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2016-06-03mm, page_alloc: recalculate the preferred zoneref if the context can ignore ↵Mel Gorman
memory policies The optimistic fast path may use cpuset_current_mems_allowed instead of of a NULL nodemask supplied by the caller for cpuset allocations. The preferred zone is calculated on this basis for statistic purposes and as a starting point in the zonelist iterator. However, if the context can ignore memory policies due to being atomic or being able to ignore watermarks then the starting point in the zonelist iterator is no longer correct. This patch resets the zonelist iterator in the allocator slowpath if the context can ignore memory policies. This will alter the zone used for statistics but only after it is known that it makes sense for that context. Resetting it before entering the slowpath would potentially allow an ALLOC_CPUSET allocation to be accounted for against the wrong zone. Note that while nodemask is not explicitly set to the original nodemask, it would only have been overwritten if cpuset_enabled() and it was reset before the slowpath was entered. Link: http://lkml.kernel.org/r/20160602103936.GU2527@techsingularity.net Fixes: c33d6c06f60f710 ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm, page_alloc: reset zonelist iterator after resetting fair zone allocation ↵Mel Gorman
policy Geert Uytterhoeven reported the following problem that bisected to commit c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") on m68k/ARAnyM BUG: scheduling while atomic: cron/668/0x10c9a0c0 Modules linked in: CPU: 0 PID: 668 Comm: cron Not tainted 4.6.0-atari-05133-gc33d6c06f60f710f #364 Call Trace: [<0003d7d0>] __schedule_bug+0x40/0x54 __schedule+0x312/0x388 __schedule+0x0/0x388 prepare_to_wait+0x0/0x52 schedule+0x64/0x82 schedule_timeout+0xda/0x104 set_next_entity+0x18/0x40 pick_next_task_fair+0x78/0xda io_schedule_timeout+0x36/0x4a bit_wait_io+0x0/0x40 bit_wait_io+0x12/0x40 __wait_on_bit+0x46/0x76 wait_on_page_bit_killable+0x64/0x6c bit_wait_io+0x0/0x40 wake_bit_function+0x0/0x4e __lock_page_or_retry+0xde/0x124 do_scan_async+0x114/0x17c lookup_swap_cache+0x24/0x4e handle_mm_fault+0x626/0x7de find_vma+0x0/0x66 down_read+0x0/0xe wait_on_page_bit_killable_timeout+0x77/0x7c find_vma+0x16/0x66 do_page_fault+0xe6/0x23a res_func+0xa3c/0x141a buserr_c+0x190/0x6d4 res_func+0xa3c/0x141a buserr+0x20/0x28 res_func+0xa3c/0x141a buserr+0x20/0x28 The relationship is not obvious but it's due to a failure to rescan the full zonelist after the fair zone allocation policy exhausts the batch count. While this is a functional problem, it's also a performance issue. A page allocator microbenchmark showed the following 4.7.0-rc1 4.7.0-rc1 vanilla reset-v1r2 Min alloc-odr0-1 327.00 ( 0.00%) 326.00 ( 0.31%) Min alloc-odr0-2 235.00 ( 0.00%) 235.00 ( 0.00%) Min alloc-odr0-4 198.00 ( 0.00%) 198.00 ( 0.00%) Min alloc-odr0-8 170.00 ( 0.00%) 170.00 ( 0.00%) Min alloc-odr0-16 156.00 ( 0.00%) 156.00 ( 0.00%) Min alloc-odr0-32 150.00 ( 0.00%) 150.00 ( 0.00%) Min alloc-odr0-64 146.00 ( 0.00%) 146.00 ( 0.00%) Min alloc-odr0-128 145.00 ( 0.00%) 145.00 ( 0.00%) Min alloc-odr0-256 155.00 ( 0.00%) 155.00 ( 0.00%) Min alloc-odr0-512 168.00 ( 0.00%) 165.00 ( 1.79%) Min alloc-odr0-1024 175.00 ( 0.00%) 174.00 ( 0.57%) Min alloc-odr0-2048 180.00 ( 0.00%) 180.00 ( 0.00%) Min alloc-odr0-4096 187.00 ( 0.00%) 186.00 ( 0.53%) Min alloc-odr0-8192 190.00 ( 0.00%) 190.00 ( 0.00%) Min alloc-odr0-16384 191.00 ( 0.00%) 191.00 ( 0.00%) Min alloc-odr1-1 736.00 ( 0.00%) 445.00 ( 39.54%) Min alloc-odr1-2 343.00 ( 0.00%) 335.00 ( 2.33%) Min alloc-odr1-4 277.00 ( 0.00%) 270.00 ( 2.53%) Min alloc-odr1-8 238.00 ( 0.00%) 233.00 ( 2.10%) Min alloc-odr1-16 224.00 ( 0.00%) 218.00 ( 2.68%) Min alloc-odr1-32 210.00 ( 0.00%) 208.00 ( 0.95%) Min alloc-odr1-64 207.00 ( 0.00%) 203.00 ( 1.93%) Min alloc-odr1-128 276.00 ( 0.00%) 202.00 ( 26.81%) Min alloc-odr1-256 206.00 ( 0.00%) 202.00 ( 1.94%) Min alloc-odr1-512 207.00 ( 0.00%) 202.00 ( 2.42%) Min alloc-odr1-1024 208.00 ( 0.00%) 205.00 ( 1.44%) Min alloc-odr1-2048 213.00 ( 0.00%) 212.00 ( 0.47%) Min alloc-odr1-4096 218.00 ( 0.00%) 216.00 ( 0.92%) Min alloc-odr1-8192 341.00 ( 0.00%) 219.00 ( 35.78%) Note that order-0 allocations are unaffected but higher orders get a small boost from this patch and a large reduction in system CPU usage overall as can be seen here: 4.7.0-rc1 4.7.0-rc1 vanilla reset-v1r2 User 85.32 86.31 System 2221.39 2053.36 Elapsed 2368.89 2202.47 Fixes: c33d6c06f60f ("mm, page_alloc: avoid looking up the first zone in a zonelist twice") Link: http://lkml.kernel.org/r/20160531100848.GR2527@techsingularity.net Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm, oom_reaper: do not use siglock in try_oom_reaper()Michal Hocko
Oleg has noted that siglock usage in try_oom_reaper is both pointless and dangerous. signal_group_exit can be checked lockless. The problem is that sighand becomes NULL in __exit_signal so we can crash. Fixes: 3ef22dfff239 ("oom, oom_reaper: try to reap tasks which skip regular OOM killer path") Link: http://lkml.kernel.org/r/1464679423-30218-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm, page_alloc: prevent infinite loop in buffered_rmqueue()Vlastimil Babka
In DEBUG_VM kernel, we can hit infinite loop for order == 0 in buffered_rmqueue() when check_new_pcp() returns 1, because the bad page is never removed from the pcp list. Fix this by removing the page before retrying. Also we don't need to check if page is non-NULL, because we simply grab it from the list which was just tested for being non-empty. Fixes: 479f854a207c ("mm, page_alloc: defer debugging checks of pages allocated from the PCP") Link: http://lkml.kernel.org/r/20160530090154.GM2527@techsingularity.net Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm/z3fold.c: avoid modifying HEADLESS page and minor cleanupVitaly Wool
Fix erroneous z3fold header access in a HEADLESS page in reclaim function, and change one remaining direct handle-to-buddy conversion to use the appropriate helper. Link: http://lkml.kernel.org/r/5748706F.9020208@gmail.com Signed-off-by: Vitaly Wool <vitalywool@gmail.com> Reviewed-by: Dan Streetman <ddstreet@ieee.org> Cc: Seth Jennings <sjenning@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03memcg: add RCU locking around css_for_each_descendant_pre() in ↵Tejun Heo
memcg_offline_kmem() memcg_offline_kmem() may be called from memcg_free_kmem() after a css init failure. memcg_free_kmem() is a ->css_free callback which is called without cgroup_mutex and memcg_offline_kmem() ends up using css_for_each_descendant_pre() without any locking. Fix it by adding rcu read locking around it. mkdir: cannot create directory `65530': No space left on device =============================== [ INFO: suspicious RCU usage. ] 4.6.0-work+ #321 Not tainted ------------------------------- kernel/cgroup.c:4008 cgroup_mutex or RCU read lock required! [ 527.243970] other info that might help us debug this: [ 527.244715] rcu_scheduler_active = 1, debug_locks = 0 2 locks held by kworker/0:5/1664: #0: ("cgroup_destroy"){.+.+..}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0 #1: ((&css->destroy_work)#3){+.+...}, at: [<ffffffff81060ab5>] process_one_work+0x165/0x4a0 [ 527.248098] stack backtrace: CPU: 0 PID: 1664 Comm: kworker/0:5 Not tainted 4.6.0-work+ #321 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.9.1-1.fc24 04/01/2014 Workqueue: cgroup_destroy css_free_work_fn Call Trace: dump_stack+0x68/0xa1 lockdep_rcu_suspicious+0xd7/0x110 css_next_descendant_pre+0x7d/0xb0 memcg_offline_kmem.part.44+0x4a/0xc0 mem_cgroup_css_free+0x1ec/0x200 css_free_work_fn+0x49/0x5e0 process_one_work+0x1c5/0x4a0 worker_thread+0x49/0x490 kthread+0xea/0x100 ret_from_fork+0x1f/0x40 Link: http://lkml.kernel.org/r/20160526203018.GG23194@mtj.duckdns.org Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: <stable@vger.kernel.org> [4.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm: check the return value of lookup_page_ext for all call sitesYang Shi
Per the discussion with Joonsoo Kim [1], we need check the return value of lookup_page_ext() for all call sites since it might return NULL in some cases, although it is unlikely, i.e. memory hotplug. Tested with ltp with "page_owner=0". [1] http://lkml.kernel.org/r/20160519002809.GA10245@js1304-P5Q-DELUXE [akpm@linux-foundation.org: fix build-breaking typos] [arnd@arndb.de: fix build problems from lookup_page_ext] Link: http://lkml.kernel.org/r/6285269.2CksypHdYp@wuerfel [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/1464023768-31025-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-06-03mm: fix overflow in vm_map_ram()Guillermo Julián Moreno
When remapping pages accounting for 4G or more memory space, the operation 'count << PAGE_SHIFT' overflows as it is performed on an integer. Solution: cast before doing the bitshift. [akpm@linux-foundation.org: fix vm_unmap_ram() also] [akpm@linux-foundation.org: fix vmap() as well, per Guillermo] Link: http://lkml.kernel.org/r/etPan.57175fb3.7a271c6b.2bd@naudit.es Signed-off-by: Guillermo Julián Moreno <guillermo.julian@naudit.es> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-28Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Followups to the parallel lookup work: - update docs - restore killability of the places that used to take ->i_mutex killably now that we have down_write_killable() merged - Additionally, it turns out that I missed a prerequisite for security_d_instantiate() stuff - ->getxattr() wasn't the only thing that could be called before dentry is attached to inode; with smack we needed the same treatment applied to ->setxattr() as well" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->setxattr() to passing dentry and inode separately switch xattr_handler->set() to passing dentry and inode separately restore killability of old mutex_lock_killable(&inode->i_mutex) users add down_write_killable_nested() update D/f/directory-locking
2016-05-27mm: remove more IS_ERR_VALUE abusesLinus Torvalds
The do_brk() and vm_brk() return value was "unsigned long" and returned the starting address on success, and an error value on failure. The reasons are entirely historical, and go back to it basically behaving like the mmap() interface does. However, nobody actually wanted that interface, and it causes totally pointless IS_ERR_VALUE() confusion. What every single caller actually wants is just the simpler integer return of zero for success and negative error number on failure. So just convert to that much clearer and more common calling convention, and get rid of all the IS_ERR_VALUE() uses wrt vm_brk(). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: fix section mismatch warningLinus Torvalds
The register_page_bootmem_info_node() function needs to be marked __init in order to avoid a new warning introduced by commit f65e91df25aa ("mm: use early_pfn_to_nid in register_page_bootmem_info_node"). Otherwise you'll get a warning about how a non-init function calls early_pfn_to_nid (which is __meminit) Cc: Yang Shi <yang.shi@linaro.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: disable DEFERRED_STRUCT_PAGE_INIT on !NO_BOOTMEMGavin Shan
When we have !NO_BOOTMEM, the deferred page struct initialization doesn't work well because the pages reserved in bootmem are released to the page allocator uncoditionally. It causes memory corruption and system crash eventually. As Mel suggested, the bootmem is retiring slowly. We fix the issue by simply hiding DEFERRED_STRUCT_PAGE_INIT when bootmem is enabled. Link: http://lkml.kernel.org/r/1460602170-5821-1-git-send-email-gwshan@linux.vnet.ibm.com Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Acked-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm/memcontrol.c: move comments for get_mctgt_type() to proper positionLi RongQing
Move the comments for get_mctgt_type() to be before get_mctgt_type() implementation. Link: http://lkml.kernel.org/r/1463644638-7446-1-git-send-email-roy.qing.li@gmail.com Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Michal Hocko <mhocko@suse.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>
2016-05-27mm/memcontrol.c: fix the margin computation in mem_cgroup_margin()Li RongQing
mem_cgroup_margin() might return (memory.limit - memory_count) when the memsw.limit is in excess. This doesn't happen usually because we do not allow excess on hard limits and (memory.limit <= memsw.limit), but __GFP_NOFAIL charges can force the charge and cause the excess when no memory is really swappable (swap is full or no anonymous memory is left). [mhocko@suse.com: rewrote changelog] Link: http://lkml.kernel.org/r/20160525155122.GK20132@dhcp22.suse.cz Link: http://lkml.kernel.org/r/1464068266-27736-1-git-send-email-roy.qing.li@gmail.com Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.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>
2016-05-27mm/cma: silence warnings due to max() usageStephen Rothwell
pageblock_order can be (at least) an unsigned int or an unsigned long depending on the kernel config and architecture, so use max_t(unsigned long, ...) when comparing it. fixes these warnings: In file included from include/asm-generic/bug.h:13:0, from arch/powerpc/include/asm/bug.h:127, from include/linux/bug.h:4, from include/linux/mmdebug.h:4, from include/linux/mm.h:8, from include/linux/memblock.h:18, from mm/cma.c:28: mm/cma.c: In function 'cma_init_reserved_mem': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ mm/cma.c:186:27: note: in expansion of macro 'max' alignment = PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order); ^ mm/cma.c: In function 'cma_declare_contiguous': include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:9: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ include/linux/kernel.h:748:17: warning: comparison of distinct pointer types lacks a cast (void) (&_max1 == &_max2); ^ include/linux/kernel.h:747:21: note: in definition of macro 'max' typeof(y) _max2 = (y); ^ mm/cma.c:270:29: note: in expansion of macro 'max' (phys_addr_t)PAGE_SIZE << max(MAX_ORDER - 1, pageblock_order)); ^ [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160526150748.5be38a4f@canb.auug.org.au Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: thp: avoid false positive VM_BUG_ON_PAGE in page_move_anon_rmap()Kirill A. Shutemov
If page_move_anon_rmap() is refiling a pmd-splitted THP mapped in a tail page from a pte, the "address" must be THP aligned in order for the page->index bugcheck to pass in the CONFIG_DEBUG_VM=y builds. Link: http://lkml.kernel.org/r/1464253620-106404-1-git-send-email-kirill.shutemov@linux.intel.com Fixes: 6d0a07edd17c ("mm: thp: calculate the mapcount correctly for THP pages during WP faults") Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Mika Westerberg <mika.westerberg@linux.intel.com> Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: <stable@vger.kernel.org> [4.5] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27oom_reaper: close race with exiting taskMichal Hocko
Tetsuo has reported: Out of memory: Kill process 443 (oleg's-test) score 855 or sacrifice child Killed process 443 (oleg's-test) total-vm:493248kB, anon-rss:423880kB, file-rss:4kB, shmem-rss:0kB sh invoked oom-killer: gfp_mask=0x24201ca(GFP_HIGHUSER_MOVABLE|__GFP_COLD), order=0, oom_score_adj=0 sh cpuset=/ mems_allowed=0 CPU: 2 PID: 1 Comm: sh Not tainted 4.6.0-rc7+ #51 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/31/2013 Call Trace: dump_stack+0x85/0xc8 dump_header+0x5b/0x394 oom_reaper: reaped process 443 (oleg's-test), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB In other words: __oom_reap_task exit_mm atomic_inc_not_zero tsk->mm = NULL mmput atomic_dec_and_test # > 0 exit_oom_victim # New victim will be # selected <OOM killer invoked> # no TIF_MEMDIE task so we can select a new one unmap_page_range # to release the memory The race exists even without the oom_reaper because anybody who pins the address space and gets preempted might race with exit_mm but oom_reaper made this race more probable. We can address the oom_reaper part by using oom_lock for __oom_reap_task because this would guarantee that a new oom victim will not be selected if the oom reaper might race with the exit path. This doesn't solve the original issue, though, because somebody else still might be pinning mm_users and so __mmput won't be called to release the memory but that is not really realiably solvable because the task will get away from the oom sight as soon as it is unhashed from the task_list and so we cannot guarantee a new victim won't be selected. [akpm@linux-foundation.org: fix use of unused `mm', Per Stephen] [akpm@linux-foundation.org: coding-style fixes] Fixes: aac453635549 ("mm, oom: introduce oom reaper") Link: http://lkml.kernel.org/r/1464271493-20008-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: use early_pfn_to_nid in register_page_bootmem_info_nodeYang Shi
register_page_bootmem_info_node() is invoked in mem_init(), so it will be called before page_alloc_init_late() if DEFERRED_STRUCT_PAGE_INIT is enabled. But, pfn_to_nid() depends on memmap which won't be fully setup until page_alloc_init_late() is done, so replace pfn_to_nid() by early_pfn_to_nid(). Link: http://lkml.kernel.org/r/1464210007-30930-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: use early_pfn_to_nid in page_ext_initYang Shi
page_ext_init() checks suitable pages with pfn_to_nid(), but pfn_to_nid() depends on memmap which will not be setup fully until page_alloc_init_late() is done. Use early_pfn_to_nid() instead of pfn_to_nid() so that page extension could be still used early even though CONFIG_ DEFERRED_STRUCT_PAGE_INIT is enabled and catch early page allocation call sites. Suggested by Joonsoo Kim [1], this fix basically undoes the change introduced by commit b8f1a75d61d840 ("mm: call page_ext_init() after all struct pages are initialized") and fixes the same problem with a better approach. [1] http://lkml.kernel.org/r/CAAmzW4OUmyPwQjvd7QUfc6W1Aic__TyAuH80MLRZNMxKy0-wPQ@mail.gmail.com Link: http://lkml.kernel.org/r/1464198689-23458-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27mm: oom: do not reap task if there are live threads in threadgroupVladimir Davydov
If the current process is exiting, we don't invoke oom killer, instead we give it access to memory reserves and try to reap its mm in case nobody is going to use it. There's a mistake in the code performing this check - we just ignore any process of the same thread group no matter if it is exiting or not - see try_oom_reaper. Fix it. Link: http://lkml.kernel.org/r/1464087628-7318-1-git-send-email-vdavydov@virtuozzo.com Fixes: 3ef22dfff239 ("oom, oom_reaper: try to reap tasks which skip regular OOM killer path")Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27switch xattr_handler->set() to passing dentry and inode separatelyAl Viro
preparation for similar switch in ->setxattr() (see the next commit for rationale). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-27Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: drivers/pinctrl/intel/pinctrl-baytrail.c: fix build with gcc-4.4 update "mm/zsmalloc: don't fail if can't create debugfs info" dma-debug: avoid spinlock recursion when disabling dma-debug mm: oom_reaper: remove some bloat memcg: fix mem_cgroup_out_of_memory() return value. ocfs2: fix improper handling of return errno mm: slub: remove unused virt_to_obj() mm: kasan: remove unused 'reserved' field from struct kasan_alloc_meta mm: make CONFIG_DEFERRED_STRUCT_PAGE_INIT depends on !FLATMEM explicitly seqlock: fix raw_read_seqcount_latch()
2016-05-27Merge tag 'dax-locking-for-4.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull DAX locking updates from Ross Zwisler: "Filesystem DAX locking for 4.7 - We use a bit in an exceptional radix tree entry as a lock bit and use it similarly to how page lock is used for normal faults. This fixes races between hole instantiation and read faults of the same index. - Filesystem DAX PMD faults are disabled, and will be re-enabled when PMD locking is implemented" * tag 'dax-locking-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: dax: Remove i_mmap_lock protection dax: Use radix tree entry lock to protect cow faults dax: New fault locking dax: Allow DAX code to replace exceptional entries dax: Define DAX lock bit for radix tree exceptional entry dax: Make huge page handling depend of CONFIG_BROKEN dax: Fix condition for filling of PMD holes
2016-05-26update "mm/zsmalloc: don't fail if can't create debugfs info"Dan Streetman
Some updates to commit d34f615720d1 ("mm/zsmalloc: don't fail if can't create debugfs info"): - add pr_warn to all stat failure cases - do not prevent module loading on stat failure Link: http://lkml.kernel.org/r/1463671123-5479-1-git-send-email-ddstreet@ieee.org Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reviewed-by: Ganesh Mahendran <opensource.ganesh@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-26memcg: fix mem_cgroup_out_of_memory() return value.Tetsuo Handa
mem_cgroup_out_of_memory() is returning "true" if it finds a TIF_MEMDIE task after an eligible task was found, "false" if it found a TIF_MEMDIE task before an eligible task is found. This difference confuses memory_max_write() which checks the return value of mem_cgroup_out_of_memory(). Since memory_max_write() wants to continue looping, mem_cgroup_out_of_memory() should return "true" in this case. This patch sets a dummy pointer in order to return "true". Link: http://lkml.kernel.org/r/1463753327-5170-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov@virtuozzo.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>
2016-05-26mm: kasan: remove unused 'reserved' field from struct kasan_alloc_metaAndrey Ryabinin
Commit cd11016e5f52 ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB") added 'reserved' field, but never used it. Link: http://lkml.kernel.org/r/1464021054-2307-1-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-26mm: make CONFIG_DEFERRED_STRUCT_PAGE_INIT depends on !FLATMEM explicitlyYang Shi
Per the suggestion from Michal Hocko [1], DEFERRED_STRUCT_PAGE_INIT requires some ordering wrt other initialization operations, e.g. page_ext_init has to happen after the whole memmap is initialized properly. For SPARSEMEM this requires to wait for page_alloc_init_late. Other memory models (e.g. flatmem) might have different initialization layouts (page_ext_init_flatmem). Currently DEFERRED_STRUCT_PAGE_INIT depends on MEMORY_HOTPLUG which in turn depends on SPARSEMEM || X86_64_ACPI_NUMA depends on ARCH_ENABLE_MEMORY_HOTPLUG and X86_64_ACPI_NUMA depends on NUMA which in turn disable FLATMEM memory model: config ARCH_FLATMEM_ENABLE def_bool y depends on X86_32 && !NUMA so FLATMEM is ruled out via dependency maze. Be explicit and disable FLATMEM for DEFERRED_STRUCT_PAGE_INIT so that we do not reintroduce subtle initialization bugs [1] http://lkml.kernel.org/r/20160523073157.GD2278@dhcp22.suse.cz Link: http://lkml.kernel.org/r/1464027356-32282-1-git-send-email-yang.shi@linaro.org Signed-off-by: Yang Shi <yang.shi@linaro.org> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-24Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge yet more updates from Andrew Morton: - Oleg's "wait/ptrace: assume __WALL if the child is traced". It's a kernel-based workaround for existing userspace issues. - A few hotfixes - befs cleanups - nilfs2 updates - sys_wait() changes - kexec updates - kdump - scripts/gdb updates - the last of the MM queue - a few other misc things * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (84 commits) kgdb: depends on VT drm/amdgpu: make amdgpu_mn_get wait for mmap_sem killable drm/radeon: make radeon_mn_get wait for mmap_sem killable drm/i915: make i915_gem_mmap_ioctl wait for mmap_sem killable uprobes: wait for mmap_sem for write killable prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable exec: make exec path waiting for mmap_sem killable aio: make aio_setup_ring killable coredump: make coredump_wait wait for mmap_sem for write killable vdso: make arch_setup_additional_pages wait for mmap_sem for write killable ipc, shm: make shmem attach/detach wait for mmap_sem killable mm, fork: make dup_mmap wait for mmap_sem for write killable mm, proc: make clear_refs killable mm: make vm_brk killable mm, elf: handle vm_brk error mm, aout: handle vm_brk failures mm: make vm_munmap killable mm: make vm_mmap killable mm: make mmap_sem for write waits killable for mm syscalls MAINTAINERS: add co-maintainer for scripts/gdb ...
2016-05-24mm: make vm_brk killableMichal Hocko
Now that all the callers handle vm_brk failure we can change it wait for mmap_sem killable to help oom_reaper to not get blocked just because vm_brk gets blocked behind mmap_sem readers. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-24mm: make vm_munmap killableMichal Hocko
Almost all current users of vm_munmap are ignoring the return value and so they do not handle potential error. This means that some VMAs might stay behind. This patch doesn't try to solve those potential problems. Quite contrary it adds a new failure mode by using down_write_killable in vm_munmap. This should be safer than other failure modes, though, because the process is guaranteed to die as soon as it leaves the kernel and exit_mmap will clean the whole address space. This will help in the OOM conditions when the oom victim might be stuck waiting for the mmap_sem for write which in turn can block oom_reaper which relies on the mmap_sem for read to make a forward progress and reclaim the address space of the victim. Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-24mm: make vm_mmap killableMichal Hocko
All the callers of vm_mmap seem to check for the failure already and bail out in one way or another on the error which means that we can change it to use killable version of vm_mmap_pgoff and return -EINTR if the current task gets killed while waiting for mmap_sem. This also means that vm_mmap_pgoff can be killable by default and drop the additional parameter. This will help in the OOM conditions when the oom victim might be stuck waiting for the mmap_sem for write which in turn can block oom_reaper which relies on the mmap_sem for read to make a forward progress and reclaim the address space of the victim. Please note that load_elf_binary is ignoring vm_mmap error for current->personality & MMAP_PAGE_ZERO case but that shouldn't be a problem because the address is not used anywhere and we never return to the userspace if we got killed. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-24mm: make mmap_sem for write waits killable for mm syscallsMichal Hocko
This is a follow up work for oom_reaper [1]. As the async OOM killing depends on oom_sem for read we would really appreciate if a holder for write didn't stood in the way. This patchset is changing many of down_write calls to be killable to help those cases when the writer is blocked and waiting for readers to release the lock and so help __oom_reap_task to process the oom victim. Most of the patches are really trivial because the lock is help from a shallow syscall paths where we can return EINTR trivially and allow the current task to die (note that EINTR will never get to the userspace as the task has fatal signal pending). Others seem to be easy as well as the callers are already handling fatal errors and bail and return to userspace which should be sufficient to handle the failure gracefully. I am not familiar with all those code paths so a deeper review is really appreciated. As this work is touching more areas which are not directly connected I have tried to keep the CC list as small as possible and people who I believed would be familiar are CCed only to the specific patches (all should have received the cover though). This patchset is based on linux-next and it depends on down_write_killable for rw_semaphores which got merged into tip locking/rwsem branch and it is merged into this next tree. I guess it would be easiest to route these patches via mmotm because of the dependency on the tip tree but if respective maintainers prefer other way I have no objections. I haven't covered all the mmap_write(mm->mmap_sem) instances here $ git grep "down_write(.*\<mmap_sem\>)" next/master | wc -l 98 $ git grep "down_write(.*\<mmap_sem\>)" | wc -l 62 I have tried to cover those which should be relatively easy to review in this series because this alone should be a nice improvement. Other places can be changed on top. [0] http://lkml.kernel.org/r/1456752417-9626-1-git-send-email-mhocko@kernel.org [1] http://lkml.kernel.org/r/1452094975-551-1-git-send-email-mhocko@kernel.org [2] http://lkml.kernel.org/r/1456750705-7141-1-git-send-email-mhocko@kernel.org This patch (of 18): This is the first step in making mmap_sem write waiters killable. It focuses on the trivial ones which are taking the lock early after entering the syscall and they are not changing state before. Therefore it is very easy to change them to use down_write_killable and immediately return with -EINTR. This will allow the waiter to pass away without blocking the mmap_sem which might be required to make a forward progress. E.g. the oom reaper will need the lock for reading to dismantle the OOM victim address space. The only tricky function in this patch is vm_mmap_pgoff which has many call sites via vm_mmap. To reduce the risk keep vm_mmap with the original non-killable semantic for now. vm_munmap callers do not bother checking the return value so open code it into the munmap syscall path for now for simplicity. Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Mel Gorman <mgorman@suse.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Dave Hansen <dave.hansen@linux.intel.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>
2016-05-24mm: memcontrol: fix possible css ref leak on oomVladimir Davydov
mem_cgroup_oom may be invoked multiple times while a process is handling a page fault, in which case current->memcg_in_oom will be overwritten leaking the previously taken css reference. Link: http://lkml.kernel.org/r/1464019330-7579-1-git-send-email-vdavydov@virtuozzo.com Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Michal Hocko <mhocko@suse.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>
2016-05-23Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
Pull drm updates from Dave Airlie: "Here's the main drm pull request for 4.7, it's been a busy one, and I've been a bit more distracted in real life this merge window. Lots more ARM drivers, not sure if it'll ever end. I think I've at least one more coming the next merge window. But changes are all over the place, support for AMD Polaris GPUs is in here, some missing GM108 support for nouveau (found in some Lenovos), a bunch of MST and skylake fixes. I've also noticed a few fixes from Arnd in my inbox, that I'll try and get in asap, but I didn't think they should hold this up. New drivers: - Hisilicon kirin display driver - Mediatek MT8173 display driver - ARC PGU - bitstreamer on Synopsys ARC SDP boards - Allwinner A13 initial RGB output driver - Analogix driver for DisplayPort IP found in exynos and rockchip DRM Core: - UAPI headers fixes and C++ safety - DRM connector reference counting - DisplayID mode parsing for Dell 5K monitors - Removal of struct_mutex from drivers - Connector registration cleanups - MST robustness fixes - MAINTAINERS updates - Lockless GEM object freeing - Generic fbdev deferred IO support panel: - Support for a bunch of new panels i915: - VBT refactoring - PLL computation cleanups - DSI support for BXT - Color manager support - More atomic patches - GEM improvements - GuC fw loading fixes - DP detection fixes - SKL GPU hang fixes - Lots of BXT fixes radeon/amdgpu: - Initial Polaris support - GPUVM/Scheduler/Clock/Power improvements - ASYNC pageflip support - New mesa feature support nouveau: - GM108 support - Power sensor support improvements - GR init + ucode fixes. - Use GPU provided topology information vmwgfx: - Add host messaging support gma500: - Some cleanups and fixes atmel: - Bridge support - Async atomic commit support fsl-dcu: - Timing controller for LCD support - Pixel clock polarity support rcar-du: - Misc fixes exynos: - Pipeline clock support - Exynoss4533 SoC support - HW trigger mode support - export HDMI_PHY clock - DECON5433 fixes - Use generic prime functions - use DMA mapping APIs rockchip: - Lots of little fixes vc4: - Render node support - Gamma ramp support - DPI output support msm: - Mostly cleanups and fixes - Conversion to generic struct fence etnaviv: - Fix for prime buffer handling - Allow hangcheck to be coalesced with other wakeups tegra: - Gamme table size fix" * 'drm-next' of git://people.freedesktop.org/~airlied/linux: (1050 commits) drm/edid: add displayid detailed 1 timings to the modelist. (v1.1) drm/edid: move displayid validation to it's own function. drm/displayid: Iterate over all DisplayID blocks drm/edid: move displayid tiled block parsing into separate function. drm: Nuke ->vblank_disable_allowed drm/vmwgfx: Report vmwgfx version to vmware.log drm/vmwgfx: Add VMWare host messaging capability drm/vmwgfx: Kill some lockdep warnings drm/nouveau/gr/gf100-: fix race condition in fecs/gpccs ucode drm/nouveau/core: recognise GM108 chipsets drm/nouveau/gr/gm107-: fix touching non-existent ppcs in attrib cb setup drm/nouveau/gr/gk104-: share implementation of ppc exception init drm/nouveau/gr/gk104-: move rop_active_fbps init to nonctx drm/nouveau/bios/pll: check BIT table version before trying to parse it drm/nouveau/bios/pll: prevent oops when limits table can't be parsed drm/nouveau/volt/gk104: round up in gk104_volt_set drm/nouveau/fb/gm200: setup mmu debug buffer registers at init() drm/nouveau/fb/gk20a,gm20b: setup mmu debug buffer registers at init() drm/nouveau/fb/gf100-: allocate mmu debug buffers drm/nouveau/fb: allow chipset-specific actions for oneinit() ...
2016-05-23Merge tag 'libnvdimm-for-4.7' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this update was stabilized before the merge window and appeared in -next. The "device dax" implementation was revised this week in response to review feedback, and to address failures detected by the recently expanded ndctl unit test suite. Not included in this pull request are two dax topic branches (dax error handling, and dax radix-tree locking). These topics were deferred to get a few more days of -next integration testing, and to coordinate a branch baseline with Ted and the ext4 tree. Vishal and Ross will send the error handling and locking topics respectively in the next few days. This branch has received a positive build result from the kbuild robot across 226 configs. Summary: - Device DAX for persistent memory: Device DAX is the device-centric analogue of Filesystem DAX (CONFIG_FS_DAX). It allows memory ranges to be allocated and mapped without need of an intervening file system. Device DAX is strict, precise and predictable. Specifically this interface: a) Guarantees fault granularity with respect to a given page size (pte, pmd, or pud) set at configuration time. b) Enforces deterministic behavior by being strict about what fault scenarios are supported. Persistent memory is the first target, but the mechanism is also targeted for exclusive allocations of performance/feature differentiated memory ranges. - Support for the HPE DSM (device specific method) command formats. This enables management of these first generation devices until a unified DSM specification materializes. - Further ACPI 6.1 compliance with support for the common dimm identifier format. - Various fixes and cleanups across the subsystem" * tag 'libnvdimm-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (40 commits) libnvdimm, dax: fix deletion libnvdimm, dax: fix alignment validation libnvdimm, dax: autodetect support libnvdimm: release ida resources Revert "block: enable dax for raw block devices" /dev/dax, core: file operations and dax-mmap /dev/dax, pmem: direct access to persistent memory libnvdimm: stop requiring a driver ->remove() method libnvdimm, dax: record the specified alignment of a dax-device instance libnvdimm, dax: reserve space to store labels for device-dax libnvdimm, dax: introduce device-dax infrastructure nfit: add sysfs dimm 'family' and 'dsm_mask' attributes tools/testing/nvdimm: ND_CMD_CALL support nfit: disable vendor specific commands nfit: export subsystem ids as attributes nfit: fix format interface code byte order per ACPI6.1 nfit, libnvdimm: limited/whitelisted dimm command marshaling mechanism nfit, libnvdimm: clarify "commands" vs "_DSMs" libnvdimm: increase max envelope size for ioctl acpi/nfit: Add sysfs "id" for NVDIMM ID ...
2016-05-23x86: remove more uaccess_32.h complexityLinus Torvalds
I'm looking at trying to possibly merge the 32-bit and 64-bit versions of the x86 uaccess.h implementation, but first this needs to be cleaned up. For example, the 32-bit version of "__copy_from_user_inatomic()" is mostly the special cases for the constant size, and it's actually almost never relevant. Most users aren't actually using a constant size anyway, and the few cases that do small constant copies are better off just using __get_user() instead. So get rid of the unnecessary complexity. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21/dev/dax, core: file operations and dax-mmapDan Williams
The "Device DAX" core enables dax mappings of performance / feature differentiated memory. An open mapping or file handle keeps the backing struct device live, but new mappings are only possible while the device is enabled. Faults are handled under rcu_read_lock to synchronize with the enabled state of the device. Similar to the filesystem-dax case the backing memory may optionally have struct page entries. However, unlike fs-dax there is no support for private mappings, or mappings that are not backed by media (see use of zero-page in fs-dax). Mappings are always guaranteed to match the alignment of the dax_region. If the dax_region is configured to have a 2MB alignment, all mappings are guaranteed to be backed by a pmd entry. Contrast this determinism with the fs-dax case where pmd mappings are opportunistic. If userspace attempts to force a misaligned mapping, the driver will fail the mmap attempt. See dax_dev_check_vma() for other scenarios that are rejected, like MAP_PRIVATE mappings. Cc: Hannes Reinecke <hare@suse.de> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2016-05-21radix-tree: introduce radix_tree_replace_clear_tags()Matthew Wilcox
In addition to replacing the entry, we also clear all associated tags. This is really a one-off special for page_cache_tree_delete() which had far too much detailed knowledge about how the radix tree works. For efficiency, factor node_tag_clear() out of radix_tree_tag_clear() It can be used by radix_tree_delete_item() as well as radix_tree_replace_clear_tags(). Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Jan Kara <jack@suse.com> Cc: Neil Brown <neilb@suse.de> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21raxix-tree: introduce CONFIG_RADIX_TREE_MULTIORDERMatthew Wilcox
I've been receiving increasingly concerned notes from 0day about how much my recent changes have been bloating the radix tree. Make it happier by only including multiorder support if CONFIG_TRANSPARENT_HUGEPAGES is set. This is an independent Kconfig option, so other radix tree users can also set it if they have a need. Signed-off-by: Matthew Wilcox <willy@linux.intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kirill Shutemov <kirill.shutemov@linux.intel.com> Cc: Jan Kara <jack@suse.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21mm/zsmalloc: don't fail if can't create debugfs infoDan Streetman
Change the return type of zs_pool_stat_create() to void, and remove the logic to abort pool creation if the stat debugfs dir/file could not be created. The debugfs stat file is for debugging/information only, and doesn't affect operation of zsmalloc; there is no reason to abort creating the pool if the stat file can't be created. This was seen with zswap, which used the same name for all pool creations, which caused zsmalloc to fail to create a second pool for zswap if CONFIG_ZSMALLOC_STAT was enabled. Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Dan Streetman <dan.streetman@canonical.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>
2016-05-21mm/zswap: use workqueue to destroy poolDan Streetman
Add a work_struct to struct zswap_pool, and change __zswap_pool_empty to use the workqueue instead of using call_rcu(). When zswap destroys a pool no longer in use, it uses call_rcu() to perform the destruction/freeing. Since that executes in softirq context, it must not sleep. However, actually destroying the pool involves freeing the per-cpu compressors (which requires locking the cpu_add_remove_lock mutex) and freeing the zpool, for which the implementation may sleep (e.g. zsmalloc calls kmem_cache_destroy, which locks the slab_mutex). So if either mutex is currently taken, or any other part of the compressor or zpool implementation sleeps, it will result in a BUG(). It's not easy to reproduce this when changing zswap's params normally. In testing with a loaded system, this does not fail: $ cd /sys/module/zswap/parameters $ echo lz4 > compressor ; echo zsmalloc > zpool nor does this: $ while true ; do > echo lzo > compressor ; echo zbud > zpool > sleep 1 > echo lz4 > compressor ; echo zsmalloc > zpool > sleep 1 > done although it's still possible either of those might fail, depending on whether anything else besides zswap has locked the mutexes. However, changing a parameter with no delay immediately causes the schedule while atomic BUG: $ while true ; do > echo lzo > compressor ; echo lz4 > compressor > done This is essentially the same as Yu Zhao's proposed patch to zsmalloc, but moved to zswap, to cover compressor and zpool freeing. Fixes: f1c54846ee45 ("zswap: dynamic pool creation") Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reported-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21zsmalloc: require GFP in zs_malloc()Sergey Senozhatsky
Pass GFP flags to zs_malloc() instead of using a fixed mask supplied to zs_create_pool(), so we can be more flexible, but, more importantly, we need this to switch zram to per-cpu compression streams -- zram will try to allocate handle with preemption disabled in a fast path and switch to a slow path (using different gfp mask) if the fast one has failed. Apart from that, this also align zs_malloc() interface with zspool/zbud. [sergey.senozhatsky@gmail.com: pass GFP flags to zs_malloc() instead of using a fixed mask] Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Link: http://lkml.kernel.org/r/20160429150942.GA637@swordfish Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21zsmalloc: remove unused pool param in obj_freeMinchan Kim
Let's remove unused pool param in obj_free Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21zsmalloc: reorder function parametersMinchan Kim
Clean up function parameter ordering to order higher data structure first. Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21zsmalloc: clean up many BUG_ONMinchan Kim
There are many BUG_ON in zsmalloc.c which is not recommened so change them as alternatives. Normal rule is as follows: 1. avoid BUG_ON if possible. Instead, use VM_BUG_ON or VM_BUG_ON_PAGE 2. use VM_BUG_ON_PAGE if we need to see struct page's fields 3. use those assertion in primitive functions so higher functions can rely on the assertion in the primitive function. 4. Don't use assertion if following instruction can trigger Oops Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21zsmalloc: use first_page rather than pageMinchan Kim
Clean up function parameter "struct page". Many functions of zsmalloc expect that page paramter is "first_page" so use "first_page" rather than "page" for code readability. Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21mm/kasan: add API to check memory regionsAndrey Ryabinin
Memory access coded in an assembly won't be seen by KASAN as a compiler can instrument only C code. Add kasan_check_[read,write]() API which is going to be used to check a certain memory range. Link: http://lkml.kernel.org/r/1462538722-1574-3-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21mm/kasan: print name of mem[set,cpy,move]() caller in reportAndrey Ryabinin
When bogus memory access happens in mem[set,cpy,move]() it's usually caller's fault. So don't blame mem[set,cpy,move]() in bug report, blame the caller instead. Before: BUG: KASAN: out-of-bounds access in memset+0x23/0x40 at <address> After: BUG: KASAN: out-of-bounds access in <memset_caller> at <address> Link: http://lkml.kernel.org/r/1462538722-1574-2-git-send-email-aryabinin@virtuozzo.com Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Acked-by: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21mm, kasan: don't call kasan_krealloc() from ksize().Alexander Potapenko
Instead of calling kasan_krealloc(), which replaces the memory allocation stack ID (if stack depot is used), just unpoison the whole memory chunk. Signed-off-by: Alexander Potapenko <glider@google.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Konstantin Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-21mm: kasan: initial memory quarantine implementationAlexander Potapenko
Quarantine isolates freed objects in a separate queue. The objects are returned to the allocator later, which helps to detect use-after-free errors. When the object is freed, its state changes from KASAN_STATE_ALLOC to KASAN_STATE_QUARANTINE. The object is poisoned and put into quarantine instead of being returned to the allocator, therefore every subsequent access to that object triggers a KASAN error, and the error handler is able to say where the object has been allocated and deallocated. When it's time for the object to leave quarantine, its state becomes KASAN_STATE_FREE and it's returned to the allocator. From now on the allocator may reuse it for another allocation. Before that happens, it's still possible to detect a use-after free on that object (it retains the allocation/deallocation stacks). When the allocator reuses this object, the shadow is unpoisoned and old allocation/deallocation stacks are wiped. Therefore a use of this object, even an incorrect one, won't trigger ASan warning. Without the quarantine, it's not guaranteed that the objects aren't reused immediately, that's why the probability of catching a use-after-free is lower than with quarantine in place. Quarantine isolates freed objects in a separate queue. The objects are returned to the allocator later, which helps to detect use-after-free errors. Freed objects are first added to per-cpu quarantine queues. When a cache is destroyed or memory shrinking is requested, the objects are moved into the global quarantine queue. Whenever a kmalloc call allows memory reclaiming, the oldest objects are popped out of the global queue until the total size of objects in quarantine is less than 3/4 of the maximum quarantine size (which is a fraction of installed physical memory). As long as an object remains in the quarantine, KASAN is able to report accesses to it, so the chance of reporting a use-after-free is increased. Once the object leaves quarantine, the allocator may reuse it, in which case the object is unpoisoned and KASAN can't detect incorrect accesses to it. Right now quarantine support is only enabled in SLAB allocator. Unification of KASAN features in SLAB and SLUB will be done later. This patch is based on the "mm: kasan: quarantine" patch originally prepared by Dmitry Chernenkov. A number of improvements have been suggested by Andrey Ryabinin. [glider@google.com: v9] Link: http://lkml.kernel.org/r/1462987130-144092-1-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Konstantin Serebryany <kcc@google.com> Cc: Dmitry Chernenkov <dmitryc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>