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2013-06-13mm: memcontrol: fix lockless reclaim hierarchy iteratorJohannes Weiner1-7/+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>
2013-06-13frontswap: fix incorrect zeroing and allocation size for frontswap_mapAkinobu Mita2-2/+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>
2013-06-13mm: migration: add migrate_entry_wait_huge()Naoya Horiguchi2-6/+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>
2013-06-13mm/page_alloc.c: fix watermark check in __zone_watermark_ok()Tomasz Stanislawski1-2/+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>
2013-06-13swap: avoid read_swap_cache_async() race to deadlock while waiting on ↵Rafael Aquini1-1/+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>
2013-06-13memcg: don't initialize kmem-cache destroying work for root cachesAndrey Vagin1-2/+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>
2013-06-06arch, mm: Remove tlb_fast_mode()Peter Zijlstra1-9/+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>
2013-05-25mm/pagewalk.c: walk_page_range should avoid VM_PFNMAP areasCliff Wickman1-34/+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>
2013-05-25mm/memory_hotplug.c: fix printk format warningsRandy Dunlap1-3/+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>
2013-05-25mm/THP: use pmd_populate() to update the pmd with pgtable_t pointerAneesh Kumar K.V1-1/+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>
2013-05-25mm compaction: fix of improper cache flush in migration codeLeonid Yegoshin1-1/+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>
2013-05-25mm: memcg: remove incorrect VM_BUG_ON for swap cache pages in unchargeJohannes Weiner1-2/+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>
2013-05-25mm: mmu_notifier: re-fix freed page still mapped in secondary MMUXiao Guangrong1-40/+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>
2013-05-22mm: Fix virt_to_page() warningRalf Baechle1-1/+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>
2013-05-10shm: fix null pointer deref when userspace specifies invalid hugepage sizeLi Zefan1-2/+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>
2013-05-09mm/slab: Fix crash during slab initChris Mason1-10/+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>
2013-05-08Merge branch 'for-3.10/core' of git://git.kernel.dk/linux-blockLinus Torvalds3-286/+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() ...
2013-05-08aio: don't include aio.h in sched.hKent Overstreet3-0/+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>
2013-05-08mm: remove old aio use_mm() commentZach Brown1-3/+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>
2013-05-08mm/vmalloc.c: add vfree commentAndrew Morton1-0/+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>
2013-05-08hugetlbfs: fix mmap failure in unaligned size requestNaoya Horiguchi1-1/+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>
2013-05-08mm, memcg: add rss_huge stat to memory.statDavid Rientjes1-10/+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>
2013-05-07Merge branch 'slab/for-linus' of ↵Linus Torvalds4-639/+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 ...
2013-05-07Merge branch 'slab/next' into slab/for-linusPekka Enberg4-639/+589
2013-05-07mm, slab_common: Fix bootstrap creation of kmalloc cachesChristoph Lameter1-9/+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>
2013-05-06slab: Return NULL for oversized allocationsChristoph Lameter1-0/+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>
2013-05-02Merge branch 'for-linus' of ↵Linus Torvalds3-10/+40
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull VFS updates from Al Viro, Misc cleanups all over the place, mainly wrt /proc interfaces (switch create_proc_entry to proc_create(), get rid of the deprecated create_proc_read_entry() in favor of using proc_create_data() and seq_file etc). 7kloc removed. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (204 commits) don't bother with deferred freeing of fdtables proc: Move non-public stuff from linux/proc_fs.h to fs/proc/internal.h proc: Make the PROC_I() and PDE() macros internal to procfs proc: Supply a function to remove a proc entry by PDE take cgroup_open() and cpuset_open() to fs/proc/base.c ppc: Clean up scanlog ppc: Clean up rtas_flash driver somewhat hostap: proc: Use remove_proc_subtree() drm: proc: Use remove_proc_subtree() drm: proc: Use minor->index to label things, not PDE->name drm: Constify drm_proc_list[] zoran: Don't print proc_dir_entry data in debug reiserfs: Don't access the proc_dir_entry in r_open(), r_start() r_show() proc: Supply an accessor for getting the data from a PDE's parent airo: Use remove_proc_subtree() rtl8192u: Don't need to save device proc dir PDE rtl8187se: Use a dir under /proc/net/r8180/ proc: Add proc_mkdir_data() proc: Move some bits from linux/proc_fs.h to linux/{of.h,signal.h,tty.h} proc: Move PDE_NET() to fs/proc/proc_net.c ...
2013-05-02Merge branch 'vfree' into for-nextAl Viro1-5/+40
2013-05-01Merge branch 'for-linus' of ↵Linus Torvalds3-26/+4
git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal Pull compat cleanup from Al Viro: "Mostly about syscall wrappers this time; there will be another pile with patches in the same general area from various people, but I'd rather push those after both that and vfs.git pile are in." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/signal: syscalls.h: slightly reduce the jungles of macros get rid of union semop in sys_semctl(2) arguments make do_mremap() static sparc: no need to sign-extend in sync_file_range() wrapper ppc compat wrappers for add_key(2) and request_key(2) are pointless x86: trim sys_ia32.h x86: sys32_kill and sys32_mprotect are pointless get rid of compat_sys_semctl() and friends in case of ARCH_WANT_OLD_COMPAT_IPC merge compat sys_ipc instances consolidate compat lookup_dcookie() convert vmsplice to COMPAT_SYSCALL_DEFINE switch getrusage() to COMPAT_SYSCALL_DEFINE switch epoll_pwait to COMPAT_SYSCALL_DEFINE convert sendfile{,64} to COMPAT_SYSCALL_DEFINE switch signalfd{,4}() to COMPAT_SYSCALL_DEFINE make SYSCALL_DEFINE<n>-generated wrappers do asmlinkage_protect make HAVE_SYSCALL_WRAPPERS unconditional consolidate cond_syscall and SYSCALL_ALIAS declarations teach SYSCALL_DEFINE<n> how to deal with long long/unsigned long long get rid of duplicate logics in __SC_....[1-6] definitions
2013-05-01mm: slab: Verify the nodeid passed to ____cache_alloc_nodeAaron Tomlin1-0/+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>
2013-05-01mm: cleancache: clean up cleancache_enabledBob Liu1-11/+0
cleancache_ops is used to decide whether backend is registered. So now cleancache_enabled is always true if defined CONFIG_CLEANCACHE. Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01cleancache: Make cleancache_init use a pointer for the opsKonrad Rzeszutek Wilk1-30/+32
Instead of using a backend_registered to determine whether a backend is enabled. This allows us to remove the backend_register check and just do 'if (cleancache_ops)' [v1: Rebase on top of b97c4b430b0a (ramster->zcache move] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01mm: cleancache: lazy initialization to allow tmem backends to build/run as ↵Dan Magenheimer1-21/+219
modules With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to be built/loaded as modules rather than built-in and enabled by a boot parameter, this patch provides "lazy initialization", allowing backends to register to cleancache even after filesystems were mounted. Calls to init_fs and init_shared_fs are remembered as fake poolids but no real tmem_pools created. On backend registration the fake poolids are mapped to real poolids and respective tmem_pools. Signed-off-by: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Florian Schmaus <fschmaus@gmail.com> Signed-off-by: Andor Daam <andor.daam@googlemail.com> Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v1: Minor fixes: used #define for some values and bools] [v2: Removed CLEANCACHE_HAS_LAZY_INIT] [v3: Added more comments, added a lock for [shared_|]fs_poolid_map] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01frontswap: get rid of swap_lock dependencyMinchan Kim2-16/+32
Frontswap initialization routine depends on swap_lock, which want to be atomic about frontswap's first appearance. IOW, frontswap is not present and will fail all calls OR frontswap is fully functional but if new swap_info_struct isn't registered by enable_swap_info, swap subsystem doesn't start I/O so there is no race between init procedure and page I/O working on frontswap. So let's remove unnecessary swap_lock dependency. Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Signed-off-by: Minchan Kim <minchan@kernel.org> [v1: Rebased on my branch, reworked to work with backends loading late] [v2: Added a check for !map] [v3: Made the invalidate path follow the init path] [v4: Address comments by Wanpeng Li <liwanp@linux.vnet.ibm.com>] Signed-off-by: Konrad Rzeszutek Wilk <konrad@darnok.org> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01mm: frontswap: cleanup codeBob Liu1-27/+30
After allowing tmem backends to build/run as modules, frontswap_enabled always true if defined CONFIG_FRONTSWAP. But frontswap_test() depends on whether backend is registered, mv it into frontswap.c using fronstswap_ops to make the decision. frontswap_set/clear are not used outside frontswap, so don't export them. Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01frontswap: make frontswap_init use a pointer for the opsKonrad Rzeszutek Wilk1-20/+18
This simplifies the code in the frontswap - we can get rid of the 'backend_registered' test and instead check against frontswap_ops. [v1: Rebase on top of 703ba7fe5e0 (ramster->zcache move] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Andor Daam <andor.daam@googlemail.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Florian Schmaus <fschmaus@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-05-01mm: frontswap: lazy initialization to allow tmem backends to build/run as ↵Dan Magenheimer1-10/+84
modules With the goal of allowing tmem backends (zcache, ramster, Xen tmem) to be built/loaded as modules rather than built-in and enabled by a boot parameter, this patch provides "lazy initialization", allowing backends to register to frontswap even after swapon was run. Before a backend registers all calls to init are recorded and the creation of tmem_pools delayed until a backend registers or until a frontswap store is attempted. Signed-off-by: Stefan Hengelein <ilendir@googlemail.com> Signed-off-by: Florian Schmaus <fschmaus@gmail.com> Signed-off-by: Andor Daam <andor.daam@googlemail.com> Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> [v1: Fixes per Seth Jennings suggestions] [v2: Removed FRONTSWAP_HAS_.. ] [v3: Fix up per Bob Liu <lliubbo@gmail.com> recommendations] [v4: Fix up per Andrew's comments] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Bob Liu <lliubbo@gmail.com> Cc: Wanpeng Li <liwanp@linux.vnet.ibm.com> Cc: Dan Magenheimer <dan.magenheimer@oracle.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30Merge branch 'for-linus' of ↵Linus Torvalds3-11/+9
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina: "Usual stuff, mostly comment fixes, typo fixes, printk fixes and small code cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (45 commits) mm: Convert print_symbol to %pSR gfs2: Convert print_symbol to %pSR m32r: Convert print_symbol to %pSR iostats.txt: add easy-to-find description for field 6 x86 cmpxchg.h: fix wrong comment treewide: Fix typo in printk and comments doc: devicetree: Fix various typos docbook: fix 8250 naming in device-drivers pata_pdc2027x: Fix compiler warning treewide: Fix typo in printks mei: Fix comments in drivers/misc/mei treewide: Fix typos in kernel messages pm44xx: Fix comment for "CONFIG_CPU_IDLE" doc: Fix typo "CONFIG_CGROUP_CGROUP_MEMCG_SWAP" mmzone: correct "pags" to "pages" in comment. kernel-parameters: remove outdated 'noresidual' parameter Remove spurious _H suffixes from ifdef comments sound: Remove stray pluses from Kconfig file radio-shark: Fix printk "CONFIG_LED_CLASS" doc: put proper reference to CONFIG_MODULE_SIG_ENFORCE ...
2013-04-30Merge branch 'akpm' (incoming from Andrew)Linus Torvalds1-1/+1
Merge second batch of fixes from Andrew Morton: - various misc bits - some printk updates - a new "SRAM" driver. - MAINTAINERS updates - the backlight driver queue - checkpatch updates - a few init/ changes - a huge number of drivers/rtc changes - fatfs updates - some lib/idr.c work - some renaming of the random driver interfaces * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (285 commits) net: rename random32 to prandom net/core: remove duplicate statements by do-while loop net/core: rename random32() to prandom_u32() net/netfilter: rename random32() to prandom_u32() net/sched: rename random32() to prandom_u32() net/sunrpc: rename random32() to prandom_u32() scsi: rename random32() to prandom_u32() lguest: rename random32() to prandom_u32() uwb: rename random32() to prandom_u32() video/uvesafb: rename random32() to prandom_u32() mmc: rename random32() to prandom_u32() drbd: rename random32() to prandom_u32() kernel/: rename random32() to prandom_u32() mm/: rename random32() to prandom_u32() lib/: rename random32() to prandom_u32() x86: rename random32() to prandom_u32() x86: pageattr-test: remove srandom32 call uuid: use prandom_bytes() raid6test: use prandom_bytes() sctp: convert sctp_assoc_set_id() to use idr_alloc_cyclic() ...
2013-04-30Merge branch 'for-3.10' of ↵Linus Torvalds1-31/+49
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: - Fixes and a lot of cleanups. Locking cleanup is finally complete. cgroup_mutex is no longer exposed to individual controlelrs which used to cause nasty deadlock issues. Li fixed and cleaned up quite a bit including long standing ones like racy cgroup_path(). - device cgroup now supports proper hierarchy thanks to Aristeu. - perf_event cgroup now supports proper hierarchy. - A new mount option "__DEVEL__sane_behavior" is added. As indicated by the name, this option is to be used for development only at this point and generates a warning message when used. Unfortunately, cgroup interface currently has too many brekages and inconsistencies to implement a consistent and unified hierarchy on top. The new flag is used to collect the behavior changes which are necessary to implement consistent unified hierarchy. It's likely that this flag won't be used verbatim when it becomes ready but will be enabled implicitly along with unified hierarchy. The option currently disables some of broken behaviors in cgroup core and also .use_hierarchy switch in memcg (will be routed through -mm), which can be used to make very unusual hierarchy where nesting is partially honored. It will also be used to implement hierarchy support for blk-throttle which would be impossible otherwise without introducing a full separate set of control knobs. This is essentially versioning of interface which isn't very nice but at this point I can't see any other options which would allow keeping the interface the same while moving towards hierarchy behavior which is at least somewhat sane. The planned unified hierarchy is likely to require some level of adaptation from userland anyway, so I think it'd be best to take the chance and update the interface such that it's supportable in the long term. Maintaining the existing interface does complicate cgroup core but shouldn't put too much strain on individual controllers and I think it'd be manageable for the foreseeable future. Maybe we'll be able to drop it in a decade. Fix up conflicts (including a semantic one adding a new #include to ppc that was uncovered by header the file changes) as per Tejun. * 'for-3.10' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (45 commits) cpuset: fix compile warning when CONFIG_SMP=n cpuset: fix cpu hotplug vs rebuild_sched_domains() race cpuset: use rebuild_sched_domains() in cpuset_hotplug_workfn() cgroup: restore the call to eventfd->poll() cgroup: fix use-after-free when umounting cgroupfs cgroup: fix broken file xattrs devcg: remove parent_cgroup. memcg: force use_hierarchy if sane_behavior cgroup: remove cgrp->top_cgroup cgroup: introduce sane_behavior mount option move cgroupfs_root to include/linux/cgroup.h cgroup: convert cgroupfs_root flag bits to masks and add CGRP_ prefix cgroup: make cgroup_path() not print double slashes Revert "cgroup: remove bind() method from cgroup_subsys." perf: make perf_event cgroup hierarchical cgroup: implement cgroup_is_descendant() cgroup: make sure parent won't be destroyed before its children cgroup: remove bind() method from cgroup_subsys. devcg: remove broken_hierarchy tag cgroup: remove cgroup_lock_is_held() ...
2013-04-30mm/: rename random32() to prandom_u32()Akinobu Mita1-1/+1
Use preferable function name which implies using a pseudo-random number generator. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30memcg: take reference before releasing rcu_read_lockLi Zefan1-30/+33
The memcg is not referenced, so it can be destroyed at anytime right after we exit rcu read section, so it's not safe to access it. To fix this, we call css_tryget() to get a reference while we're still in rcu read section. This also removes a bogus comment above __memcg_create_cache_enqueue(). Signed-off-by: Li Zefan <lizefan@huawei.com> Acked-by: Glauber Costa <glommer@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30mmKconfig: add an option to disable bounceVinayak Menon1-1/+7
There are times when HIGHMEM is enabled, but we don't prefer CONFIG_BOUNCE to be enabled. CONFIG_BOUNCE can reduce the block device throughput, and this is not ideal for machines where we don't gain much by enabling it. So provide an option to deselect CONFIG_BOUNCE. The observation was made while measuring eMMC throughput using iozone on an ARM device with 1GB RAM. Signed-off-by: Vinayak Menon <vinayakm.list@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Russell King <rmk@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30mm, nobootmem: do memset() after memblock_reserve()Joonsoo Kim1-1/+1
Currently, we do memset() before reserving the area. This may not cause any problem, but it is somewhat weird. So change execution order. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jiang Liu <liuj97@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30mm, nobootmem: clean-up of free_low_memory_core_early()Joonsoo Kim1-2/+2
Remove unused argument and make function static, because there is no user outside of nobootmem.c Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Yinghai Lu <yinghai@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jiang Liu <liuj97@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30mm: fix memory_hotplug.c printk format warningRandy Dunlap1-4/+8
PFN_PHYS() is a phys_addr_t, which can be u32 or u64. Fix the build warning when phys_addr_t is u32. mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 2 has type 'unsigned int' [-Wformat]: => 1685:3 mm/memory_hotplug.c: warning: format '%llx' expects argument of type 'long long unsigned int', but argument 3 has type 'unsigned int' [-Wformat]: => 1685:3 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>
2013-04-30mm: swap: mark swap pages writeback before queueing for direct IOMel Gorman1-0/+15
As pointed out by Andrew Morton, the swap-over-NFS writeback is not setting PageWriteback before it is queued for direct IO. While swap pages do not participate in BDI or process dirty accounting and the IO is synchronous, the writeback bit is still required and not setting it in this case was an oversight. swapoff depends on the page writeback to synchronoise all pending writes on a swap page before it is reused. Swapcache freeing and reuse depend on checking the PageWriteback under lock to ensure the page is safe to reuse. Direct IO handlers and the direct IO handler for NFS do not deal with PageWriteback as they are synchronous writes. In the case of NFS, it schedules pages (or a page in the case of swap) for IO and then waits synchronously for IO to complete in nfs_direct_write(). It is recognised that this is a slowdown from normal swap handling which is asynchronous and uses a completion handler. Shoving PageWriteback handling down into direct IO handlers looks like a bad fit to handle the swap case although it may have to be dealt with some day if swap is converted to use direct IO in general and bmap is finally done away with. At that point it will be necessary to refit asynchronous direct IO with completion handlers onto the swap subsystem. As swapcache currently depends on PageWriteback to protect against races, this patch sets PageWriteback under the page lock before queueing it for direct IO. It is cleared when the direct IO handler returns. IO errors are treated similarly to the direct-to-bio case except PageError is not set as in the case of swap-over-NFS, it is likely to be a transient error. It was asked what prevents such a page being reclaimed in parallel. With this patch applied, such a page will now be skipped (most of the time) or blocked until the writeback completes. Reclaim checks PageWriteback under the page lock before calling try_to_free_swap and the page lock should prevent the page being requeued for IO before it is freed. This and Jerome's related patch should considered for -stable as far back as 3.6 when swap-over-NFS was introduced. [akpm@linux-foundation.org: use pr_err_ratelimited()] [akpm@linux-foundation.org: remove hopefully-unneeded cast in printk] Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [3.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30swap: redirty page if page write fails on swap fileJerome Marchand1-0/+2
Since commit 62c230bc1790 ("mm: add support for a filesystem to activate swap files and use direct_IO for writing swap pages"), swap_writepage() calls direct_IO on swap files. However, in that case the page isn't redirtied if I/O fails, and is therefore handled afterwards as if it has been successfully written to the swap file, leading to memory corruption when the page is eventually swapped back in. This patch sets the page dirty when direct_IO() fails. It fixes a memory corruption that happened while using swap-over-NFS. Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [3.6+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30mm, memcg: give exiting processes access to memory reservesDavid Rientjes1-4/+4
A memcg may livelock when oom if the process that grabs the hierarchy's oom lock is never the first process with PF_EXITING set in the memcg's task iteration. The oom killer, both global and memcg, will defer if it finds an eligible process that is in the process of exiting and it is not being ptraced. The idea is to allow it to exit without using memory reserves before needlessly killing another process. This normally works fine except in the memcg case with a large number of threads attached to the oom memcg. In this case, the memcg oom killer only gets called for the process that grabs the hierarchy's oom lock; all others end up blocked on the memcg's oom waitqueue. Thus, if the process that grabs the hierarchy's oom lock is never the first PF_EXITING process in the memcg's task iteration, the oom killer is constantly deferred without anything making progress. The fix is to give PF_EXITING processes access to memory reserves so that we've marked them as oom killed without any iteration. This allows __mem_cgroup_try_charge() to succeed so that the process may exit. This makes the memcg oom killer exemption for TIF_MEMDIE tasks, now immediately granted for processes with pending SIGKILLs and those in the exit path, to be equivalent to what is done for the global oom killer. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-04-30thp: fix huge zero page logic for page with pfn == 0Kirill A. Shutemov1-23/+22
Current implementation of huge zero page uses pfn value 0 to indicate that the page hasn't allocated yet. It assumes that buddy page allocator can't return page with pfn == 0. Let's rework the code to store 'struct page *' of huge zero page, not its pfn. This way we can avoid the weak assumption. [akpm@linux-foundation.org: fix sparse warning] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Minchan Kim <minchan@kernel.org> Acked-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>