- Jul 17, 2019
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Henry Burns authored
z3fold_page_migration() calls memcpy(new_zhdr, zhdr, PAGE_SIZE). However, zhdr contains fields that can't be directly coppied over (ex: list_head, a circular linked list). We only need to initialize the linked lists in new_zhdr, as z3fold_isolate_page() already ensures that these lists are empty Additionally it is possible that zhdr->work has been placed in a workqueue. In this case we shouldn't migrate the page, as zhdr->work references zhdr as opposed to new_zhdr. Link: http://lkml.kernel.org/r/20190716000520.230595-1-henryburns@google.com Fixes: 1f862989 ("mm/z3fold.c: support page migration") Signed-off-by:
Henry Burns <henryburns@google.com> Reviewed-by:
Shakeel Butt <shakeelb@google.com> Cc: Vitaly Vul <vitaly.vul@sony.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Jonathan Adams <jwadams@google.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Henry Burns authored
z3fold_page_migrate() will never succeed because it attempts to acquire a lock that has already been taken by migrate.c in __unmap_and_move(). __unmap_and_move() migrate.c trylock_page(oldpage) move_to_new_page(oldpage_newpage) a_ops->migrate_page(oldpage, newpage) z3fold_page_migrate(oldpage, newpage) trylock_page(oldpage) Link: http://lkml.kernel.org/r/20190710213238.91835-1-henryburns@google.com Fixes: 1f862989 ("mm/z3fold.c: support page migration") Signed-off-by: -
Andrew Morton authored
Six sites are presently altering current->reclaim_state. There is a risk that one function stomps on a caller's value. Use a helper function to catch such errors. Cc: Yafang Shao <laoar.shao@gmail.com> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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Yafang Shao authored
There are six different reclaim paths by now: - kswapd reclaim path - node reclaim path - hibernate preallocate memory reclaim path - direct reclaim path - memcg reclaim path - memcg softlimit reclaim path The slab caches reclaimed in these paths are only calculated in the above three paths. There're some drawbacks if we don't calculate the reclaimed slab caches. - The sc->nr_reclaimed isn't correct if there're some slab caches relcaimed in this path. - The slab caches may be reclaimed thoroughly if there're lots of reclaimable slab caches and few page caches. Let's take an easy example for this case. If one memcg is full of slab caches and the limit of it is 512M, in other words there're approximately 512M slab caches in this memcg. Then the limit of the memcg is reached and the memcg reclaim begins, and then in this memcg reclaim path it will continuesly reclaim the slab caches until the sc->priority drops to 0. After this reclaim stops, you will find there're few slab caches left, which is less than 20M in my test case. While after this patch applied the number is greater than 300M and the sc->priority only drops to 3. Link: http://lkml.kernel.org/r/1561112086-6169-3-git-send-email-laoar.shao@gmail.com Signed-off-by:
Yafang Shao <laoar.shao@gmail.com> Reviewed-by:
Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by:
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Yafang Shao authored
Patch series "mm/vmscan: calculate reclaimed slab in all reclaim paths". This patchset is to fix the issues in doing shrink slab. There're six different reclaim paths by now, - kswapd reclaim path - node reclaim path - hibernate preallocate memory reclaim path - direct reclaim path - memcg reclaim path - memcg softlimit reclaim path The slab caches reclaimed in these paths are only calculated in the above three paths. The issues are detailed explained in patch #2. We should calculate the reclaimed slab caches in every reclaim path. In order to do it, the struct reclaim_state is placed into the struct shrink_control. In node reclaim path, there'is another issue about shrinking slab, which is adressed in "mm/vmscan: shrink slab in node reclaim" (https://lore.kernel.org/linux-mm/1559874946-22960-1-git-send-email-laoar.shao@gmail.com/). This patch (of 2): The struct reclaim_state is used to record how many slab caches are reclaimed in one reclaim path. The struct shrink_control is used to control one reclaim path. So we'd better put reclaim_state into shrink_control. [laoar.shao@gmail.com: remove reclaim_state assignment from __perform_reclaim()] Link: http://lkml.kernel.org/r/1561381582-13697-1-git-send-email-laoar.shao@gmail.com Link: http://lkml.kernel.org/r/1561112086-6169-2-git-send-email-laoar.shao@gmail.com Signed-off-by:
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Yafang Shao authored
After commit 815744d7 ("mm: memcontrol: don't batch updates of local VM stats and events"), the local VM counter are not in sync with the hierarchical ones. Below is one example in a leaf memcg on my server (with 8 CPUs): inactive_file 3567570944 total_inactive_file 3568029696 We find that the deviation is very great because the 'val' in __mod_memcg_state() is in pages while the effective value in memcg_stat_show() is in bytes. So the maximum of this deviation between local VM stats and total VM stats can be (32 * number_of_cpu * PAGE_SIZE), that may be an unacceptably great value. We should keep the local VM stats in sync with the total stats. In order to keep this behavior the same across counters, this patch updates __mod_lruvec_state() and __count_memcg_events() as well. Link: http://lkml.kernel.org/r/1562851979-10610-1-git-send-email-laoar.shao@gmail.com Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yafang Shao <shaoyafang@didiglobal.com> Signed-off-by:
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Henry Burns authored
One of the gfp flags used to show that a page is movable is __GFP_HIGHMEM. Currently z3fold_alloc() fails when __GFP_HIGHMEM is passed. Now that z3fold pages are movable, we allow __GFP_HIGHMEM. We strip the movability related flags from the call to kmem_cache_alloc() for our slots since it is a kernel allocation. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20190712222118.108192-1-henryburns@google.com Signed-off-by:
Vitaly Wool <vitalywool@gmail.com> Reviewed-by:
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Ryohei Suzuki authored
A comment referred to a non-existent function alloc_cma(), which should have been cma_alloc(). Link: http://lkml.kernel.org/r/20190712085549.5920-1-ryh.szk.cmnty@gmail.com Signed-off-by:
Ryohei Suzuki <ryh.szk.cmnty@gmail.com> Reviewed-by:
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Arnd Bergmann authored
Clang gets rather confused about two variables in the same special section when one of them is not initialized, leading to an assembler warning later: /tmp/slab_common-18f869.s: Assembler messages: /tmp/slab_common-18f869.s:7526: Warning: ignoring changed section attributes for .data..ro_after_init Adding an initialization to kmalloc_caches is rather silly here but does avoid the issue. Link: https://bugs.llvm.org/show_bug.cgi?id=42570 Link: http://lkml.kernel.org/r/20190712090455.266021-1-arnd@arndb.de Signed-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
David Rientjes <rientjes@google.com> Reviewed-by:
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Arnd Bergmann authored
When CONFIG_SYSFS is disabled but CONFIG_TMPFS is enabled, we get a warning about shmem_parse_huge() never being called: mm/shmem.c:417:12: error: unused function 'shmem_parse_huge' [-Werror,-Wunused-function] static int shmem_parse_huge(const char *str) Change the #ifdef so we no longer build this function in that configuration. Link: http://lkml.kernel.org/r/20190712091141.673355-1-arnd@arndb.de Fixes: 144df3b288c4 ("vfs: Convert ramfs, shmem, tmpfs, devtmpfs, rootfs to use the new mount API") Signed-off-by:
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Vitaly Wool authored
As reported by Henry Burns: Running z3fold stress testing with address sanitization showed zhdr->slots was being used after it was freed. z3fold_free(z3fold_pool, handle) free_handle(handle) kmem_cache_free(pool->c_handle, zhdr->slots) release_z3fold_page_locked_list(kref) __release_z3fold_page(zhdr, true) zhdr_to_pool(zhdr) slots_to_pool(zhdr->slots) *BOOM* To fix this, add pointer to the pool back to z3fold_header and modify zhdr_to_pool to return zhdr->pool. Link: http://lkml.kernel.org/r/20190708134808.e89f3bfadd9f6ffd7eff9ba9@gmail.com Fixes: 7c2b8baa ("mm/z3fold.c: add structure for buddy handles") Signed-off-by:
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- Jul 15, 2019
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git://people.freedesktop.org/~thomash/linuxDave Airlie authored
This reverts commit 031e610a, reversing changes made to 52d2d44e. The mm changes in there we premature and not fully ack or reviewed by core mm folks, I dropped the ball by merging them via this tree, so lets take em all back out. Signed-off-by:
Dave Airlie <airlied@redhat.com>
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Dave Airlie authored
This reverts commit 6dfc43d3. Going to revert the whole vmwwgfx pull. Signed-off-by:
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Dave Airlie authored
mm/pgtable: drop pgtable_t variable from pte_fn_t functions drops the token came in via the hmm tree, this caused lots of conflicts, but applying this cleanup patch should reduce it to something easier to handle. Just accept the token is unused at this point. Signed-off-by:
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- Jul 12, 2019
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Tetsuo Handa authored
Since commit bbbe4802 ("mm, oom: remove 'prefer children over parent' heuristic") removed the "%s: Kill process %d (%s) score %u or sacrifice child\n" line, oc->chosen_points is no longer used after select_bad_process(). Link: http://lkml.kernel.org/r/1560853435-15575-1-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> Cc: Shakeel Butt <shakeelb@google.com> Cc: Roman Gushchin <guro@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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Shakeel Butt authored
Commit ef08e3b4 ("[PATCH] cpusets: confine oom_killer to mem_exclusive cpuset") introduces a heuristic where a potential oom-killer victim is skipped if the intersection of the potential victim and the current (the process triggered the oom) is empty based on the reason that killing such victim most probably will not help the current allocating process. However the commit 7887a3da ("[PATCH] oom: cpuset hint") changed the heuristic to just decrease the oom_badness scores of such potential victim based on the reason that the cpuset of such processes might have changed and previously they may have allocated memory on mems where the current allocating process can allocate from. Unintentionally 7887a3da ("[PATCH] oom: cpuset hint") introduced a side effect as the oom_badness is also exposed to the user space through /proc/[pid]/oom_score, so, readers with different cpusets can read different oom_score of the same process. Later, commit 6cf86ac6 ("oom: filter tasks not sharing the same cpuset") fixed the side effect introduced by 7887a3da by moving the cpuset intersection back to only oom-killer context and out of oom_badness. However the combination of ab290adb ("oom: make oom_unkillable_task() helper function") and 26ebc984 ("oom: /proc/<pid>/oom_score treat kernel thread honestly") unintentionally brought back the cpuset intersection check into the oom_badness calculation function. Other than doing cpuset/mempolicy intersection from oom_badness, the memcg oom context is also doing cpuset/mempolicy intersection which is quite wrong and is caught by syzcaller with the following report: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 28426 Comm: syz-executor.5 Not tainted 5.2.0-rc3-next-20190607 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline] RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline] RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline] RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155 Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff RSP: 0018:ffff888000127490 EFLAGS: 00010a03 RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001 RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007 R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6 FS: 00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000607304 CR3: 000000009237e000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: oom_evaluate_task+0x49/0x520 mm/oom_kill.c:321 mem_cgroup_scan_tasks+0xcc/0x180 mm/memcontrol.c:1169 select_bad_process mm/oom_kill.c:374 [inline] out_of_memory mm/oom_kill.c:1088 [inline] out_of_memory+0x6b2/0x1280 mm/oom_kill.c:1035 mem_cgroup_out_of_memory+0x1ca/0x230 mm/memcontrol.c:1573 mem_cgroup_oom mm/memcontrol.c:1905 [inline] try_charge+0xfbe/0x1480 mm/memcontrol.c:2468 mem_cgroup_try_charge+0x24d/0x5e0 mm/memcontrol.c:6073 mem_cgroup_try_charge_delay+0x1f/0xa0 mm/memcontrol.c:6088 do_huge_pmd_wp_page_fallback+0x24f/0x1680 mm/huge_memory.c:1201 do_huge_pmd_wp_page+0x7fc/0x2160 mm/huge_memory.c:1359 wp_huge_pmd mm/memory.c:3793 [inline] __handle_mm_fault+0x164c/0x3eb0 mm/memory.c:4006 handle_mm_fault+0x3b7/0xa90 mm/memory.c:4053 do_user_addr_fault arch/x86/mm/fault.c:1455 [inline] __do_page_fault+0x5ef/0xda0 arch/x86/mm/fault.c:1521 do_page_fault+0x71/0x57d arch/x86/mm/fault.c:1552 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1156 RIP: 0033:0x400590 Code: 06 e9 49 01 00 00 48 8b 44 24 10 48 0b 44 24 28 75 1f 48 8b 14 24 48 8b 7c 24 20 be 04 00 00 00 e8 f5 56 00 00 48 8b 74 24 08 <89> 06 e9 1e 01 00 00 48 8b 44 24 08 48 8b 14 24 be 04 00 00 00 8b RSP: 002b:00007fff7bc49780 EFLAGS: 00010206 RAX: 0000000000000001 RBX: 0000000000760000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 000000002000cffc RDI: 0000000000000001 RBP: fffffffffffffffe R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000075 R11: 0000000000000246 R12: 0000000000760008 R13: 00000000004c55f2 R14: 0000000000000000 R15: 00007fff7bc499b0 Modules linked in: ---[ end trace a65689219582ffff ]--- RIP: 0010:__read_once_size include/linux/compiler.h:194 [inline] RIP: 0010:has_intersects_mems_allowed mm/oom_kill.c:84 [inline] RIP: 0010:oom_unkillable_task mm/oom_kill.c:168 [inline] RIP: 0010:oom_unkillable_task+0x180/0x400 mm/oom_kill.c:155 Code: c1 ea 03 80 3c 02 00 0f 85 80 02 00 00 4c 8b a3 10 07 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8d 74 24 10 4c 89 f2 48 c1 ea 03 <80> 3c 02 00 0f 85 67 02 00 00 49 8b 44 24 10 4c 8d a0 68 fa ff ff RSP: 0018:ffff888000127490 EFLAGS: 00010a03 RAX: dffffc0000000000 RBX: ffff8880a4cd5438 RCX: ffffffff818dae9c RDX: 100000000c3cc602 RSI: ffffffff818dac8d RDI: 0000000000000001 RBP: ffff8880001274d0 R08: ffff888000086180 R09: ffffed1015d26be0 R10: ffffed1015d26bdf R11: ffff8880ae935efb R12: 8000000061e63007 R13: 0000000000000000 R14: 8000000061e63017 R15: 1ffff11000024ea6 FS: 00005555561f5940(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f823000 CR3: 000000009237e000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 The fix is to decouple the cpuset/mempolicy intersection check from oom_unkillable_task() and make sure cpuset/mempolicy intersection check is only done in the global oom context. [shakeelb@google.com: change function name and update comment] Link: http://lkml.kernel.org/r/20190628152421.198994-3-shakeelb@google.com Link: http://lkml.kernel.org/r/20190624212631.87212-3-shakeelb@google.com Signed-off-by:
<syzbot+d0fc9d3c166bc5e4a94b@syzkaller.appspotmail.com> Acked-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Shakeel Butt authored
oom_unkillable_task() can be called from three different contexts i.e. global OOM, memcg OOM and oom_score procfs interface. At the moment oom_unkillable_task() does a task_in_mem_cgroup() check on the given process. Since there is no reason to perform task_in_mem_cgroup() check for global OOM and oom_score procfs interface, those contexts provide NULL memcg and skips the task_in_mem_cgroup() check. However for memcg OOM context, the oom_unkillable_task() is always called from mem_cgroup_scan_tasks() and thus task_in_mem_cgroup() check becomes redundant and effectively dead code. So, just remove the task_in_mem_cgroup() check altogether. Link: http://lkml.kernel.org/r/20190624212631.87212-2-shakeelb@google.com Signed-off-by:
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Shakeel Butt authored
dump_tasks() traverses all the existing processes even for the memcg OOM context which is not only unnecessary but also wasteful. This imposes a long RCU critical section even from a contained context which can be quite disruptive. Change dump_tasks() to be aligned with select_bad_process and use mem_cgroup_scan_tasks to selectively traverse only processes of the target memcg hierarchy during memcg OOM. Link: http://lkml.kernel.org/r/20190617231207.160865-1-shakeelb@google.com Signed-off-by:
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Tetsuo Handa authored
Since commit c03cd773 ("cgroup: Include dying leaders with live threads in PROCS iterations") corrected how CSS_TASK_ITER_PROCS works, mem_cgroup_scan_tasks() can use CSS_TASK_ITER_PROCS in order to check only one thread from each thread group. [penguin-kernel@I-love.SAKURA.ne.jp: remove thread group leader check in oom_evaluate_task()] Link: http://lkml.kernel.org/r/1560853257-14934-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Link: http://lkml.kernel.org/r/c763afc8-f0ae-756a-56a7-395f625b95fc@i-love.sakura.ne.jp Signed-off-by:
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Jane Chu authored
Some user who install SIGBUS handler that does longjmp out therefore keeping the process alive is confused by the error message "[188988.765862] Memory failure: 0x1840200: Killing cellsrv:33395 due to hardware memory corruption" Slightly modify the error message to improve clarity. Link: http://lkml.kernel.org/r/1558403523-22079-1-git-send-email-jane.chu@oracle.com Signed-off-by:
Jane Chu <jane.chu@oracle.com> Acked-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by:
Pankaj Gupta <pagupta@redhat.com> Reviewed-by:
Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by:
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Roman Gushchin authored
Vmalloc() is getting more and more used these days (kernel stacks, bpf and percpu allocator are new top users), and the total % of memory consumed by vmalloc() can be pretty significant and changes dynamically. /proc/meminfo is the best place to display this information: its top goal is to show top consumers of the memory. Since the VmallocUsed field in /proc/meminfo is not in use for quite a long time (it has been defined to 0 by a5ad88ce ("mm: get rid of 'vmalloc_info' from /proc/meminfo")), let's reuse it for showing the actual physical memory consumption of vmalloc(). Link: http://lkml.kernel.org/r/20190417194002.12369-3-guro@fb.com Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Reviewed-by:
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Konstantin Khlebnikov authored
This function is used by ptrace and proc files like /proc/pid/cmdline and /proc/pid/environ. Access_remote_vm never returns error codes, all errors are ignored and only size of successfully read data is returned. So, if current task was killed we'll simply return 0 (bytes read). Mmap_sem could be locked for a long time or forever if something goes wrong. Using a killable lock permits cleanup of stuck tasks and simplifies investigation. Link: http://lkml.kernel.org/r/156007494202.3335.16782303099589302087.stgit@buzz Signed-off-by:
Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by:
Michal Koutný <mkoutny@suse.com> Acked-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Yang Shi authored
Commit bd4c82c2 ("mm, THP, swap: delay splitting THP after swapped out"), THP can be swapped out in a whole. But, nr_reclaimed and some other vm counters still get inc'ed by one even though a whole THP (512 pages) gets swapped out. This doesn't make too much sense to memory reclaim. For example, direct reclaim may just need reclaim SWAP_CLUSTER_MAX pages, reclaiming one THP could fulfill it. But, if nr_reclaimed is not increased correctly, direct reclaim may just waste time to reclaim more pages, SWAP_CLUSTER_MAX * 512 pages in worst case. And, it may cause pgsteal_{kswapd|direct} is greater than pgscan_{kswapd|direct}, like the below: pgsteal_kswapd 122933 pgsteal_direct 26600225 pgscan_kswapd 174153 pgscan_direct 14678312 nr_reclaimed and nr_scanned must be fixed in parallel otherwise it would break some page reclaim logic, e.g. vmpressure: this looks at the scanned/reclaimed ratio so it won't change semantics as long as scanned & reclaimed are fixed in parallel. compaction/reclaim: compaction wants a certain number of physical pages freed up before going back to compacting. kswapd priority raising: kswapd raises priority if we scan fewer pages than the reclaim target (which itself is obviously expressed in order-0 pages). As a result, kswapd can falsely raise its aggressiveness even when it's making great progress. Other than nr_scanned and nr_reclaimed, some other counters, e.g. pgactivate, nr_skipped, nr_ref_keep and nr_unmap_fail need to be fixed too since they are user visible via cgroup, /proc/vmstat or trace points, otherwise they would be underreported. When isolating pages from LRUs, nr_taken has been accounted in base page, but nr_scanned and nr_skipped are still accounted in THP. It doesn't make too much sense too since this may cause trace point underreport the numbers as well. So accounting those counters in base page instead of accounting THP as one page. nr_dirty, nr_unqueued_dirty, nr_congested and nr_writeback are used by file cache, so they are not impacted by THP swap. This change may result in lower steal/scan ratio in some cases since THP may get split during page reclaim, then a part of tail pages get reclaimed instead of the whole 512 pages, but nr_scanned is accounted by 512, particularly for direct reclaim. But, this should be not a significant issue. Link: http://lkml.kernel.org/r/1559025859-72759-2-git-send-email-yang.shi@linux.alibaba.com Signed-off-by:
Yang Shi <yang.shi@linux.alibaba.com> Reviewed-by:
"Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Shakeel Butt <shakeelb@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Michal Hocko <mhocko@kernel.org> Signed-off-by:
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Yang Shi authored
Commit 9092c71b ("mm: use sc->priority for slab shrink targets") has broken up the relationship between sc->nr_scanned and slab pressure. The sc->nr_scanned can't double slab pressure anymore. So, it sounds no sense to still keep sc->nr_scanned inc'ed. Actually, it would prevent from adding pressure on slab shrink since excessive sc->nr_scanned would prevent from scan->priority raise. The bonnie test doesn't show this would change the behavior of slab shrinkers. w/ w/o /sec %CP /sec %CP Sequential delete: 3960.6 94.6 3997.6 96.2 Random delete: 2518 63.8 2561.6 64.6 The slight increase of "/sec" without the patch would be caused by the slight increase of CPU usage. Link: http://lkml.kernel.org/r/1559025859-72759-1-git-send-email-yang.shi@linux.alibaba.com Signed-off-by:
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Alexander Potapenko authored
Patch series "add init_on_alloc/init_on_free boot options", v10. Provide init_on_alloc and init_on_free boot options. These are aimed at preventing possible information leaks and making the control-flow bugs that depend on uninitialized values more deterministic. Enabling either of the options guarantees that the memory returned by the page allocator and SL[AU]B is initialized with zeroes. SLOB allocator isn't supported at the moment, as its emulation of kmem caches complicates handling of SLAB_TYPESAFE_BY_RCU caches correctly. Enabling init_on_free also guarantees that pages and heap objects are initialized right after they're freed, so it won't be possible to access stale data by using a dangling pointer. As suggested by Michal Hocko, right now we don't let the heap users to disable initialization for certain allocations. There's not enough evidence that doing so can speed up real-life cases, and introducing ways to opt-out may result in things going out of control. This patch (of 2): The new options are needed to prevent possible information leaks and make control-flow bugs that depend on uninitialized values more deterministic. This is expected to be on-by-default on Android and Chrome OS. And it gives the opportunity for anyone else to use it under distros too via the boot args. (The init_on_free feature is regularly requested by folks where memory forensics is included in their threat models.) init_on_alloc=1 makes the kernel initialize newly allocated pages and heap objects with zeroes. Initialization is done at allocation time at the places where checks for __GFP_ZERO are performed. init_on_free=1 makes the kernel initialize freed pages and heap objects with zeroes upon their deletion. This helps to ensure sensitive data doesn't leak via use-after-free accesses. Both init_on_alloc=1 and init_on_free=1 guarantee that the allocator returns zeroed memory. The two exceptions are slab caches with constructors and SLAB_TYPESAFE_BY_RCU flag. Those are never zero-initialized to preserve their semantics. Both init_on_alloc and init_on_free default to zero, but those defaults can be overridden with CONFIG_INIT_ON_ALLOC_DEFAULT_ON and CONFIG_INIT_ON_FREE_DEFAULT_ON. If either SLUB poisoning or page poisoning is enabled, those options take precedence over init_on_alloc and init_on_free: initialization is only applied to unpoisoned allocations. Slowdown for the new features compared to init_on_free=0, init_on_alloc=0: hackbench, init_on_free=1: +7.62% sys time (st.err 0.74%) hackbench, init_on_alloc=1: +7.75% sys time (st.err 2.14%) Linux build with -j12, init_on_free=1: +8.38% wall time (st.err 0.39%) Linux build with -j12, init_on_free=1: +24.42% sys time (st.err 0.52%) Linux build with -j12, init_on_alloc=1: -0.13% wall time (st.err 0.42%) Linux build with -j12, init_on_alloc=1: +0.57% sys time (st.err 0.40%) The slowdown for init_on_free=0, init_on_alloc=0 compared to the baseline is within the standard error. The new features are also going to pave the way for hardware memory tagging (e.g. arm64's MTE), which will require both on_alloc and on_free hooks to set the tags for heap objects. With MTE, tagging will have the same cost as memory initialization. Although init_on_free is rather costly, there are paranoid use-cases where in-memory data lifetime is desired to be minimized. There are various arguments for/against the realism of the associated threat models, but given that we'll need the infrastructure for MTE anyway, and there are people who want wipe-on-free behavior no matter what the performance cost, it seems reasonable to include it in this series. [glider@google.com: v8] Link: http://lkml.kernel.org/r/20190626121943.131390-2-glider@google.com [glider@google.com: v9] Link: http://lkml.kernel.org/r/20190627130316.254309-2-glider@google.com [glider@google.com: v10] Link: http://lkml.kernel.org/r/20190628093131.199499-2-glider@google.com Link: http://lkml.kernel.org/r/20190617151050.92663-2-glider@google.com Signed-off-by:
Alexander Potapenko <glider@google.com> Acked-by:
Kees Cook <keescook@chromium.org> Acked-by: Michal Hocko <mhocko@suse.cz> [page and dmapool parts Acked-by:
James Morris <jamorris@linux.microsoft.com>]> Cc: Christoph Lameter <cl@linux.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Sandeep Patil <sspatil@android.com> Cc: Laura Abbott <labbott@redhat.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Jann Horn <jannh@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Marco Elver <elver@google.com> Signed-off-by:
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Nicholas Piggin authored
CONFIG_NUMA on 64-bit CPUs currently enables hashdist unconditionally even when booting on single node machines. This causes the large system hashes to be allocated with vmalloc, and mapped with small pages. This change clears hashdist if only one node has come up with memory. This results in the important large inode and dentry hashes using memblock allocations. All others are within 4MB size up to about 128GB of RAM, which allows them to be allocated from the linear map on most non-NUMA images. Other big hashes like futex and TCP should eventually be moved over to the same style of allocation as those vfs caches that use HASH_EARLY if !hashdist, so they don't exceed MAX_ORDER on very large non-NUMA images. This brings dTLB misses for linux kernel tree `git diff` from ~45,000 to ~8,000 on a Kaby Lake KVM guest with 8MB dentry hash and mitigations=off (performance is in the noise, under 1% difference, page tables are likely to be well cached for this workload). Link: http://lkml.kernel.org/r/20190605144814.29319-2-npiggin@gmail.com Signed-off-by:
Nicholas Piggin <npiggin@gmail.com> Reviewed-by:
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Nicholas Piggin authored
The kernel currently clamps large system hashes to MAX_ORDER when hashdist is not set, which is rather arbitrary. vmalloc space is limited on 32-bit machines, but this shouldn't result in much more used because of small physical memory limiting system hash sizes. Include "vmalloc" or "linear" in the kernel log message. Link: http://lkml.kernel.org/r/20190605144814.29319-1-npiggin@gmail.com Signed-off-by:
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Geert Uytterhoeven authored
Link: http://lkml.kernel.org/r/20190607113509.15032-1-geert+renesas@glider.be Signed-off-by:
Geert Uytterhoeven <geert+renesas@glider.be> Reviewed-by:
Souptick Joarder <jrdr.linux@gmail.com> Signed-off-by:
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Uladzislau Rezki (Sony) authored
Trigger a warning if an object that is about to be freed is detached. We used to have a BUG_ON(), but even though it is considered as faulty behaviour that is not a good reason to break a system. Link: http://lkml.kernel.org/r/20190606120411.8298-5-urezki@gmail.com Signed-off-by:
Uladzislau Rezki (Sony) <urezki@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleksiy Avramchenko <oleksiy.avramchenko@sonymobile.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Uladzislau Rezki (Sony) authored
It does not make sense to try to "unlink" the node that is definitely not linked with a list nor tree. On the first merge step VA just points to the previously disconnected busy area. On the second step, check if the node has been merged and do "unlink" if so, because now it points to an object that must be linked. Link: http://lkml.kernel.org/r/20190606120411.8298-4-urezki@gmail.com Signed-off-by:
Hillf Danton <hdanton@sina.com> Reviewed-by:
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Uladzislau Rezki (Sony) authored
Refactor the NE_FIT_TYPE split case when it comes to an allocation of one extra object. We need it in order to build a remaining space. The preload is done per CPU in non-atomic context with GFP_KERNEL flags. More permissive parameters can be beneficial for systems which are suffer from high memory pressure or low memory condition. For example on my KVM system(4xCPUs, no swap, 256MB RAM) i can simulate the failure of page allocation with GFP_NOWAIT flags. Using "stress-ng" tool and starting N workers spinning on fork() and exit(), i can trigger below trace: <snip> [ 179.815161] stress-ng-fork: page allocation failure: order:0, mode:0x40800(GFP_NOWAIT|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0 [ 179.815168] CPU: 0 PID: 12612 Comm: stress-ng-fork Not tainted 5.2.0-rc3+ #1003 [ 179.815170] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014 [ 179.815171] Call Trace: [ 179.815178] dump_stack+0x5c/0x7b [ 179.815182] warn_alloc+0x108/0x190 [ 179.815187] __alloc_pages_slowpath+0xdc7/0xdf0 [ 179.815191] __alloc_pages_nodemask+0x2de/0x330 [ 179.815194] cache_grow_begin+0x77/0x420 [ 179.815197] fallback_alloc+0x161/0x200 [ 179.815200] kmem_cache_alloc+0x1c9/0x570 [ 179.815202] alloc_vmap_area+0x32c/0x990 [ 179.815206] __get_vm_area_node+0xb0/0x170 [ 179.815208] __vmalloc_node_range+0x6d/0x230 [ 179.815211] ? _do_fork+0xce/0x3d0 [ 179.815213] copy_process.part.46+0x850/0x1b90 [ 179.815215] ? _do_fork+0xce/0x3d0 [ 179.815219] _do_fork+0xce/0x3d0 [ 179.815226] ? __do_page_fault+0x2bf/0x4e0 [ 179.815229] do_syscall_64+0x55/0x130 [ 179.815231] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 179.815234] RIP: 0033:0x7fedec4c738b ... [ 179.815237] RSP: 002b:00007ffda469d730 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 [ 179.815239] RAX: ffffffffffffffda RBX: 00007ffda469d730 RCX: 00007fedec4c738b [ 179.815240] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 [ 179.815241] RBP: 00007ffda469d780 R08: 00007fededd6e300 R09: 00007ffda47f50a0 [ 179.815242] R10: 00007fededd6e5d0 R11: 0000000000000246 R12: 0000000000000000 [ 179.815243] R13: 0000000000000020 R14: 0000000000000000 R15: 0000000000000000 [ 179.815245] Mem-Info: [ 179.815249] active_anon:12686 inactive_anon:14760 isolated_anon:0 active_file:502 inactive_file:61 isolated_file:70 unevictable:2 dirty:0 writeback:0 unstable:0 slab_reclaimable:2380 slab_unreclaimable:7520 mapped:15069 shmem:14813 pagetables:10833 bounce:0 free:1922 free_pcp:229 free_cma:0 <snip> Link: http://lkml.kernel.org/r/20190606120411.8298-3-urezki@gmail.com Signed-off-by: -
Uladzislau Rezki (Sony) authored
Patch series "Some cleanups for the KVA/vmalloc", v5. This patch (of 4): Remove unused argument from the __alloc_vmap_area() function. Link: http://lkml.kernel.org/r/20190606120411.8298-2-urezki@gmail.com Signed-off-by:
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Jean-Philippe Brucker authored
Make mmu_notifier_register() safer by issuing a memory barrier before registering a new notifier. This fixes a theoretical bug on weakly ordered CPUs. For example, take this simplified use of notifiers by a driver: my_struct->mn.ops = &my_ops; /* (1) */ mmu_notifier_register(&my_struct->mn, mm) ... hlist_add_head(&mn->hlist, &mm->mmu_notifiers); /* (2) */ ... Once mmu_notifier_register() releases the mm locks, another thread can invalidate a range: mmu_notifier_invalidate_range() ... hlist_for_each_entry_rcu(mn, &mm->mmu_notifiers, hlist) { if (mn->ops->invalidate_range) The read side relies on the data dependency between mn and ops to ensure that the pointer is properly initialized. But the write side doesn't have any dependency between (1) and (2), so they could be reordered and the readers could dereference an invalid mn->ops. mmu_notifier_register() does take all the mm locks before adding to the hlist, but those have acquire semantics which isn't sufficient. By calling hlist_add_head_rcu() instead of hlist_add_head() we update the hlist using a store-release, ensuring that readers see prior initialization of my_struct. This situation is better illustated by litmus test MP+onceassign+derefonce. Link: http://lkml.kernel.org/r/20190502133532.24981-1-jean-philippe.brucker@arm.com Fixes: cddb8a5c ("mmu-notifiers: core") Signed-off-by:Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Cc: Jérôme Glisse <jglisse@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Miguel Ojeda authored
If the caller asks us for offset == num, we should already fail in the first check, i.e. the one testing for offsets beyond the object. At the moment, we are failing on the second test anyway, since count cannot be 0. Still, to agree with the comment of the first test, we should first test it there. Link: http://lkml.kernel.org/r/20190528193004.GA7744@gmail.com Signed-off-by:
Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Reviewed-by:
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Anshuman Khandual authored
Drop the pgtable_t variable from all implementation for pte_fn_t as none of them use it. apply_to_pte_range() should stop computing it as well. Should help us save some cycles. Link: http://lkml.kernel.org/r/1556803126-26596-1-git-send-email-anshuman.khandual@arm.com Signed-off-by:
Matthew Wilcox <willy@infradead.org> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <jglisse@redhat.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Signed-off-by:
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Guenter Roeck authored
Several mips builds generate the following build warning. mm/gup.c:1788:13: warning: 'undo_dev_pagemap' defined but not used The function is declared unconditionally but only called from behind various ifdefs. Mark it __maybe_unused. Link: http://lkml.kernel.org/r/1562072523-22311-1-git-send-email-linux@roeck-us.net Signed-off-by:
Guenter Roeck <linux@roeck-us.net> Reviewed-by:
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Andy Lutomirski authored
If we end up without a PGD or PUD entry backing the gate area, don't BUG -- just fail gracefully. It's not entirely implausible that this could happen some day on x86. It doesn't right now even with an execute-only emulated vsyscall page because the fixmap shares the PUD, but the core mm code shouldn't rely on that particular detail to avoid OOPSing. Link: http://lkml.kernel.org/r/a1d9f4efb75b9d464e59fd6af00104b21c58f6f7.1561610798.git.luto@kernel.org Signed-off-by:
Andy Lutomirski <luto@kernel.org> Reviewed-by:
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Pingfan Liu authored
Both hugetlb and thp locate on the same migration type of pageblock, since they are allocated from a free_list[]. Based on this fact, it is enough to check on a single subpage to decide the migration type of the whole huge page. By this way, it saves (2M/4K - 1) times loop for pmd_huge on x86, similar on other archs. Furthermore, when executing isolate_huge_page(), it avoid taking global hugetlb_lock many times, and meanless remove/add to the local link list cma_page_list. [akpm@linux-foundation.org: make `i' and `step' unsigned] Link: http://lkml.kernel.org/r/1561612545-28997-1-git-send-email-kernelfans@gmail.com Signed-off-by:
Pingfan Liu <kernelfans@gmail.com> Reviewed-by:
Ira Weiny <ira.weiny@intel.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: John Hubbard <jhubbard@nvidia.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Keith Busch <keith.busch@intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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Christoph Hellwig authored
All other get_user_page_fast cases mark the page referenced, so do this here as well. Link: http://lkml.kernel.org/r/20190625143715.1689-17-hch@lst.de Signed-off-by:
Christoph Hellwig <hch@lst.de> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: David Miller <davem@davemloft.net> Cc: James Hogan <jhogan@kernel.org> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Khalid Aziz <khalid.aziz@oracle.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paul Burton <paul.burton@mips.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Rich Felker <dalias@libc.org> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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Christoph Hellwig authored
This applies the overflow fixes from 8fde12ca ("mm: prevent get_user_pages() from overflowing page refcount") to the powerpc hugepd code and brings it back in sync with the other GUP cases. Link: http://lkml.kernel.org/r/20190625143715.1689-16-hch@lst.de Signed-off-by:
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