- 25 Jun, 2016 36 commits
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Michal Hocko authored
Tetsuo has reported the following potential oom_killer_disable vs. oom_reaper race: (1) freeze_processes() starts freezing user space threads. (2) Somebody (maybe a kenrel thread) calls out_of_memory(). (3) The OOM killer calls mark_oom_victim() on a user space thread P1 which is already in __refrigerator(). (4) oom_killer_disable() sets oom_killer_disabled = true. (5) P1 leaves __refrigerator() and enters do_exit(). (6) The OOM reaper calls exit_oom_victim(P1) before P1 can call exit_oom_victim(P1). (7) oom_killer_disable() returns while P1 not yet finished (8) P1 perform IO/interfere with the freezer. This situation is unfortunate. We cannot move oom_killer_disable after all the freezable kernel threads are frozen because the oom victim might depend on some of those kthreads to make a forward progress to exit so we could deadlock. It is also far from trivial to teach the oom_reaper to not call exit_oom_victim() because then we would lose a guarantee of the OOM killer and oom_killer_disable forward progress because exit_mm->mmput might block and never call exit_oom_victim. It seems the easiest way forward is to workaround this race by calling try_to_freeze_tasks again after oom_killer_disable. This will make sure that all the tasks are frozen or it bails out. Fixes: 449d777d ("mm, oom_reaper: clear TIF_MEMDIE for all tasks queued for oom_reaper") Link: http://lkml.kernel.org/r/1466597634-16199-1-git-send-email-mhocko@kernel.orgSigned-off-by:Michal Hocko <mhocko@suse.com> Reported-by:
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Gang He authored
According to some high-load testing, these two BUG assertions were encountered, this led system panic. Actually, there were some discussions about removing these two BUG() assertions, it would not bring any side effect. Then, I did the the following changes, 1) use the existing macro CATCH_BH_JBD_RACES to wrap BUG() in the ocfs2_read_blocks_sync function like before. 2) disable the macro CATCH_BH_JBD_RACES in Makefile by default. Link: http://lkml.kernel.org/r/1466574294-26863-1-git-send-email-ghe@suse.comSigned-off-by:
Gang He <ghe@suse.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by:
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David Rientjes authored
If the memory compaction free scanner cannot successfully split a free page (only possible due to per-zone low watermark), terminate the free scanner rather than continuing to scan memory needlessly. If the watermark is insufficient for a free page of order <= cc->order, then terminate the scanner since all future splits will also likely fail. This prevents the compaction freeing scanner from scanning all memory on very large zones (very noticeable for zones > 128GB, for instance) when all splits will likely fail while holding zone->lock. compaction_alloc() iterating a 128GB zone has been benchmarked to take over 400ms on some systems whereas any free page isolated and ready to be split ends up failing in split_free_page() because of the low watermark check and thus the iteration continues. The next time compaction occurs, the freeing scanner will likely start at the end of the zone again since no success was made previously and we get the same lengthy iteration until the zone is brought above the low watermark. All thp page faults can take >400ms in such a state without this fix. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1606211820350.97086@chino.kir.corp.google.comSigned-off-by:
David Rientjes <rientjes@google.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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Dmitry Vyukov authored
When kmemleak dumps contents of leaked objects it reads whole objects regardless of user-requested size. This upsets KASAN. Disable KASAN checks around object dump. Link: http://lkml.kernel.org/r/1466617631-68387-1-git-send-email-dvyukov@google.comSigned-off-by:
Dmitry Vyukov <dvyukov@google.com> Acked-by:
Catalin Marinas <catalin.marinas@arm.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by:
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Gerald Schaefer authored
While working on s390 support for gigantic hugepages I ran into the following "Bad page state" warning when freeing gigantic pages: BUG: Bad page state in process bash pfn:580001 page:000003d116000040 count:0 mapcount:0 mapping:ffffffff00000000 index:0x0 flags: 0x7fffc0000000000() page dumped because: non-NULL mapping This is because page->compound_mapcount, which is part of a union with page->mapping, is initialized with -1 in prep_compound_gigantic_page(), and not cleared again during destroy_compound_gigantic_page(). Fix this by clearing the compound_mapcount in destroy_compound_gigantic_page() before clearing compound_head. Interestingly enough, the warning will not show up on x86_64, although this should not be architecture specific. Apparently there is an endianness issue, combined with the fact that the union contains both a 64 bit ->mapping pointer and a 32 bit atomic_t ->compound_mapcount as members. The resulting bogus page->mapping on x86_64 therefore contains 00000000ffffffff instead of ffffffff00000000 on s390, which will falsely trigger the PageAnon() check in free_pages_prepare() because page->mapping & PAGE_MAPPING_ANON is true on little-endian architectures like x86_64 in this case (the page is not compound anymore, ->compound_head was already cleared before). As a result, page->mapping will be cleared before doing the checks in free_pages_check(). Not sure if the bogus "PageAnon() returning true" on x86_64 for the first tail page of a gigantic page (at this stage) has other theoretical implications, but they would also be fixed with this patch. Link: http://lkml.kernel.org/r/1466612719-5642-1-git-send-email-gerald.schaefer@de.ibm.comSigned-off-by:
Gerald Schaefer <gerald.schaefer@de.ibm.com> Reviewed-by:
Mike Kravetz <mike.kravetz@oracle.com> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: "Aneesh Kumar K . V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by:
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Lukasz Odzioba authored
Currently we can have compound pages held on per cpu pagevecs, which leads to a lot of memory unavailable for reclaim when needed. In the systems with hundreads of processors it can be GBs of memory. On of the way of reproducing the problem is to not call munmap explicitly on all mapped regions (i.e. after receiving SIGTERM). After that some pages (with THP enabled also huge pages) may end up on lru_add_pvec, example below. void main() { #pragma omp parallel { size_t size = 55 * 1000 * 1000; // smaller than MEM/CPUS void *p = mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS , -1, 0); if (p != MAP_FAILED) memset(p, 0, size); //munmap(p, size); // uncomment to make the problem go away } } When we run it with THP enabled it will leave significant amount of memory on lru_add_pvec. This memory will be not reclaimed if we hit OOM, so when we run above program in a loop: for i in `seq 100`; do ./a.out; done many processes (95% in my case) will be killed by OOM. The primary point of the LRU add cache is to save the zone lru_lock contention with a hope that more pages will belong to the same zone and so their addition can be batched. The huge page is already a form of batched addition (it will add 512 worth of memory in one go) so skipping the batching seems like a safer option when compared to a potential excess in the caching which can be quite large and much harder to fix because lru_add_drain_all is way to expensive and it is not really clear what would be a good moment to call it. Similarly we can reproduce the problem on lru_deactivate_pvec by adding: madvise(p, size, MADV_FREE); after memset. This patch flushes lru pvecs on compound page arrival making the problem less severe - after applying it kill rate of above example drops to 0%, due to reducing maximum amount of memory held on pvec from 28MB (with THP) to 56kB per CPU. Suggested-by:Lukasz Odzioba <lukasz.odzioba@intel.com> Acked-by:
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Tejun Heo authored
mem_cgroup_css_alloc() was returning NULL on failure while cgroup core expected it to return an ERR_PTR value leading to the following NULL deref after a css allocation failure. Fix it by return ERR_PTR(-ENOMEM) instead. I'll also update cgroup core so that it can handle NULL returns. mkdir: page allocation failure: order:6, mode:0x240c0c0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO) CPU: 0 PID: 8738 Comm: mkdir Not tainted 4.7.0-rc3+ #123 ... Call Trace: dump_stack+0x68/0xa1 warn_alloc_failed+0xd6/0x130 __alloc_pages_nodemask+0x4c6/0xf20 alloc_pages_current+0x66/0xe0 alloc_kmem_pages+0x14/0x80 kmalloc_order_trace+0x2a/0x1a0 __kmalloc+0x291/0x310 memcg_update_all_caches+0x6c/0x130 mem_cgroup_css_alloc+0x590/0x610 cgroup_apply_control_enable+0x18b/0x370 cgroup_mkdir+0x1de/0x2e0 kernfs_iop_mkdir+0x55/0x80 vfs_mkdir+0xb9/0x150 SyS_mkdir+0x66/0xd0 do_syscall_64+0x53/0x120 entry_SYSCALL64_slow_path+0x25/0x25 ... BUG: unable to handle kernel NULL pointer dereference at 00000000000000d0 IP: init_and_link_css+0x37/0x220 PGD 34b1e067 PUD 3a109067 PMD 0 Oops: 0002 [#1] SMP Modules linked in: CPU: 0 PID: 8738 Comm: mkdir Not tainted 4.7.0-rc3+ #123 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.2-20160422_131301-anatol 04/01/2014 task: ffff88007cbc5200 ti: ffff8800666d4000 task.ti: ffff8800666d4000 RIP: 0010:[<ffffffff810f2ca7>] [<ffffffff810f2ca7>] init_and_link_css+0x37/0x220 RSP: 0018:ffff8800666d7d90 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffffff810f2499 RSI: 0000000000000000 RDI: 0000000000000008 RBP: ffff8800666d7db8 R08: 0000000000000003 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff88005a5fb400 R13: ffffffff81f0f8a0 R14: ffff88005a5fb400 R15: 0000000000000010 FS: 00007fc944689700(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3aed0d2b80 CR3: 000000003a1e8000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: cgroup_apply_control_enable+0x1ac/0x370 cgroup_mkdir+0x1de/0x2e0 kernfs_iop_mkdir+0x55/0x80 vfs_mkdir+0xb9/0x150 SyS_mkdir+0x66/0xd0 do_syscall_64+0x53/0x120 entry_SYSCALL64_slow_path+0x25/0x25 Code: 89 f5 48 89 fb 49 89 d4 48 83 ec 08 8b 05 72 3b d8 00 85 c0 0f 85 60 01 00 00 4c 89 e7 e8 72 f7 ff ff 48 8d 7b 08 48 89 d9 31 c0 <48> c7 83 d0 00 00 00 00 00 00 00 48 83 e7 f8 48 29 f9 81 c1 d8 RIP init_and_link_css+0x37/0x220 RSP <ffff8800666d7d90> CR2: 00000000000000d0 ---[ end trace a2d8836ae1e852d1 ]--- Link: http://lkml.kernel.org/r/20160621165740.GJ3262@mtj.duckdns.orgSigned-off-by:Tejun Heo <tj@kernel.org> Reported-by:
Johannes Weiner <hannes@cmpxchg.org> Reviewed-by:
Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by:
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Tejun Heo authored
mem_cgroup_migrate() uses local_irq_disable/enable() but can be called with irq disabled from migrate_page_copy(). This ends up enabling irq while holding a irq context lock triggering the following lockdep warning. Fix it by using irq_save/restore instead. ================================= [ INFO: inconsistent lock state ] 4.7.0-rc1+ #52 Tainted: G W --------------------------------- inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage. kcompactd0/151 [HC0[0]:SC0[0]:HE1:SE1] takes: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: [<000000000038fd96>] aio_migratepage+0x156/0x1e8 {IN-SOFTIRQ-W} state was registered at: __lock_acquire+0x5b6/0x1930 lock_acquire+0xee/0x270 _raw_spin_lock_irqsave+0x66/0xb0 aio_complete+0x98/0x328 dio_complete+0xe4/0x1e0 blk_update_request+0xd4/0x450 scsi_end_request+0x48/0x1c8 scsi_io_completion+0x272/0x698 blk_done_softirq+0xca/0xe8 __do_softirq+0xc8/0x518 irq_exit+0xee/0x110 do_IRQ+0x6a/0x88 io_int_handler+0x11a/0x25c __mutex_unlock_slowpath+0x144/0x1d8 __mutex_unlock_slowpath+0x140/0x1d8 kernfs_iop_permission+0x64/0x80 __inode_permission+0x9e/0xf0 link_path_walk+0x6e/0x510 path_lookupat+0xc4/0x1a8 filename_lookup+0x9c/0x160 user_path_at_empty+0x5c/0x70 SyS_readlinkat+0x68/0x140 system_call+0xd6/0x270 irq event stamp: 971410 hardirqs last enabled at (971409): migrate_page_move_mapping+0x3ea/0x588 hardirqs last disabled at (971410): _raw_spin_lock_irqsave+0x3c/0xb0 softirqs last enabled at (970526): __do_softirq+0x460/0x518 softirqs last disabled at (970519): irq_exit+0xee/0x110 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&ctx->completion_lock)->rlock); <Interrupt> lock(&(&ctx->completion_lock)->rlock); *** DEADLOCK *** 3 locks held by kcompactd0/151: #0: (&(&mapping->private_lock)->rlock){+.+.-.}, at: aio_migratepage+0x42/0x1e8 #1: (&ctx->ring_lock){+.+.+.}, at: aio_migratepage+0x5a/0x1e8 #2: (&(&ctx->completion_lock)->rlock){+.?.-.}, at: aio_migratepage+0x156/0x1e8 stack backtrace: CPU: 20 PID: 151 Comm: kcompactd0 Tainted: G W 4.7.0-rc1+ #52 Call Trace: show_trace+0xea/0xf0 show_stack+0x72/0xf0 dump_stack+0x9a/0xd8 print_usage_bug.part.27+0x2d4/0x2e8 mark_lock+0x17e/0x758 mark_held_locks+0xa2/0xd0 trace_hardirqs_on_caller+0x140/0x1c0 mem_cgroup_migrate+0x266/0x370 aio_migratepage+0x16a/0x1e8 move_to_new_page+0xb0/0x260 migrate_pages+0x8f4/0x9f0 compact_zone+0x4dc/0xdc8 kcompactd_do_work+0x1aa/0x358 kcompactd+0xba/0x2c8 kthread+0x10a/0x110 kernel_thread_starter+0x6/0xc kernel_thread_starter+0x0/0xc INFO: lockdep is turned off. Link: http://lkml.kernel.org/r/20160620184158.GO3262@mtj.duckdns.org Link: http://lkml.kernel.org/g/5767CFE5.7080904@de.ibm.com Fixes: 74485cf2 ("mm: migrate: consolidate mem_cgroup_migrate() calls") Signed-off-by:Christian Borntraeger <borntraeger@de.ibm.com> Acked-by:
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Kirill A. Shutemov authored
We account HugeTLB's shared page table to all processes who share it. The accounting happens during huge_pmd_share(). If somebody populates pud entry under us, we should decrease pagetable's refcount and decrease nr_pmds of the process. By mistake, I increase nr_pmds again in this case. :-/ It will lead to "BUG: non-zero nr_pmds on freeing mm: 2" on process' exit. Let's fix this by increasing nr_pmds only when we're sure that the page table will be used. Link: http://lkml.kernel.org/r/20160617122506.GC6534@node.shutemov.name Fixes: dc6c9a35 ("mm: account pmd page tables to the process") Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by:
zhongjiang <zhongjiang@huawei.com> Reviewed-by:
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Kirill A. Shutemov authored
This reverts commit d0834a6c. After revert of 5c0a85fa ("mm: make faultaround produce old ptes") faultaround doesn't have dependencies on hardware accessed bit, so let's revert this one too. Link: http://lkml.kernel.org/r/1465893750-44080-3-git-send-email-kirill.shutemov@linux.intel.comSigned-off-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michal Hocko <mhocko@suse.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Vinayak Menon <vinmenon@codeaurora.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by:
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Kirill A. Shutemov authored
This reverts commit 5c0a85fa. The commit causes ~6% regression in unixbench. Let's revert it for now and consider other solution for reclaim problem later. Link: http://lkml.kernel.org/r/1465893750-44080-2-git-send-email-kirill.shutemov@linux.intel.comSigned-off-by:
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Antoine Tenart authored
There are different versions of Boris' name and email in the log, and one typo. Add his emails in mailmap to have all of his contributions under the same name/email tuple. Link: http://lkml.kernel.org/r/20160609130323.27706-2-antoine.tenart@free-electrons.comSigned-off-by:
Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by:
Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by:
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Antoine Tenart authored
I used "Antoine TÃ
© nart" at first but then moved to a name without accent as this cause some issues from time to time... Add my email in the mailmap file to have a consistent shortlog output. Link: http://lkml.kernel.org/r/20160609130323.27706-1-antoine.tenart@free-electrons.comSigned-off-by: -
Mel Gorman authored
Commit d0164adc ("mm, page_alloc: distinguish between being unable to sleep, unwilling to sleep and avoiding waking kswapd") modified __GFP_WAIT to explicitly identify the difference between atomic callers and those that were unwilling to sleep. Later the definition was removed entirely. The GFP_RECLAIM_MASK is the set of flags that affect watermark checking and reclaim behaviour but __GFP_ATOMIC was never added. Without it, atomic users of the slab allocator strip the __GFP_ATOMIC flag and cannot access the page allocator atomic reserves. This patch addresses the problem. The user-visible impact depends on the workload but potentially atomic allocations unnecessarily fail without this path. Link: http://lkml.kernel.org/r/20160610093832.GK2527@techsingularity.netSigned-off-by:
Mel Gorman <mgorman@techsingularity.net> Reported-by:
Marcin Wojtas <mw@semihalf.com> Acked-by:
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Andrey Ryabinin authored
Currently we may put reserved by mempool elements into quarantine via kasan_kfree(). This is totally wrong since quarantine may really free these objects. So when mempool will try to use such element, use-after-free will happen. Or mempool may decide that it no longer need that element and double-free it. So don't put object into quarantine in kasan_kfree(), just poison it. Rename kasan_kfree() to kasan_poison_kfree() to respect that. Also, we shouldn't use kasan_slab_alloc()/kasan_krealloc() in kasan_unpoison_element() because those functions may update allocation stacktrace. This would be wrong for the most of the remove_element call sites. (The only call site where we may want to update alloc stacktrace is in mempool_alloc(). Kmemleak solves this by calling kmemleak_update_trace(), so we could make something like that too. But this is out of scope of this patch). Fixes: 55834c59 ("mm: kasan: initial memory quarantine implementation") Link: http://lkml.kernel.org/r/575977C3.1010905@virtuozzo.comSigned-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Reported-by:
Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Acked-by:
Alexander Potapenko <glider@google.com> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Kostya Serebryany <kcc@google.com> Signed-off-by:
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Jon Mason authored
Update the contact info for Muli, clean-up my name, and update the mailing list to the IOMMU mailing list. Link: http://lkml.kernel.org/r/1465493059-11840-2-git-send-email-jdmason@kudzu.usSigned-off-by:
Jon Mason <jdmason@kudzu.us> Cc: Muli Ben-Yehuda <mulix@mulix.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Signed-off-by:
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Michal Hocko authored
jbd2_alloc is explicit about its allocation preferences wrt. the allocation size. Sub page allocations go to the slab allocator and larger are using either the page allocator or vmalloc. This is all good but the logic is unnecessarily complex. 1) as per Ted, the vmalloc fallback is a left-over: : jbd2_alloc is only passed in the bh->b_size, which can't be PAGE_SIZE, so : the code path that calls vmalloc() should never get called. When we : conveted jbd2_alloc() to suppor sub-page size allocations in commit : d2eecb03, there was an assumption that it could be called with a size : greater than PAGE_SIZE, but that's certaily not true today. Moreover vmalloc allocation might even lead to a deadlock because the callers expect GFP_NOFS context while vmalloc is GFP_KERNEL. 2) __GFP_REPEAT for requests <= PAGE_ALLOC_COSTLY_ORDER is ignored since the flag was introduced. Let's simplify the code flow and use the slab allocator for sub-page requests and the page allocator for others. Even though order > 0 is not currently used as per above leave that option open. Link: http://lkml.kernel.org/r/1464599699-30131-18-git-send-email-mhocko@kernel.orgSigned-off-by:
Jan Kara <jack@suse.cz> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. PGALLOC_GFP uses __GFP_REPEAT but it is only used in pte_alloc_one, pte_alloc_one_kernel which does order-0 request. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-17-git-send-email-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pgtable_alloc_one uses __GFP_REPEAT flag for L2_USER_PGTABLE_ORDER but the order is either 0 or 3 if L2_KERNEL_PGTABLE_SHIFT for HPAGE_SHIFT. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-16-git-send-email-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. PGALLOC_GFP uses __GFP_REPEAT but {pgd,pmd}_alloc allocate from {pgd,pmd}_cache but both caches are allocating up to PAGE_SIZE objects. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-15-git-send-email-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. page_table_alloc then uses the flag for a single page allocation. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-14-git-send-email-mhocko@kernel.orgSigned-off-by:
Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. {pud,pmd}_alloc_one is using __GFP_REPEAT but it always allocates from pgtable_cache which is initialzed to PAGE_SIZE objects. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-13-git-send-email-mhocko@kernel.orgSigned-off-by:David S. Miller <davem@davemloft.net> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. {pud,pmd}_alloc_one are allocating from {PGT,PUD}_CACHE initialized in pgtable_cache_init which doesn't have larger than sizeof(void *) << 12 size and that fits into !costly allocation request size. PGALLOC_GFP is used only in radix__pgd_alloc which uses either order-0 or order-4 requests. The first one doesn't need the flag while the second does. Drop __GFP_REPEAT from PGALLOC_GFP and add it for the order-4 one. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-12-git-send-email-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one{_kernel} allocate PTE_ORDER which is 0. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-11-git-send-email-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pmd_alloc_one allocate PMD_ORDER which is 1. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-10-git-send-email-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one{_kernel} allocate PTE_ORDER which is 0. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-9-git-send-email-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one{_kernel}, pmd_alloc_one allocate PTE_ORDER resp. PMD_ORDER but both are not larger than 1. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-8-git-send-email-mhocko@kernel.orgSigned-off-by: -
Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. pte_alloc_one_kernel uses __get_order_pte but this is obviously always zero because BITS_FOR_PTE is not larger than 9 yet the page size is always larger than 4K. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-7-git-send-email-mhocko@kernel.orgSigned-off-by:
Vineet Gupta <vgupta@synopsys.com> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. {pte,pmd,pud}_alloc_one{_kernel}, late_pgtable_alloc use PGALLOC_GFP for __get_free_page (aka order-0). pgd_alloc is slightly more complex because it allocates from pgd_cache if PGD_SIZE != PAGE_SIZE and PGD_SIZE depends on the configuration (CONFIG_ARM64_VA_BITS, PAGE_SHIFT and CONFIG_PGTABLE_LEVELS). As per config PGTABLE_LEVELS int default 2 if ARM64_16K_PAGES && ARM64_VA_BITS_36 default 2 if ARM64_64K_PAGES && ARM64_VA_BITS_42 default 3 if ARM64_64K_PAGES && ARM64_VA_BITS_48 default 3 if ARM64_4K_PAGES && ARM64_VA_BITS_39 default 3 if ARM64_16K_PAGES && ARM64_VA_BITS_47 default 4 if !ARM64_64K_PAGES && ARM64_VA_BITS_48 we should have the following options CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:4 PAGE_SIZE:4k size:4096 pages:1 CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:4 PAGE_SIZE:16k size:16 pages:1 CONFIG_ARM64_VA_BITS:48 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:64k size:512 pages:1 CONFIG_ARM64_VA_BITS:47 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:16k size:16384 pages:1 CONFIG_ARM64_VA_BITS:42 CONFIG_PGTABLE_LEVELS:2 PAGE_SIZE:64k size:65536 pages:1 CONFIG_ARM64_VA_BITS:39 CONFIG_PGTABLE_LEVELS:3 PAGE_SIZE:4k size:4096 pages:1 CONFIG_ARM64_VA_BITS:36 CONFIG_PGTABLE_LEVELS:2 PAGE_SIZE:16k size:16384 pages:1 All of them fit into a single page (aka order-0). This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-6-git-send-email-mhocko@kernel.orgSigned-off-by:Will Deacon <will.deacon@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. efi_alloc_page_tables uses __GFP_REPEAT but it allocates an order-0 page. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-4-git-send-email-mhocko@kernel.orgSigned-off-by:
Matt Fleming <matt@codeblueprint.co.uk> Signed-off-by:
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Michal Hocko authored
__GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. PGALLOC_GFP uses __GFP_REPEAT but none of the allocation which uses this flag is for more than order-0. This means that this flag has never been actually useful here because it has always been used only for PAGE_ALLOC_COSTLY requests. Link: http://lkml.kernel.org/r/1464599699-30131-3-git-send-email-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
This is the third version of the patchset previously sent [1]. I have basically only rebased it on top of 4.7-rc1 tree and dropped "dm: get rid of superfluous gfp flags" which went through dm tree. I am sending it now because it is tree wide and chances for conflicts are reduced considerably when we want to target rc2. I plan to send the next step and rename the flag and move to a better semantic later during this release cycle so we will have a new semantic ready for 4.8 merge window hopefully. Motivation: While working on something unrelated I've checked the current usage of __GFP_REPEAT in the tree. It seems that a majority of the usage is and always has been bogus because __GFP_REPEAT has always been about costly high order allocations while we are using it for order-0 or very small orders very often. It seems that a big pile of them is just a copy&paste when a code has been adopted from one arch to another. I think it makes some sense to get rid of them because they are just making the semantic more unclear. Please note that GFP_REPEAT is documented as * __GFP_REPEAT: Try hard to allocate the memory, but the allocation attempt * _might_ fail. This depends upon the particular VM implementation. while !costly requests have basically nofail semantic. So one could reasonably expect that order-0 request with __GFP_REPEAT will not loop for ever. This is not implemented right now though. I would like to move on with __GFP_REPEAT and define a better semantic for it. $ git grep __GFP_REPEAT origin/master | wc -l 111 $ git grep __GFP_REPEAT | wc -l 36 So we are down to the third after this patch series. The remaining places really seem to be relying on __GFP_REPEAT due to large allocation requests. This still needs some double checking which I will do later after all the simple ones are sorted out. I am touching a lot of arch specific code here and I hope I got it right but as a matter of fact I even didn't compile test for some archs as I do not have cross compiler for them. Patches should be quite trivial to review for stupid compile mistakes though. The tricky parts are usually hidden by macro definitions and thats where I would appreciate help from arch maintainers. [1] http://lkml.kernel.org/r/1461849846-27209-1-git-send-email-mhocko@kernel.org This patch (of 19): __GFP_REPEAT has a rather weak semantic but since it has been introduced around 2.6.12 it has been ignored for low order allocations. Yet we have the full kernel tree with its usage for apparently order-0 allocations. This is really confusing because __GFP_REPEAT is explicitly documented to allow allocation failures which is a weaker semantic than the current order-0 has (basically nofail). Let's simply drop __GFP_REPEAT from those places. This would allow to identify place which really need allocator to retry harder and formulate a more specific semantic for what the flag is supposed to do actually. Link: http://lkml.kernel.org/r/1464599699-30131-2-git-send-email-mhocko@kernel.orgSigned-off-by:
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Anthony Romano authored
When fallocate is interrupted it will undo a range that extends one byte past its range of allocated pages. This can corrupt an in-use page by zeroing out its first byte. Instead, undo using the inclusive byte range. Fixes: 1635f6a7 ("tmpfs: undo fallocation on failure") Link: http://lkml.kernel.org/r/1462713387-16724-1-git-send-email-anthony.romano@coreos.comSigned-off-by:
Anthony Romano <anthony.romano@coreos.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Brandon Philips <brandon@ifup.co> Cc: <stable@vger.kernel.org> Signed-off-by:
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Mike Kravetz authored
The write at the end of the test to restore nr_hugepages to its previous value is failing. This is because it is trying to write the number of bytes in the char array as opposed to the number of bytes in the string. Link: http://lkml.kernel.org/r/1465331205-3284-1-git-send-email-mike.kravetz@oracle.comSigned-off-by:
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Tetsuo Handa authored
Since commit 36324a99 ("oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space") changed to use find_lock_task_mm() for finding a mm_struct to reap, it is guaranteed that mm->mm_users > 0 because find_lock_task_mm() returns a task_struct with ->mm != NULL. Therefore, we can safely use atomic_inc(). Link: http://lkml.kernel.org/r/1465024759-8074-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by:
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Tetsuo Handa authored
Commit e2fe1456 ("oom_reaper: close race with exiting task") reduced frequency of needlessly selecting next OOM victim, but was calling mmput_async() when atomic_inc_not_zero() failed. Link: http://lkml.kernel.org/r/1464423365-5555-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jpSigned-off-by:
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- 24 Jun, 2016 4 commits
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git://git.infradead.org/linux-ubifsLinus Torvalds authored
Pull UBI/UBIFS fixes from Richard Weinberger: "This contains fixes for two critical bugs in UBI and UBIFS: - fix the possibility of losing data upon a power cut when UBI tries to recover from a write error - fix page migration on UBIFS. It turned out that the default page migration function is not suitable for UBIFS" * tag 'upstream-4.7-rc5' of git://git.infradead.org/linux-ubifs: UBIFS: Implement ->migratepage() mm: Export migrate_page_move_mapping and migrate_page_copy ubi: Make recover_peb power cut aware gpio: make library immune to error pointers gpio: make sure gpiod_to_irq() returns negative on NULL desc gpio: 104-idi-48: Fix missing spin_lock_init for ack_lock -
git://people.freedesktop.org/~airlied/linuxLinus Torvalds authored
Pull drm fixes from Dave Airlie: "This is the drm fixes tree for 4.7-rc5. It's a bit larger than normal, due to fixes for production AMD Polaris GPUs. We only merged support for these in 4.7-rc1 so it would be good if we got all the fixes into final. The changes don't hit any other hardware. Other than the amdgpu Polaris changes: - A single fix for atomic modesetting WARN - Nouveau fix for when fbdev is disabled - i915 fixes for FBC on Haswell and displayport regression - Exynos fix for a display panel regression and some other minor changes - Atmel fixes for scaling and OF graph interaction - Allwiinner build, warning and probing fixes - AMD GPU non-polaris fix for num_rbs and some minor fixes Also I've just moved house, and my new place is Internet challenged due to incompetent incumbent ISPs, hopefully sorted out in a couple of weeks, so I might not be too responsive over the next while. It also helps Daniel is on holidays for those couple of weeks as well" * tag 'drm-fixes-for-v4.7-rc5' of git://people.freedesktop.org/~airlied/linux: (38 commits) drm/atomic: Make drm_atomic_legacy_backoff reset crtc->acquire_ctx drm/nouveau: fix for disabled fbdev emulation drm/i915/fbc: Disable on HSW by default for now drm/i915: Revert DisplayPort fast link training feature drm/amd/powerplay: enable clock stretch feature for polaris drm/amdgpu/gfx8: update golden setting for polaris10 drm/amd/powerplay: enable avfs feature for polaris drm/amdgpu/atombios: add avfs struct for Polaris10/11 drm/amd/powerplay: add avfs related define for polaris drm/amd/powrplay: enable stutter_mode for polaris. drm/amd/powerplay: disable UVD SMU handshake for MCLK. drm/amd/powerplay: initialize variables which were missed. drm/amd/powerplay: enable PowerContainment feature for polaris10/11. drm/amd/powerplay: need to notify system bios pcie device ready drm/amd/powerplay: fix bug that function parameter was incorect. drm/amd/powerplay: fix logic error. drm: atmel-hlcdc: Fix OF graph parsing drm: atmel-hlcdc: actually disable scaling when no scaling is required drm/amdgpu: initialize amdgpu_cgs_acpi_eval_object result value drm/amdgpu: precedence bug in amdgpu_device_init() ...
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git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pciLinus Torvalds authored
Pull PCI fix from Bjorn Helgaas: "Here's a small fix for v4.7. This problem was actually introduced in v4.6 when we unified Kconfig, making PCIe support available everywhere including sparc, where config reads into unaligned buffers cause warnings. This fix is from Dave Miller. As a reminder, any future PCI fixes for v4.7 will probably come from Alex Williamson, since I'll be on vacation for most of the rest of this cycle. I should be back about the time the merge window opens" * tag 'pci-v4.7-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: PCI: Fix unaligned accesses in VC code
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Maarten Lankhorst authored
Atomic updates may acquire more state than initially locked through drm_modeset_lock_crtc, running with heavy stress can cause a WARN_ON(crtc->acquire_ctx) in drm_modeset_lock_crtc: [ 601.491296] ------------[ cut here ]------------ [ 601.491366] WARNING: CPU: 0 PID: 2411 at drivers/gpu/drm/drm_modeset_lock.c:191 drm_modeset_lock_crtc+0xeb/0xf0 [drm] [ 601.491369] Modules linked in: drm i915 drm_kms_helper [ 601.491414] CPU: 0 PID: 2411 Comm: kms_cursor_lega Tainted: G U 4.7.0-rc4-patser+ #4798 [ 601.491417] Hardware name: Intel Corporation Skylake Client [ 601.491420] 0000000000000000 ffff88044d153c98 ffffffff812ead28 0000000000000000 [ 601.491425] 0000000000000000 ffff88044d153cd8 ffffffff810868e6 000000bf58058030 [ 601.491431] ffff880088b415e8 ffff880458058030 ffff88008a271548 ffff88008a271568 [ 601.491436] Call Trace: [ 601.491443] [<ffffffff812ead28>] dump_stack+0x4d/0x65 [ 601.491447] [<ffffffff810868e6>] __warn+0xc6/0xe0 [ 601.491452] [<ffffffff81086968>] warn_slowpath_null+0x18/0x20 [ 601.491472] [<ffffffffc00d4ffb>] drm_modeset_lock_crtc+0xeb/0xf0 [drm] [ 601.491491] [<ffffffffc00c5526>] drm_mode_cursor_common+0x66/0x180 [drm] [ 601.491509] [<ffffffffc00c91cc>] drm_mode_cursor_ioctl+0x3c/0x40 [drm] [ 601.491524] [<ffffffffc00bc94d>] drm_ioctl+0x14d/0x530 [drm] [ 601.491540] [<ffffffffc00c9190>] ? drm_mode_setcrtc+0x520/0x520 [drm] [ 601.491545] [<ffffffff81176aeb>] ? handle_mm_fault+0x106b/0x1430 [ 601.491550] [<ffffffff81108441>] ? stop_one_cpu+0x61/0x70 [ 601.491556] [<ffffffff811bb71d>] do_vfs_ioctl+0x8d/0x570 [ 601.491560] [<ffffffff81290d7e>] ? security_file_ioctl+0x3e/0x60 [ 601.491565] [<ffffffff811bbc74>] SyS_ioctl+0x74/0x80 [ 601.491571] [<ffffffff810e321c>] ? posix_get_monotonic_raw+0xc/0x10 [ 601.491576] [<ffffffff8175b11b>] entry_SYSCALL_64_fastpath+0x13/0x8f [ 601.491581] ---[ end trace 56f3d3d85f000d00 ]--- For good measure, test mode_config.acquire_ctx too, although this should never happen. Testcase: kms_cursor_legacy Signed-off-by:
Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Reviewed-by:
Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org Signed-off-by:
Dave Airlie <airlied@redhat.com>
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