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* Merge branch 'sched-mm-for-linus' of ↵Linus Torvalds2013-07-021-3/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull voluntary preemption fixes from Ingo Molnar: "This tree contains a speedup which is achieved through better might_sleep()/might_fault() preemption point annotations for uaccess functions, by Michael S Tsirkin: 1. The only reason uaccess routines might sleep is if they fault. Make this explicit for all architectures. 2. A voluntary preemption point in uaccess functions means compiler can't inline them efficiently, this breaks assumptions that they are very fast and small that e.g. net code seems to make. Remove this preemption point so behaviour matches with what callers assume. 3. Accesses (e.g through socket ops) to kernel memory with KERNEL_DS like net/sunrpc does will never sleep. Remove an unconditinal might_sleep() in the might_fault() inline in kernel.h (used when PROVE_LOCKING is not set). 4. Accesses with pagefault_disable() return EFAULT but won't cause caller to sleep. Check for that and thus avoid might_sleep() when PROVE_LOCKING is set. These changes offer a nice speedup for CONFIG_PREEMPT_VOLUNTARY=y kernels, here's a network bandwidth measurement between a virtual machine and the host: before: incoming: 7122.77 Mb/s outgoing: 8480.37 Mb/s after: incoming: 8619.24 Mb/s [ +21.0% ] outgoing: 9455.42 Mb/s [ +11.5% ] I kept these changes in a separate tree, separate from scheduler changes, because it's a mixed MM and scheduler topic" * 'sched-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: mm, sched: Allow uaccess in atomic with pagefault_disable() mm, sched: Drop voluntary schedule from might_fault() x86: uaccess s/might_sleep/might_fault/ tile: uaccess s/might_sleep/might_fault/ powerpc: uaccess s/might_sleep/might_fault/ mn10300: uaccess s/might_sleep/might_fault/ microblaze: uaccess s/might_sleep/might_fault/ m32r: uaccess s/might_sleep/might_fault/ frv: uaccess s/might_sleep/might_fault/ arm64: uaccess s/might_sleep/might_fault/ asm-generic: uaccess s/might_sleep/might_fault/
| * mm, sched: Allow uaccess in atomic with pagefault_disable()Michael S. Tsirkin2013-05-281-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This changes might_fault() so that it does not trigger a false positive diagnostic for e.g. the following sequence: spin_lock_irqsave() pagefault_disable() copy_to_user() pagefault_enable() spin_unlock_irqrestore() In particular vhost wants to do this, to call socket ops from under a lock. There are 3 cases to consider: - CONFIG_PROVE_LOCKING - might_fault is non-inline so it's easy to move the in_atomic test to fix up the false positive warning. - CONFIG_DEBUG_ATOMIC_SLEEP - might_fault is currently inline, but we are calling a non-inline __might_sleep anyway, so let's use the non-line version of might_fault that does the right thing. - !CONFIG_DEBUG_ATOMIC_SLEEP && !CONFIG_PROVE_LOCKING __might_sleep is a nop so might_fault is a nop. Make this explicit. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1369577426-26721-11-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * mm, sched: Drop voluntary schedule from might_fault()Michael S. Tsirkin2013-05-281-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | might_fault() is called from functions like copy_to_user() which most callers expect to be very fast, like a couple of instructions. So functions like memcpy_toiovec() call them many times in a loop. But might_fault() calls might_sleep() and with CONFIG_PREEMPT_VOLUNTARY this results in a function call. Let's not do this - just call __might_sleep() that produces a diagnostic for sleep within atomic, but drop might_preempt(). Here's a test sending traffic between the VM and the host, host is built with CONFIG_PREEMPT_VOLUNTARY: before: incoming: 7122.77 Mb/s outgoing: 8480.37 Mb/s after: incoming: 8619.24 Mb/s outgoing: 9455.42 Mb/s As a side effect, this fixes an issue pointed out by Ingo: might_fault might schedule differently depending on PROVE_LOCKING. Now there's no preemption point in both cases, so it's consistent. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1369577426-26721-10-git-send-email-mst@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | Merge branch 'core-locking-for-linus' of ↵Linus Torvalds2013-07-021-0/+17
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking changes from Ingo Molnar: "Four miscellanous standalone fixes for futexes, rtmutexes and Kconfig.locks." * 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Use freezable blocking call futex: Take hugepages into account when generating futex_key rtmutex: Document rt_mutex_adjust_prio_chain() locking: Fix copy/paste errors of "ARCH_INLINE_*_UNLOCK_BH"
| * | futex: Take hugepages into account when generating futex_keyZhang Yi2013-06-251-0/+17
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The futex_keys of process shared futexes are generated from the page offset, the mapping host and the mapping index of the futex user space address. This should result in an unique identifier for each futex. Though this is not true when futexes are located in different subpages of an hugepage. The reason is, that the mapping index for all those futexes evaluates to the index of the base page of the hugetlbfs mapping. So a futex at offset 0 of the hugepage mapping and another one at offset PAGE_SIZE of the same hugepage mapping have identical futex_keys. This happens because the futex code blindly uses page->index. Steps to reproduce the bug: 1. Map a file from hugetlbfs. Initialize pthread_mutex1 at offset 0 and pthread_mutex2 at offset PAGE_SIZE of the hugetlbfs mapping. The mutexes must be initialized as PTHREAD_PROCESS_SHARED because PTHREAD_PROCESS_PRIVATE mutexes are not affected by this issue as their keys solely depend on the user space address. 2. Lock mutex1 and mutex2 3. Create thread1 and in the thread function lock mutex1, which results in thread1 blocking on the locked mutex1. 4. Create thread2 and in the thread function lock mutex2, which results in thread2 blocking on the locked mutex2. 5. Unlock mutex2. Despite the fact that mutex2 got unlocked, thread2 still blocks on mutex2 because the futex_key points to mutex1. To solve this issue we need to take the normal page index of the page which contains the futex into account, if the futex is in an hugetlbfs mapping. In other words, we calculate the normal page mapping index of the subpage in the hugetlbfs mapping. Mappings which are not based on hugetlbfs are not affected and still use page->index. Thanks to Mel Gorman who provided a patch for adding proper evaluation functions to the hugetlbfs code to avoid exposing hugetlbfs specific details to the futex code. [ tglx: Massaged changelog ] Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn> Tested-by: Ma Chenggong <ma.chenggong@zte.com.cn> Reviewed-by: 'Mel Gorman' <mgorman@suse.de> Acked-by: 'Darren Hart' <dvhart@linux.intel.com> Cc: 'Peter Zijlstra' <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/000101ce71a6%24a83c5880%24f8b50980%24@com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | Merge tag 'driver-core-3.11-rc1' of ↵Linus Torvalds2013-07-021-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the big driver core merge for 3.11-rc1 Lots of little things, and larger firmware subsystem updates, all described in the shortlog. Nice thing here is that we finally get rid of CONFIG_HOTPLUG, after 10+ years, thanks to Stephen Rohtwell (it had been always on for a number of kernel releases, now it's just removed)" * tag 'driver-core-3.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (27 commits) driver core: device.h: fix doc compilation warnings firmware loader: fix another compile warning with PM_SLEEP unset build some drivers only when compile-testing firmware loader: fix compile warning with PM_SLEEP set kobject: sanitize argument for format string sysfs_notify is only possible on file attributes firmware loader: simplify holding module for request_firmware firmware loader: don't export cache_firmware and uncache_firmware drivers/base: Use attribute groups to create sysfs memory files firmware loader: fix compile warning firmware loader: fix build failure with !CONFIG_FW_LOADER_USER_HELPER Documentation: Updated broken link in HOWTO Finally eradicate CONFIG_HOTPLUG driver core: firmware loader: kill FW_ACTION_NOHOTPLUG requests before suspend driver core: firmware loader: don't cache FW_ACTION_NOHOTPLUG firmware Documentation: Tidy up some drivers/base/core.c kerneldoc content. platform_device: use a macro instead of platform_driver_register firmware: move EXPORT_SYMBOL annotations firmware: Avoid deadlock of usermodehelper lock at shutdown dell_rbu: Select CONFIG_FW_LOADER_USER_HELPER explicitly ...
| * \ Merge 3.10-rc7 into driver-core-nextGreg Kroah-Hartman2013-06-241-1/+3
| |\ \ | | | | | | | | | | | | | | | | | | | | We want the firmware merge fixes, and other bits, in here now. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * \ \ Merge 3.10-rc6 into driver-core-nextGreg Kroah-Hartman2013-06-178-29/+47
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | We want these fixes here too. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * | | | Finally eradicate CONFIG_HOTPLUGStephen Rothwell2013-06-031-1/+1
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ever since commit 45f035ab9b8f ("CONFIG_HOTPLUG should be always on"), it has been basically impossible to build a kernel with CONFIG_HOTPLUG turned off. Remove all the remaining references to it. Cc: Russell King <linux@arm.linux.org.uk> Cc: Doug Thompson <dougthompson@xmission.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Pavel Machek <pavel@ucw.cz> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com> Acked-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | | | Merge tag 'ext4_for_linus' of ↵Linus Torvalds2013-07-022-37/+82
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 update from Ted Ts'o: "Lots of bug fixes, cleanups and optimizations. In the bug fixes category, of note is a fix for on-line resizing file systems where the block size is smaller than the page size (i.e., file systems 1k blocks on x86, or more interestingly file systems with 4k blocks on Power or ia64 systems.) In the cleanup category, the ext4's punch hole implementation was significantly improved by Lukas Czerner, and now supports bigalloc file systems. In addition, Jan Kara significantly cleaned up the write submission code path. We also improved error checking and added a few sanity checks. In the optimizations category, two major optimizations deserve mention. The first is that ext4_writepages() is now used for nodelalloc and ext3 compatibility mode. This allows writes to be submitted much more efficiently as a single bio request, instead of being sent as individual 4k writes into the block layer (which then relied on the elevator code to coalesce the requests in the block queue). Secondly, the extent cache shrink mechanism, which was introduce in 3.9, no longer has a scalability bottleneck caused by the i_es_lru spinlock. Other optimizations include some changes to reduce CPU usage and to avoid issuing empty commits unnecessarily." * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (86 commits) ext4: optimize starting extent in ext4_ext_rm_leaf() jbd2: invalidate handle if jbd2_journal_restart() fails ext4: translate flag bits to strings in tracepoints ext4: fix up error handling for mpage_map_and_submit_extent() jbd2: fix theoretical race in jbd2__journal_restart ext4: only zero partial blocks in ext4_zero_partial_blocks() ext4: check error return from ext4_write_inline_data_end() ext4: delete unnecessary C statements ext3,ext4: don't mess with dir_file->f_pos in htree_dirblock_to_tree() jbd2: move superblock checksum calculation to jbd2_write_superblock() ext4: pass inode pointer instead of file pointer to punch hole ext4: improve free space calculation for inline_data ext4: reduce object size when !CONFIG_PRINTK ext4: improve extent cache shrink mechanism to avoid to burn CPU time ext4: implement error handling of ext4_mb_new_preallocation() ext4: fix corruption when online resizing a fs with 1K block size ext4: delete unused variables ext4: return FIEMAP_EXTENT_UNKNOWN for delalloc extents jbd2: remove debug dependency on debug_fs and update Kconfig help text jbd2: use a single printk for jbd_debug() ...
| * | | mm: teach truncate_inode_pages_range() to handle non page aligned rangesLukas Czerner2013-05-271-31/+73
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit changes truncate_inode_pages_range() so it can handle non page aligned regions of the truncate. Currently we can hit BUG_ON when the end of the range is not page aligned, but we can handle unaligned start of the range. Being able to handle non page aligned regions of the page can help file system punch_hole implementations and save some work, because once we're holding the page we might as well deal with it right away. In previous commits we've changed ->invalidatepage() prototype to accept 'length' argument to be able to specify range to invalidate. No we can use that new ability in truncate_inode_pages_range(). Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
| * | | mm: change invalidatepage prototype to accept lengthLukas Czerner2013-05-212-7/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently there is no way to truncate partial page where the end truncate point is not at the end of the page. This is because it was not needed and the functionality was enough for file system truncate operation to work properly. However more file systems now support punch hole feature and it can benefit from mm supporting truncating page just up to the certain point. Specifically, with this functionality truncate_inode_pages_range() can be changed so it supports truncating partial page at the end of the range (currently it will BUG_ON() if 'end' is not at the end of the page). This commit changes the invalidatepage() address space operation prototype to accept range to be invalidated and update all the instances for it. We also change the block_invalidatepage() in the same way and actually make a use of the new length argument implementing range invalidation. Actual file system implementations will follow except the file systems where the changes are really simple and should not change the behaviour in any way .Implementation for truncate_page_range() which will be able to accept page unaligned ranges will follow as well. Signed-off-by: Lukas Czerner <lczerner@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Hugh Dickins <hughd@google.com>
* | | | Merge branch 'slab/urgent' of ↵Linus Torvalds2013-06-181-1/+3
|\ \ \ \ | |_|_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull SLAB fix from Pekka Enberg: "A slab regression fix by Sasha Levin" * 'slab/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: slab: prevent warnings when allocating with __GFP_NOWARN
| * | | slab: prevent warnings when allocating with __GFP_NOWARNSasha Levin2013-06-131-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sasha Levin noticed that the warning introduced by commit 6286ae9 ("slab: Return NULL for oversized allocations) is being triggered: WARNING: CPU: 15 PID: 21519 at mm/slab_common.c:376 kmalloc_slab+0x2f/0xb0() can: request_module (can-proto-4) failed. mpoa: proc_mpc_write: could not parse '' Modules linked in: CPU: 15 PID: 21519 Comm: trinity-child15 Tainted: G W 3.10.0-rc4-next-20130607-sasha-00011-gcd78395-dirty #2 0000000000000009 ffff880020a95e30 ffffffff83ff4041 0000000000000000 ffff880020a95e68 ffffffff8111fe12 fffffffffffffff0 00000000000082d0 0000000000080000 0000000000080000 0000000001400000 ffff880020a95e78 Call Trace: [<ffffffff83ff4041>] dump_stack+0x4e/0x82 [<ffffffff8111fe12>] warn_slowpath_common+0x82/0xb0 [<ffffffff8111fe55>] warn_slowpath_null+0x15/0x20 [<ffffffff81243dcf>] kmalloc_slab+0x2f/0xb0 [<ffffffff81278d54>] __kmalloc+0x24/0x4b0 [<ffffffff8196ffe3>] ? security_capable+0x13/0x20 [<ffffffff812a26b7>] ? pipe_fcntl+0x107/0x210 [<ffffffff812a26b7>] pipe_fcntl+0x107/0x210 [<ffffffff812b7ea0>] ? fget_raw_light+0x130/0x3f0 [<ffffffff812aa5fb>] SyS_fcntl+0x60b/0x6a0 [<ffffffff8403ca98>] tracesys+0xe1/0xe6 Andrew Morton writes: __GFP_NOWARN is frequently used by kernel code to probe for "how big an allocation can I get". That's a bit lame, but it's used on slow paths and is pretty simple. However, SLAB would still spew a warning when a big allocation happens if the __GFP_NOWARN flag is _not_ set to expose kernel bugs. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> [ penberg@kernel.org: improve changelog ] Signed-off-by: Pekka Enberg <penberg@kernel.org>
* | | | mm: memcontrol: fix lockless reclaim hierarchy iteratorJohannes Weiner2013-06-121-7/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The lockless reclaim hierarchy iterator currently has a misplaced barrier that can lead to use-after-free crashes. The reclaim hierarchy iterator consist of a sequence count and a position pointer that are read and written locklessly, with memory barriers enforcing ordering. The write side sets the position pointer first, then updates the sequence count to "publish" the new position. Likewise, the read side must read the sequence count first, then the position. If the sequence count is up to date, it's guaranteed that the position is up to date as well: writer: reader: iter->position = position if iter->sequence == expected: smp_wmb() smp_rmb() iter->sequence = sequence position = iter->position However, the read side barrier is currently misplaced, which can lead to dereferencing stale position pointers that no longer point to valid memory. Fix this. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: Tejun Heo <tj@kernel.org> Reviewed-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Glauber Costa <glommer@parallels.com> Cc: <stable@kernel.org> [3.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | frontswap: fix incorrect zeroing and allocation size for frontswap_mapAkinobu Mita2013-06-122-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The bitmap accessed by bitops must have enough size to hold the required numbers of bits rounded up to a multiple of BITS_PER_LONG. And the bitmap must not be zeroed by memset() if the number of bits cleared is not a multiple of BITS_PER_LONG. This fixes incorrect zeroing and allocation size for frontswap_map. The incorrect zeroing part doesn't cause any problem because frontswap_map is freed just after zeroing. But the wrongly calculated allocation size may cause the problem. For 32bit systems, the allocation size of frontswap_map is about twice as large as required size. For 64bit systems, the allocation size is smaller than requeired if the number of bits is not a multiple of BITS_PER_LONG. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm: migration: add migrate_entry_wait_huge()Naoya Horiguchi2013-06-122-6/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When we have a page fault for the address which is backed by a hugepage under migration, the kernel can't wait correctly and do busy looping on hugepage fault until the migration finishes. As a result, users who try to kick hugepage migration (via soft offlining, for example) occasionally experience long delay or soft lockup. This is because pte_offset_map_lock() can't get a correct migration entry or a correct page table lock for hugepage. This patch introduces migration_entry_wait_huge() to solve this. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Rik van Riel <riel@redhat.com> Reviewed-by: Wanpeng Li <liwanp@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@vger.kernel.org> [2.6.35+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | mm/page_alloc.c: fix watermark check in __zone_watermark_ok()Tomasz Stanislawski2013-06-121-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The watermark check consists of two sub-checks. The first one is: if (free_pages <= min + lowmem_reserve) return false; The check assures that there is minimal amount of RAM in the zone. If CMA is used then the free_pages is reduced by the number of free pages in CMA prior to the over-mentioned check. if (!(alloc_flags & ALLOC_CMA)) free_pages -= zone_page_state(z, NR_FREE_CMA_PAGES); This prevents the zone from being drained from pages available for non-movable allocations. The second check prevents the zone from getting too fragmented. for (o = 0; o < order; o++) { free_pages -= z->free_area[o].nr_free << o; min >>= 1; if (free_pages <= min) return false; } The field z->free_area[o].nr_free is equal to the number of free pages including free CMA pages. Therefore the CMA pages are subtracted twice. This may cause a false positive fail of __zone_watermark_ok() if the CMA area gets strongly fragmented. In such a case there are many 0-order free pages located in CMA. Those pages are subtracted twice therefore they will quickly drain free_pages during the check against fragmentation. The test fails even though there are many free non-cma pages in the zone. This patch fixes this issue by subtracting CMA pages only for a purpose of (free_pages <= min + lowmem_reserve) check. Laura said: We were observing allocation failures of higher order pages (order 5 = 128K typically) under tight memory conditions resulting in driver failure. The output from the page allocation failure showed plenty of free pages of the appropriate order/type/zone and mostly CMA pages in the lower orders. For full disclosure, we still observed some page allocation failures even after applying the patch but the number was drastically reduced and those failures were attributed to fragmentation/other system issues. Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com> Tested-by: Laura Abbott <lauraa@codeaurora.org> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mel@csn.ul.ie> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Cc: <stable@vger.kernel.org> [3.7+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | swap: avoid read_swap_cache_async() race to deadlock while waiting on ↵Rafael Aquini2013-06-121-1/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | discard I/O completion read_swap_cache_async() can race against get_swap_page(), and stumble across a SWAP_HAS_CACHE entry in the swap map whose page wasn't brought into the swapcache yet. This transient swap_map state is expected to be transitory, but the actual placement of discard at scan_swap_map() inserts a wait for I/O completion thus making the thread at read_swap_cache_async() to loop around its -EEXIST case, while the other end at get_swap_page() is scheduled away at scan_swap_map(). This can leave the system deadlocked if the I/O completion happens to be waiting on the CPU waitqueue where read_swap_cache_async() is busy looping and !CONFIG_PREEMPT. This patch introduces a cond_resched() call to make the aforementioned read_swap_cache_async() busy loop condition to bail out when necessary, thus avoiding the subtle race window. Signed-off-by: Rafael Aquini <aquini@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Shaohua Li <shli@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | memcg: don't initialize kmem-cache destroying work for root cachesAndrey Vagin2013-06-121-2/+0
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct memcg_cache_params has a union. Different parts of this union are used for root and non-root caches. A part with destroying work is used only for non-root caches. BUG: unable to handle kernel paging request at 0000000fffffffe0 IP: kmem_cache_alloc+0x41/0x1f0 Modules linked in: netlink_diag af_packet_diag udp_diag tcp_diag inet_diag unix_diag ip6table_filter ip6_tables i2c_piix4 virtio_net virtio_balloon microcode i2c_core pcspkr floppy CPU: 0 PID: 1929 Comm: lt-vzctl Tainted: G D 3.10.0-rc1+ #2 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 RIP: kmem_cache_alloc+0x41/0x1f0 Call Trace: getname_flags.part.34+0x30/0x140 getname+0x38/0x60 do_sys_open+0xc5/0x1e0 SyS_open+0x22/0x30 system_call_fastpath+0x16/0x1b Code: f4 53 48 83 ec 18 8b 05 8e 53 b7 00 4c 8b 4d 08 21 f0 a8 10 74 0d 4c 89 4d c0 e8 1b 76 4a 00 4c 8b 4d c0 e9 92 00 00 00 4d 89 f5 <4d> 8b 45 00 65 4c 03 04 25 48 cd 00 00 49 8b 50 08 4d 8b 38 49 RIP [<ffffffff8116b641>] kmem_cache_alloc+0x41/0x1f0 Signed-off-by: Andrey Vagin <avagin@openvz.org> Cc: Konstantin Khlebnikov <khlebnikov@openvz.org> Cc: Glauber Costa <glommer@parallels.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Balbir Singh <bsingharora@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: Li Zefan <lizefan@huawei.com> Cc: <stable@vger.kernel.org> [3.9.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | arch, mm: Remove tlb_fast_mode()Peter Zijlstra2013-06-061-9/+0
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since the introduction of preemptible mmu_gather TLB fast mode has been broken. TLB fast mode relies on there being absolutely no concurrency; it frees pages first and invalidates TLBs later. However now we can get concurrency and stuff goes *bang*. This patch removes all tlb_fast_mode() code; it was found the better option vs trying to patch the hole by entangling tlb invalidation with the scheduler. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Reported-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areasCliff Wickman2013-05-241-34/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A panic can be caused by simply cat'ing /proc/<pid>/smaps while an application has a VM_PFNMAP range. It happened in-house when a benchmarker was trying to decipher the memory layout of his program. /proc/<pid>/smaps and similar walks through a user page table should not be looking at VM_PFNMAP areas. Certain tests in walk_page_range() (specifically split_huge_page_pmd()) assume that all the mapped PFN's are backed with page structures. And this is not usually true for VM_PFNMAP areas. This can result in panics on kernel page faults when attempting to address those page structures. There are a half dozen callers of walk_page_range() that walk through a task's entire page table (as N. Horiguchi pointed out). So rather than change all of them, this patch changes just walk_page_range() to ignore VM_PFNMAP areas. The logic of hugetlb_vma() is moved back into walk_page_range(), as we want to test any vma in the range. VM_PFNMAP areas are used by: - graphics memory manager gpu/drm/drm_gem.c - global reference unit sgi-gru/grufile.c - sgi special memory char/mspec.c - and probably several out-of-tree modules [akpm@linux-foundation.org: remove now-unused hugetlb_vma() stub] Signed-off-by: Cliff Wickman <cpw@sgi.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: David Sterba <dsterba@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: KOSAKI Motohiro <kosaki.motohiro@gmail.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/memory_hotplug.c: fix printk format warningsRandy Dunlap2013-05-241-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | Fix printk format warnings in mm/memory_hotplug.c by using "%pa": mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'resource_size_t' [-Wformat] mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'resource_size_t' [-Wformat] Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm/THP: use pmd_populate() to update the pmd with pgtable_t pointerAneesh Kumar K.V2013-05-241-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We should not use set_pmd_at to update pmd_t with pgtable_t pointer. set_pmd_at is used to set pmd with huge pte entries and architectures like ppc64, clear few flags from the pte when saving a new entry. Without this change we observe bad pte errors like below on ppc64 with THP enabled. BUG: Bad page map in process ld mm=0xc000001ee39f4780 pte:7fc3f37848000001 pmd:c000001ec0000000 Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Reviewed-by: 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>
* | mm compaction: fix of improper cache flush in migration codeLeonid Yegoshin2013-05-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Page 'new' during MIGRATION can't be flushed with flush_cache_page(). Using flush_cache_page(vma, addr, pfn) is justified only if the page is already placed in process page table, and that is done right after flush_cache_page(). But without it the arch function has no knowledge of process PTE and does nothing. Besides that, flush_cache_page() flushes an application cache page, but the kernel has a different page virtual address and dirtied it. Replace it with flush_dcache_page(new) which is the proper usage. The old page is flushed in try_to_unmap_one() before migration. This bug takes place in Sead3 board with M14Kc MIPS CPU without cache aliasing (but Harvard arch - separate I and D cache) in tight memory environment (128MB) each 1-3days on SOAK test. It fails in cc1 during kernel build (SIGILL, SIGBUS, SIGSEG) if CONFIG_COMPACTION is switched ON. Signed-off-by: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Leonid Yegoshin <yegoshin@mips.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Michal Hocko <mhocko@suse.cz> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Miller <davem@davemloft.net> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: memcg: remove incorrect VM_BUG_ON for swap cache pages in unchargeJohannes Weiner2013-05-241-2/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 0c59b89c81ea ("mm: memcg: push down PageSwapCache check into uncharge entry functions") added a VM_BUG_ON() on PageSwapCache in the uncharge path after checking that page flag once, assuming that the state is stable in all paths, but this is not the case and the condition triggers in user environments. An uncharge after the last page table reference to the page goes away can race with reclaim adding the page to swap cache. Swap cache pages are usually uncharged when they are freed after swapout, from a path that also handles swap usage accounting and memcg lifetime management. However, since the last page table reference is gone and thus no references to the swap slot left, the swap slot will be freed shortly when reclaim attempts to write the page to disk. The whole swap accounting is not even necessary. So while the race condition for which this VM_BUG_ON was added is real and actually existed all along, there are no negative effects. Remove the VM_BUG_ON again. Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com> Reported-by: Lingzhu Xiang <lxiang@redhat.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Hugh Dickins <hughd@google.com> Acked-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>
* | mm: mmu_notifier: re-fix freed page still mapped in secondary MMUXiao Guangrong2013-05-241-40/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 751efd8610d3 ("mmu_notifier_unregister NULL Pointer deref and multiple ->release()") breaks the fix 3ad3d901bbcf ("mm: mmu_notifier: fix freed page still mapped in secondary MMU"). Since hlist_for_each_entry_rcu() is changed now, we can not revert that patch directly, so this patch reverts the commit and simply fix the bug spotted by that patch This bug spotted by commit 751efd8610d3 is: There is a race condition between mmu_notifier_unregister() and __mmu_notifier_release(). Assume two tasks, one calling mmu_notifier_unregister() as a result of a filp_close() ->flush() callout (task A), and the other calling mmu_notifier_release() from an mmput() (task B). A B t1 srcu_read_lock() t2 if (!hlist_unhashed()) t3 srcu_read_unlock() t4 srcu_read_lock() t5 hlist_del_init_rcu() t6 synchronize_srcu() t7 srcu_read_unlock() t8 hlist_del_rcu() <--- NULL pointer deref. This can be fixed by using hlist_del_init_rcu instead of hlist_del_rcu. The another issue spotted in the commit is "multiple ->release() callouts", we needn't care it too much because it is really rare (e.g, can not happen on kvm since mmu-notify is unregistered after exit_mmap()) and the later call of multiple ->release should be fast since all the pages have already been released by the first call. Anyway, this issue should be fixed in a separate patch. -stable suggestions: Any version that has commit 751efd8610d3 need to be backported. I find the oldest version has this commit is 3.0-stable. [akpm@linux-foundation.org: tweak comments] Signed-off-by: Xiao Guangrong <xiaoguangrong@linux.vnet.ibm.com> Tested-by: Robin Holt <holt@sgi.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | mm: Fix virt_to_page() warningRalf Baechle2013-05-221-1/+1
|/ | | | | | | | | | | | | | | | | | | | | | | virt_to_page() is typically implemented as a macro containing a cast so that it will accept both pointers and unsigned long without causing a warning. But MIPS virt_to_page() uses virt_to_phys which is a function so passing an unsigned long will cause a warning: CC mm/page_alloc.o mm/page_alloc.c: In function ‘free_reserved_area’: mm/page_alloc.c:5161:3: warning: passing argument 1 of ‘virt_to_phys’ makes pointer from integer without a cast [enabled by default] arch/mips/include/asm/io.h:119:100: note: expected ‘const volatile void *’ but argument is of type ‘long unsigned int’ All others users of virt_to_page() in mm/ are passing a void *. Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Reported-by: Eunbong Song <eunb.song@samsung.com> Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* shm: fix null pointer deref when userspace specifies invalid hugepage sizeLi Zefan2013-05-091-2/+6
| | | | | | | | | | | | | | | | | | | | | | | | | Dave reported an oops triggered by trinity: BUG: unable to handle kernel NULL pointer dereference at 0000000000000008 IP: newseg+0x10d/0x390 PGD cf8c1067 PUD cf8c2067 PMD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC CPU: 2 PID: 7636 Comm: trinity-child2 Not tainted 3.9.0+#67 ... Call Trace: ipcget+0x182/0x380 SyS_shmget+0x5a/0x60 tracesys+0xdd/0xe2 This bug was introduced by commit af73e4d9506d ("hugetlbfs: fix mmap failure in unaligned size request"). Reported-by: Dave Jones <davej@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Li Zefan <lizfan@huawei.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Rik van Riel <riel@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* mm/slab: Fix crash during slab initChris Mason2013-05-081-10/+10
| | | | | | | | | | | | | | | | | | | | | | Commit 8a965b3baa89 ("mm, slab_common: Fix bootstrap creation of kmalloc caches") introduced a regression that caused us to crash early during boot. The commit was introducing ordering of slab creation, making sure two odd-sized slabs were created after specific powers of two sizes. But, if any of the power of two slabs were created earlier during boot, slabs at index 1 or 2 might not get created at all. This patch makes sure none of the slabs get skipped. Tony Lindgren bisected this down to the offending commit, which really helped because bisect kept bringing me to almost but not quite this one. Signed-off-by: Chris Mason <chris.mason@fusionio.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Tony Lindgren <tony@atomide.com> Acked-by: Soren Brinkmann <soren.brinkmann@xilinx.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Tested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-blockLinus Torvalds2013-05-083-286/+49
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull block core updates from Jens Axboe: - Major bit is Kents prep work for immutable bio vecs. - Stable candidate fix for a scheduling-while-atomic in the queue bypass operation. - Fix for the hang on exceeded rq->datalen 32-bit unsigned when merging discard bios. - Tejuns changes to convert the writeback thread pool to the generic workqueue mechanism. - Runtime PM framework, SCSI patches exists on top of these in James' tree. - A few random fixes. * 'for-3.10/core' of git://git.kernel.dk/linux-block: (40 commits) relay: move remove_buf_file inside relay_close_buf partitions/efi.c: replace useless kzalloc's by kmalloc's fs/block_dev.c: fix iov_shorten() criteria in blkdev_aio_read() block: fix max discard sectors limit blkcg: fix "scheduling while atomic" in blk_queue_bypass_start Documentation: cfq-iosched: update documentation help for cfq tunables writeback: expose the bdi_wq workqueue writeback: replace custom worker pool implementation with unbound workqueue writeback: remove unused bdi_pending_list aoe: Fix unitialized var usage bio-integrity: Add explicit field for owner of bip_buf block: Add an explicit bio flag for bios that own their bvec block: Add bio_alloc_pages() block: Convert some code to bio_for_each_segment_all() block: Add bio_for_each_segment_all() bounce: Refactor __blk_queue_bounce to not use bi_io_vec raid1: use bio_copy_data() pktcdvd: Use bio_reset() in disabled code to kill bi_idx usage pktcdvd: use bio_copy_data() block: Add bio_copy_data() ...
| * Merge branch 'writeback-workqueue' of ↵Jens Axboe2013-04-026-250/+50
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq into for-3.10/core Tejun writes: ----- This is the pull request for the earlier patchset[1] with the same name. It's only three patches (the first one was committed to workqueue tree) but the merge strategy is a bit involved due to the dependencies. * Because the conversion needs features from wq/for-3.10, block/for-3.10/core is based on rc3, and wq/for-3.10 has conflicts with rc3, I pulled mainline (rc5) into wq/for-3.10 to prevent those workqueue conflicts from flaring up in block tree. * Resolving the issue that Jan and Dave raised about debugging requires arch-wide changes. The patchset is being worked on[2] but it'll have to go through -mm after these changes show up in -next, and not included in this pull request. The three commits are located in the following git branch. git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git writeback-workqueue Pulling it into block/for-3.10/core produces a conflict in drivers/md/raid5.c between the following two commits. e3620a3ad5 ("MD RAID5: Avoid accessing gendisk or queue structs when not available") 2f6db2a707 ("raid5: use bio_reset()") The conflict is trivial - one removes an "if ()" conditional while the other removes "rbi->bi_next = NULL" right above it. We just need to remove both. The merged branch is available at git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq.git block-test-merge so that you can use it for verification. The test merge commit has proper merge description. While these changes are a bit of pain to route, they make code simpler and even have, while minute, measureable performance gain[3] even on a workload which isn't particularly favorable to showing the benefits of this conversion. ---- Fixed up the conflict. Conflicts: drivers/md/raid5.c Signed-off-by: Jens Axboe <axboe@kernel.dk>
| | * writeback: expose the bdi_wq workqueueTejun Heo2013-04-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are cases where userland wants to tweak the priority and affinity of writeback flushers. Expose bdi_wq to userland by setting WQ_SYSFS. It appears under /sys/bus/workqueue/devices/writeback/ and allows adjusting maximum concurrency level, cpumask and nice level. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| | * writeback: replace custom worker pool implementation with unbound workqueueTejun Heo2013-04-011-227/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Writeback implements its own worker pool - each bdi can be associated with a worker thread which is created and destroyed dynamically. The worker thread for the default bdi is always present and serves as the "forker" thread which forks off worker threads for other bdis. there's no reason for writeback to implement its own worker pool when using unbound workqueue instead is much simpler and more efficient. This patch replaces custom worker pool implementation in writeback with an unbound workqueue. The conversion isn't too complicated but the followings are worth mentioning. * bdi_writeback->last_active, task and wakeup_timer are removed. delayed_work ->dwork is added instead. Explicit timer handling is no longer necessary. Everything works by either queueing / modding / flushing / canceling the delayed_work item. * bdi_writeback_thread() becomes bdi_writeback_workfn() which runs off bdi_writeback->dwork. On each execution, it processes bdi->work_list and reschedules itself if there are more things to do. The function also handles low-mem condition, which used to be handled by the forker thread. If the function is running off a rescuer thread, it only writes out limited number of pages so that the rescuer can serve other bdis too. This preserves the flusher creation failure behavior of the forker thread. * INIT_LIST_HEAD(&bdi->bdi_list) is used to tell bdi_writeback_workfn() about on-going bdi unregistration so that it always drains work_list even if it's running off the rescuer. Note that the original code was broken in this regard. Under memory pressure, a bdi could finish unregistration with non-empty work_list. * The default bdi is no longer special. It now is treated the same as any other bdi and bdi_cap_flush_forker() is removed. * BDI_pending is no longer used. Removed. * Some tracepoints become non-applicable. The following TPs are removed - writeback_nothread, writeback_wake_thread, writeback_wake_forker_thread, writeback_thread_start, writeback_thread_stop. Everything, including devices coming and going away and rescuer operation under simulated memory pressure, seems to work fine in my test setup. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Jeff Moyer <jmoyer@redhat.com>
| | * writeback: remove unused bdi_pending_listTejun Heo2013-04-011-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | There's no user left. Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Fengguang Wu <fengguang.wu@intel.com>
| * | block: Convert some code to bio_for_each_segment_all()Kent Overstreet2013-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | More prep work for immutable bvecs: A few places in the code were either open coding or using the wrong version - fix. After we introduce the bvec iter, it'll no longer be possible to modify the biovec through bio_for_each_segment_all() - it doesn't increment a pointer to the current bvec, you pass in a struct bio_vec (not a pointer) which is updated with what the current biovec would be (taking into account bi_bvec_done and bi_size). So because of that it's more worthwhile to be consistent about bio_for_each_segment()/bio_for_each_segment_all() usage. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: NeilBrown <neilb@suse.de> CC: Alasdair Kergon <agk@redhat.com> CC: dm-devel@redhat.com CC: Alexander Viro <viro@zeniv.linux.org.uk>
| * | block: Add bio_for_each_segment_all()Kent Overstreet2013-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __bio_for_each_segment() iterates bvecs from the specified index instead of bio->bv_idx. Currently, the only usage is to walk all the bvecs after the bio has been advanced by specifying 0 index. For immutable bvecs, we need to split these apart; bio_for_each_segment() is going to have a different implementation. This will also help document the intent of code that's using it - bio_for_each_segment_all() is only legal to use for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk> CC: Neil Brown <neilb@suse.de> CC: Boaz Harrosh <bharrosh@panasas.com>
| * | bounce: Refactor __blk_queue_bounce to not use bi_io_vecKent Overstreet2013-03-231-54/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A bunch of what __blk_queue_bounce() was doing was problematic for the immutable bvec work; this cleans that up and the code is quite a bit smaller, too. The __bio_for_each_segment() in copy_to_high_bio_irq() was changed because that one's looping over the original bio, not the bounce bio - a later patch renames __bio_for_each_segment() -> bio_for_each_segment_all(), and documents that bio_for_each_segment_all() is only for code that owns the bio. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
| * | block: Remove bi_idx referencesKent Overstreet2013-03-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For immutable bvecs, all bi_idx usage needs to be audited - so here we're removing all the unnecessary uses. Most of these are places where it was being initialized on a bio that was just allocated, a few others are conversions to standard macros. Signed-off-by: Kent Overstreet <koverstreet@google.com> CC: Jens Axboe <axboe@kernel.dk>
* | | aio: don't include aio.h in sched.hKent Overstreet2013-05-073-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Faster kernel compiles by way of fewer unnecessary includes. [akpm@linux-foundation.org: fix fallout] [akpm@linux-foundation.org: fix build] Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Zach Brown <zab@redhat.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm: remove old aio use_mm() commentZach Brown2013-05-071-3/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Bunch of performance improvements and cleanups Zach Brown and I have been working on. The code should be pretty solid at this point, though it could of course use more review and testing. The results in my testing are pretty impressive, particularly when an ioctx is being shared between multiple threads. In my crappy synthetic benchmark, with 4 threads submitting and one thread reaping completions, I saw overhead in the aio code go from ~50% (mostly ioctx lock contention) to low single digits. Performance with ioctx per thread improved too, but I'd have to rerun those benchmarks. The reason I've been focused on performance when the ioctx is shared is that for a fair number of real world completions, userspace needs the completions aggregated somehow - in practice people just end up implementing this aggregation in userspace today, but if it's done right we can do it much more efficiently in the kernel. Performance wise, the end result of this patch series is that submitting a kiocb writes to _no_ shared cachelines - the penalty for sharing an ioctx is gone there. There's still going to be some cacheline contention when we deliver the completions to the aio ringbuffer (at least if you have interrupts being delivered on multiple cores, which for high end stuff you do) but I have a couple more patches not in this series that implement coalescing for that (by taking advantage of interrupt coalescing). With that, there's basically no bottlenecks or performance issues to speak of in the aio code. This patch: use_mm() is used in more places than just aio. There's no need to mention callers when describing the function. Signed-off-by: Zach Brown <zab@redhat.com> Signed-off-by: Kent Overstreet <koverstreet@google.com> Cc: Felipe Balbi <balbi@ti.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jens Axboe <axboe@kernel.dk> Cc: Asai Thambi S P <asamymuthupa@micron.com> Cc: Selvan Mani <smani@micron.com> Cc: Sam Bradshaw <sbradshaw@micron.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Benjamin LaHaise <bcrl@kvack.org> Reviewed-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | mm/vmalloc.c: add vfree commentAndrew Morton2013-05-071-0/+2
| | | | | | | | | | | | | | | | | | Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | hugetlbfs: fix mmap failure in unaligned size requestNaoya Horiguchi2013-05-071-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current kernel returns -EINVAL unless a given mmap length is "almost" hugepage aligned. This is because in sys_mmap_pgoff() the given length is passed to vm_mmap_pgoff() as it is without being aligned with hugepage boundary. This is a regression introduced in commit 40716e29243d ("hugetlbfs: fix alignment of huge page requests"), where alignment code is pushed into hugetlb_file_setup() and the variable len in caller side is not changed. To fix this, this patch partially reverts that commit, and adds alignment code in caller side. And it also introduces hstate_sizelog() in order to get proper hstate to specified hugepage size. Addresses https://bugzilla.kernel.org/show_bug.cgi?id=56881 [akpm@linux-foundation.org: fix warning when CONFIG_HUGETLB_PAGE=n] Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Reported-by: <iceman_dvd@yahoo.com> Cc: Steven Truelove <steven.truelove@utoronto.ca> Cc: Jianguo Wu <wujianguo@huawei.com> 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>
* | | mm, memcg: add rss_huge stat to memory.statDavid Rientjes2013-05-071-10/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This exports the amount of anonymous transparent hugepages for each memcg via the new "rss_huge" stat in memory.stat. The units are in bytes. This is helpful to determine the hugepage utilization for individual jobs on the system in comparison to rss and opportunities where MADV_HUGEPAGE may be helpful. The amount of anonymous transparent hugepages is also included in "rss" for backwards compatibility. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> 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>
* | | Merge branch 'slab/for-linus' of ↵Linus Torvalds2013-05-074-639/+589
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux Pull slab changes from Pekka Enberg: "The bulk of the changes are more slab unification from Christoph. There's also few fixes from Aaron, Glauber, and Joonsoo thrown into the mix." * 'slab/for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux: (24 commits) mm, slab_common: Fix bootstrap creation of kmalloc caches slab: Return NULL for oversized allocations mm: slab: Verify the nodeid passed to ____cache_alloc_node slub: tid must be retrieved from the percpu area of the current processor slub: Do not dereference NULL pointer in node_match slub: add 'likely' macro to inc_slabs_node() slub: correct to calculate num of acquired objects in get_partial_node() slub: correctly bootstrap boot caches mm/sl[au]b: correct allocation type check in kmalloc_slab() slab: Fixup CONFIG_PAGE_ALLOC/DEBUG_SLAB_LEAK sections slab: Handle ARCH_DMA_MINALIGN correctly slab: Common definition for kmem_cache_node slab: Rename list3/l3 to node slab: Common Kmalloc cache determination stat: Use size_t for sizes instead of unsigned slab: Common function to create the kmalloc array slab: Common definition for the array of kmalloc caches slab: Common constants for kmalloc boundaries slab: Rename nodelists to node slab: Common name for the per node structures ...
| * \ \ Merge branch 'slab/next' into slab/for-linusPekka Enberg2013-05-074-639/+589
| |\ \ \
| | * | | mm, slab_common: Fix bootstrap creation of kmalloc cachesChristoph Lameter2013-05-061-9/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For SLAB the kmalloc caches must be created in ascending sizes in order for the OFF_SLAB sub-slab cache to work properly. Create the non power of two caches immediately after the prior power of two kmalloc cache. Do not create the non power of two caches before all other caches. Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Christoph Lamete <cl@linux.com> Link: http://lkml.kernel.org/r/201305040348.CIF81716.OStQOHFJMFLOVF@I-love.SAKURA.ne.jp Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slab: Return NULL for oversized allocationsChristoph Lameter2013-05-061-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The inline path seems to have changed the SLAB behavior for very large kmalloc allocations with commit e3366016 ("slab: Use common kmalloc_index/kmalloc_size functions"). This patch restores the old behavior but also adds diagnostics so that we can figure where in the code these large allocations occur. Reported-and-tested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Christoph Lameter <cl@linux.com> Link: http://lkml.kernel.org/r/201305040348.CIF81716.OStQOHFJMFLOVF@I-love.SAKURA.ne.jp [ penberg@kernel.org: use WARN_ON_ONCE ] Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | mm: slab: Verify the nodeid passed to ____cache_alloc_nodeAaron Tomlin2013-05-011-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the nodeid is > num_online_nodes() this can cause an Oops and a panic(). The purpose of this patch is to assert if this condition is true to aid debugging efforts rather than some random NULL pointer dereference or page fault. This patch is in response to BZ#42967 [1]. Using VM_BUG_ON so it's used only when CONFIG_DEBUG_VM is set, given that ____cache_alloc_node() is a hot code path. [1]: https://bugzilla.kernel.org/show_bug.cgi?id=42967 Signed-off-by: Aaron Tomlin <atomlin@redhat.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Christoph Lameter <cl@linux.com> Acked-by: Rafael Aquini <aquini@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
| | * | | slub: tid must be retrieved from the percpu area of the current processorChristoph Lameter2013-04-051-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As Steven Rostedt has pointer out: rescheduling could occur on a different processor after the determination of the per cpu pointer and before the tid is retrieved. This could result in allocation from the wrong node in slab_alloc(). The effect is much more severe in slab_free() where we could free to the freelist of the wrong page. The window for something like that occurring is pretty small but it is possible. Signed-off-by: Christoph Lameter <cl@linux.com> Signed-off-by: Pekka Enberg <penberg@kernel.org>
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