and there are no zones on the node. Let's check that the zone is valid and that the given pfn falls into its boundaries and mark the section not removable. This might cause some false positives, probably, but we do not have any sane way to find out whether the page is reserved by the platform or it is just not used for whatever other reasons. Signed-off-by: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-22net: fix socket memcg build with !CONFIG_NETGlauber Costa1-2/+2
There is still a build bug with the sock memcg code, that triggers with !CONFIG_NET, that survived my series of randconfig builds. Signed-off-by: Glauber Costa <glommer@parallels.com> Reported-by: Randy Dunlap <rdunlap@xenotime.net> CC: Hiroyouki Kamezawa <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-20kmemleak: Disable early logging when kmemleak is off by defaultCatalin Marinas1-0/+1
Commit b6693005 (kmemleak: When the early log buffer is exceeded, report the actual number) deferred the disabling of the early logging to kmemleak_init(). However, when CONFIG_DEBUG_KMEMLEAK_DEFAULT_OFF=y, the early logging was no longer disabled causing __init kmemleak functions to be called even after the kernel freed the init memory. This patch disables the early logging during kmemleak_init() if kmemleak is left disabled. Reported-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de> Tested-by: Dirk Gouders <gouders@et.bocholt.fh-gelsenkirchen.de> Tested-by: Josh Boyer <jwboyer@gmail.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-01-20kmemleak: Only scan non-zero-size areasTiejun Chen1-1/+1
Kmemleak should only track valid scan areas with a non-zero size. Otherwise, such area may reside just at the end of an object and kmemleak would report "Adding scan area to unknown object". Signed-off-by: Tiejun Chen <tiejun.chen@windriver.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2012-01-17Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds1-1/+1
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (47 commits) tg3: Fix single-vector MSI-X code openvswitch: Fix multipart datapath dumps. ipv6: fix per device IP snmp counters inetpeer: initialize ->redirect_genid in inet_getpeer() net: fix NULL-deref in WARN() in skb_gso_segment() net: WARN if skb_checksum_help() is called on skb requiring segmentation caif: Remove bad WARN_ON in caif_dev caif: Fix typo in Vendor/Product-ID for CAIF modems bnx2x: Disable AN KR work-around for BCM57810 bnx2x: Remove AutoGrEEEn for BCM84833 bnx2x: Remove 100Mb force speed for BCM84833 bnx2x: Fix PFC setting on BCM57840 bnx2x: Fix Super-Isolate mode for BCM84833 net: fix some sparse errors net: kill duplicate included header net: sh-eth: Fix build error by the value which is not defined net: Use device model to get driver name in skb_gso_segment() bridge: BH already disabled in br_fdb_cleanup() net: move sock_update_memcg outside of CONFIG_INET mwl8k: Fixing Sparse ENDIAN CHECK warning ...
2012-01-17net: move sock_update_memcg outside of CONFIG_INETGlauber Costa1-1/+1
Although only used currently for tcp sockets, this function is now used in common sock code (for sock_clone()) Commit 475f1b52645a29936b9df1d8fcd45f7e56bd4a9f moved the declaration of sock_update_clone() to inside sock.c, but this only fixes the problem when CONFIG_CGROUP_MEM_RES_CTLR_KMEM is also not defined. This patch here is verified to fix both problems, although reverting the previous one is not necessary. Signed-off-by: Glauber Costa <glommer@parallels.com> CC: David S. Miller <davem@davemloft.net> CC: Stephen Rothwell <sfr@canb.auug.org.au> Reported-by: Randy Dunlap <rdunlap@xenotime.net> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-16memblock: Fix alloc failure due to dumb underflow protection in ↵Tejun Heo1-2/+5
memblock_find_in_range_node() 7bd0b0f0da ("memblock: Reimplement memblock allocation using reverse free area iterator") implemented a simple top-down allocator using a reverse memblock iterator. To avoid underflow in the allocator loop, it simply raised the lower boundary to the requested size under the assumption that requested size would be far smaller than available memblocks. This causes early page table allocation failure under certain configurations in Xen. Fix it by checking for underflow directly instead of bumping up lower bound. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: rjw@sisk.pl Cc: xen-devel@lists.xensource.com Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20120113181412.GA11112@google.com Signed-off-by: Ingo Molnar <mingo@elte.hu>
2012-01-14Merge tag 'kmemleak' of ↵Linus Torvalds2-27/+143
git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux Kmemleak patches Main features: - Handle percpu memory allocations (only scanning them, not actually reporting). - Memory hotplug support. Usability improvements: - Show the origin of early allocations. - Report previously found leaks even if kmemleak has been disabled by some error. * tag 'kmemleak' of git://git.kernel.org/pub/scm/linux/kernel/git/cmarinas/linux: kmemleak: Add support for memory hotplug kmemleak: Handle percpu memory allocation kmemleak: Report previously found leaks even after an error kmemleak: When the early log buffer is exceeded, report the actual number kmemleak: Show where early_log issues come from
2012-01-12mm/vmalloc.c: eliminate extra loop in pcpu_get_vm_areas error pathKautuk Consul1-5/+4
If either of the vas or vms arrays are not properly kzalloced, then the code jumps to the err_free label. The err_free label runs a loop to check and free each of the array members of the vas and vms arrays which is not required for this situation as none of the array members have been allocated till this point. Eliminate the extra loop we have to go through by introducing a new label err_free2 and then jumping to it. [akpm@linux-foundation.org: remove now-unneeded tests] Signed-off-by: Kautuk Consul <consul.kautuk@gmail.com> 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>
2012-01-12mm: rearrange putback_inactive_pagesHugh Dickins1-52/+44
There is sometimes confusion between the global putback_lru_pages() in migrate.c and the static putback_lru_pages() in vmscan.c: rename the latter putback_inactive_pages(): it helps shrink_inactive_list() rather as move_active_pages_to_lru() helps shrink_active_list(). Remove unused scan_control arg from putback_inactive_pages() and from update_isolated_counts(). Move clear_active_flags() inside update_isolated_counts(). Move NR_ISOLATED accounting up into shrink_inactive_list() itself, so the balance is clearer. Do the spin_lock_irq() before calling putback_inactive_pages() and spin_unlock_irq() after return from it, so that it better matches update_isolated_counts() and move_active_pages_to_lru(). Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: remove isolate_pages()Hugh Dickins1-34/+27
The isolate_pages() level in vmscan.c offers little but indirection: merge it into isolate_lru_pages() as the compiler does, and use the names nr_to_scan and nr_scanned in each case. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: remove del_page_from_lru, add page_off_lruHugh Dickins1-2/+2
del_page_from_lru() repeats del_page_from_lru_list(), also working out which LRU the page was on, clearing the relevant bits. Decouple those functions: remove del_page_from_lru() and add page_off_lru(). Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: enum lru_list lruHugh Dickins2-14/+14
Mostly we use "enum lru_list lru": change those few "l"s to "lru"s. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: no blank line after EXPORT_SYMBOL in swap.cHugh Dickins1-5/+0
checkpatch rightly protests WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable so fix the five offenders in mm/swap.c. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: fewer underscores in ____pagevec_lru_addHugh Dickins1-6/+6
What's so special about ____pagevec_lru_add() that it needs four leading underscores? Nothing, it just helped to distinguish from __pagevec_lru_add() in 2.6.28 development. Cut two leading underscores. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: take pagevecs off reclaim stackHugh Dickins2-37/+40
Replace pagevecs in putback_lru_pages() and move_active_pages_to_lru() by lists of pages_to_free: then apply Konstantin Khlebnikov's free_hot_cold_page_list() to them instead of pagevec_release(). Which simplifies the flow (no need to drop and retake lock whenever pagevec fills up) and reduces stale addresses in stack backtraces (which often showed through the pagevecs); but more importantly, removes another 120 bytes from the deepest stacks in page reclaim. Although I've not recently seen an actual stack overflow here with a vanilla kernel, move_active_pages_to_lru() has often featured in deep backtraces. However, free_hot_cold_page_list() does not handle compound pages (nor need it: a Transparent HugePage would have been split by the time it reaches the call in shrink_page_list()), but it is possible for putback_lru_pages() or move_active_pages_to_lru() to be left holding the last reference on a THP, so must exclude the unlikely compound case before putting on pages_to_free. Remove pagevec_strip(), its work now done in move_active_pages_to_lru(). The pagevec in scan_mapping_unevictable_pages() remains in mm/vmscan.c, but that is never on the reclaim path, and cannot be replaced by a list. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.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>
2012-01-12memcg: fix mem_cgroup_print_bad_pageHugh Dickins1-16/+1
If DEBUG_VM, mem_cgroup_print_bad_page() is called whenever bad_page() shows a "Bad page state" message, removes page from circulation, adds a taint and continues. This is at a very low level, often when a spinlock is held (sometimes when page table lock is held, for example). We want to recover from this badness, not make it worse: we must not kmalloc memory here, we must not do a cgroup path lookup via dubious pointers. No doubt that code was useful to debug a particular case at one time, and may be again, but take it out of the mainline kernel. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12memcg: fix split_huge_page_refcounts()Hugh Dickins3-30/+21
This patch started off as a cleanup: __split_huge_page_refcounts() has to cope with two scenarios, when the hugepage being split is already on LRU, and when it is not; but why does it have to split that accounting across three different sites? Consolidate it in lru_add_page_tail(), handling evictable and unevictable alike, and use standard add_page_to_lru_list() when accounting is needed (when the head is not yet on LRU). But a recent regression in -next, I guess the removal of PageCgroupAcctLRU test from mem_cgroup_split_huge_fixup(), makes this now a necessary fix: under load, the MEM_CGROUP_ZSTAT count was wrapping to a huge number, messing up reclaim calculations and causing a freeze at rmdir of cgroup. Add a VM_BUG_ON to mem_cgroup_lru_del_list() when we're about to wrap that count - this has not been the only such incident. Document that lru_add_page_tail() is for Transparent HugePages by #ifdef around it. Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: vmscan: check if reclaim should really abort even if compaction_ready() ↵Mel Gorman1-10/+9
is true for one zone If compaction can proceed for a given zone, shrink_zones() does not reclaim any more pages from it. After commit [e0c2327: vmscan: abort reclaim/compaction if compaction can proceed], do_try_to_free_pages() tries to finish as soon as possible once one zone can compact. This was intended to prevent slabs being shrunk unnecessarily but there are side-effects. One is that a small zone that is ready for compaction will abort reclaim even if the chances of successfully allocating a THP from that zone is small. It also means that reclaim can return too early even though sc->nr_to_reclaim pages were not reclaimed. This partially reverts the commit until it is proven that slabs are really being shrunk unnecessarily but preserves the check to return 1 to avoid OOM if reclaim was aborted prematurely. [aarcange@redhat.com: This patch replaces a revert from Andrea] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: vmscan: when reclaiming for compaction, ensure there are sufficient free ↵Mel Gorman1-5/+39
pages available In commit e0887c19 ("vmscan: limit direct reclaim for higher order allocations"), Rik noted that reclaim was too aggressive when THP was enabled. In his initial patch he used the number of free pages to decide if reclaim should abort for compaction. My feedback was that reclaim and compaction should be using the same logic when deciding if reclaim should be aborted. Unfortunately, this had the effect of reducing THP success rates when the workload included something like streaming reads that continually allocated pages. The window during which compaction could run and return a THP was too small. This patch combines Rik's two patches together. compaction_suitable() is still used to decide if reclaim should be aborted to allow compaction is used. However, it will also ensure that there is a reasonable buffer of free pages available. This improves upon the THP allocation success rates but bounds the number of pages that are freed for compaction. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: compaction: introduce sync-light migration for use by compactionMel Gorman5-39/+47
This patch adds a lightweight sync migrate operation MIGRATE_SYNC_LIGHT mode that avoids writing back pages to backing storage. Async compaction maps to MIGRATE_ASYNC while sync compaction maps to MIGRATE_SYNC_LIGHT. For other migrate_pages users such as memory hotplug, MIGRATE_SYNC is used. This avoids sync compaction stalling for an excessive length of time, particularly when copying files to a USB stick where there might be a large number of dirty pages backed by a filesystem that does not support ->writepages. [aarcange@redhat.com: This patch is heavily based on Andrea's work] [akpm@linux-foundation.org: fix fs/nfs/write.c build] [akpm@linux-foundation.org: fix fs/btrfs/disk-io.c build] Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: page allocator: do not call direct reclaim for THP allocations while ↵Mel Gorman1-10/+35
compaction is deferred If compaction is deferred, direct reclaim is used to try to free enough pages for the allocation to succeed. For small high-orders, this has a reasonable chance of success. However, if the caller has specified __GFP_NO_KSWAPD to limit the disruption to the system, it makes more sense to fail the allocation rather than stall the caller in direct reclaim. This patch skips direct reclaim if compaction is deferred and the caller specifies __GFP_NO_KSWAPD. Async compaction only considers a subset of pages so it is possible for compaction to be deferred prematurely and not enter direct reclaim even in cases where it should. To compensate for this, this patch also defers compaction only if sync compaction failed. Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: compaction: make isolate_lru_page() filter-aware againMel Gorman2-2/+36
Commit 39deaf85 ("mm: compaction: make isolate_lru_page() filter-aware") noted that compaction does not migrate dirty or writeback pages and that is was meaningless to pick the page and re-add it to the LRU list. This had to be partially reverted because some dirty pages can be migrated by compaction without blocking. This patch updates "mm: compaction: make isolate_lru_page" by skipping over pages that migration has no possibility of migrating to minimise LRU disruption. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel<riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Minchan Kim <minchan@kernel.org> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: compaction: determine if dirty pages can be migrated without blocking ↵Mel Gorman1-37/+92
within ->migratepage Asynchronous compaction is used when allocating transparent hugepages to avoid blocking for long periods of time. Due to reports of stalling, there was a debate on disabling synchronous compaction but this severely impacted allocation success rates. Part of the reason was that many dirty pages are skipped in asynchronous compaction by the following check; if (PageDirty(page) && !sync && mapping->a_ops->migratepage != migrate_page) rc = -EBUSY; This skips over all mapping aops using buffer_migrate_page() even though it is possible to migrate some of these pages without blocking. This patch updates the ->migratepage callback with a "sync" parameter. It is the responsibility of the callback to fail gracefully if migration would block. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: vmscan: do not OOM if aborting reclaim to start compactionMel Gorman1-1/+7
During direct reclaim it is possible that reclaim will be aborted so that compaction can be attempted to satisfy a high-order allocation. If this decision is made before any pages are reclaimed, it is possible that 0 is returned to the page allocator potentially triggering an OOM. This has not been observed but it is a possibility so this patch addresses it. Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-01-12mm: vmscan: check if we isolated a compound page during lumpy scanAndrea Arcangeli1-3/+7
Properly take into account if we isolated a compound page during the lumpy scan in reclaim and skip over the tail pages when encountered. This corrects the values given to the tracepoint for number of lumpy pages isolated and will avoid breaking the loop early if compound pages smaller than the requested allocation size are requested. [mgorman@suse.de: Updated changelog] Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: Rik van Riel <riel@redhat.com> Cc: Dave Jones <davej@redhat.com> Cc: Jan Kara <jack@suse.cz> Cc: Andy Isaacson <adi@hexapodia.org> Cc: Nai Xia <nai.xia@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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