- 05 Apr, 2019 1 commit
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Yang Shi authored
commit a7f40cfe upstream. When MPOL_MF_STRICT was specified and an existing page was already on a node that does not follow the policy, mbind() should return -EIO. But commit 6f4576e3 ("mempolicy: apply page table walker on queue_pages_range()") broke the rule. And commit c8633798 ("mm: mempolicy: mbind and migrate_pages support thp migration") didn't return the correct value for THP mbind() too. If MPOL_MF_STRICT is set, ignore vma_migratable() to make sure it reaches queue_pages_to_pte_range() or queue_pages_pmd() to check if an existing page was already on a node that does not follow the policy. And, non-migratable vma may be used, return -EIO too if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL was specified. Tested with https://github.com/metan-ucw/ltp/blob/master/testcases/kernel/syscalls/mbind/mbind02.c [akpm@linux-foundation.org: tweak code comment] Link: http://lkml.kernel.org/r/1553020556-38583-1-git-send-email-yang.shi@linux.alibaba.com Fixes: 6f4576e3 ("mempolicy: apply page table walker on queue_pages_range()") Signed-off-by:
Yang Shi <yang.shi@linux.alibaba.com> Signed-off-by:
Oscar Salvador <osalvador@suse.de> Reported-by:
Cyril Hrubis <chrubis@suse.cz> Suggested-by:
Kirill A. Shutemov <kirill@shutemov.name> Acked-by:
Rafael Aquini <aquini@redhat.com> Reviewed-by:
David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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- 27 Feb, 2019 1 commit
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Ralph Campbell authored
commit 050c17f2 upstream. The system call, get_mempolicy() [1], passes an unsigned long *nodemask pointer and an unsigned long maxnode argument which specifies the length of the user's nodemask array in bits (which is rounded up). The manual page says that if the maxnode value is too small, get_mempolicy will return EINVAL but there is no system call to return this minimum value. To determine this value, some programs search /proc/<pid>/status for a line starting with "Mems_allowed:" and use the number of digits in the mask to determine the minimum value. A recent change to the way this line is formatted [2] causes these programs to compute a value less than MAX_NUMNODES so get_mempolicy() returns EINVAL. Change get_mempolicy(), the older compat version of get_mempolicy(), and the copy_nodes_to_user() function to use nr_node_ids instead of MAX_NUMNODES, thus preserving the defacto method of computing the minimum size for the nodemask array and the maxnode argument. [1] http://man7.org/linux/man-pages/man2/get_mempolicy.2.html [2] https://lore.kernel.org/lkml/1545405631-6808-1-git-send-email-longman@redhat.com Link: http://lkml.kernel.org/r/20190211180245.22295-1-rcampbell@nvidia.com Fixes: 4fb8e5b89bcbbbb ("include/linux/nodemask.h: use nr_node_ids (not MAX_NUMNODES) in __nodemask_pr_numnodes()") Signed-off-by:
Ralph Campbell <rcampbell@nvidia.com> Suggested-by:
Alexander Duyck <alexander.duyck@gmail.com> Cc: Waiman Long <longman@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by:
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- 21 Nov, 2018 1 commit
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Andrea Arcangeli authored
commit ac5b2c18 upstream. THP allocation might be really disruptive when allocated on NUMA system with the local node full or hard to reclaim. Stefan has posted an allocation stall report on 4.12 based SLES kernel which suggests the same issue: kvm: page allocation stalls for 194572ms, order:9, mode:0x4740ca(__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_THISNODE|__GFP_MOVABLE|__GFP_DIRECT_RECLAIM), nodemask=(null) kvm cpuset=/ mems_allowed=0-1 CPU: 10 PID: 84752 Comm: kvm Tainted: G W 4.12.0+98-ph <a href="/view.php?id=1" title="[geschlossen] Integration Ramdisk" class="resolved">0000001</a> SLE15 (unreleased) Hardware name: Supermicro SYS-1029P-WTRT/X11DDW-NT, BIOS 2.0 12/05/2017 Call Trace: dump_stack+0x5c/0x84 warn_alloc+0xe0/0x180 __alloc_pages_slowpath+0x820/0xc90 __alloc_pages_nodemask+0x1cc/0x210 alloc_pages_vma+0x1e5/0x280 do_huge_pmd_wp_page+0x83f/0xf00 __handle_mm_fault+0x93d/0x1060 handle_mm_fault+0xc6/0x1b0 __do_page_fault+0x230/0x430 do_page_fault+0x2a/0x70 page_fault+0x7b/0x80 [...] Mem-Info: active_anon:126315487 inactive_anon:1612476 isolated_anon:5 active_file:60183 inactive_file:245285 isolated_file:0 unevictable:15657 dirty:286 writeback:1 unstable:0 slab_reclaimable:75543 slab_unreclaimable:2509111 mapped:81814 shmem:31764 pagetables:370616 bounce:0 free:32294031 free_pcp:6233 free_cma:0 Node 0 active_anon:254680388kB inactive_anon:1112760kB active_file:240648kB inactive_file:981168kB unevictable:13368kB isolated(anon):0kB isolated(file):0kB mapped:280240kB dirty:1144kB writeback:0kB shmem:95832kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 81225728kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no Node 1 active_anon:250583072kB inactive_anon:5337144kB active_file:84kB inactive_file:0kB unevictable:49260kB isolated(anon):20kB isolated(file):0kB mapped:47016kB dirty:0kB writeback:4kB shmem:31224kB shmem_thp: 0kB shmem_pmdmapped: 0kB anon_thp: 31897600kB writeback_tmp:0kB unstable:0kB all_unreclaimable? no The defrag mode is "madvise" and from the above report it is clear that the THP has been allocated for MADV_HUGEPAGA vma. Andrea has identified that the main source of the problem is __GFP_THISNODE usage: : The problem is that direct compaction combined with the NUMA : __GFP_THISNODE logic in mempolicy.c is telling reclaim to swap very : hard the local node, instead of failing the allocation if there's no : THP available in the local node. : : Such logic was ok until __GFP_THISNODE was added to the THP allocation : path even with MPOL_DEFAULT. : : The idea behind the __GFP_THISNODE addition, is that it is better to : provide local memory in PAGE_SIZE units than to use remote NUMA THP : backed memory. That largely depends on the remote latency though, on : threadrippers for example the overhead is relatively low in my : experience. : : The combination of __GFP_THISNODE and __GFP_DIRECT_RECLAIM results in : extremely slow qemu startup with vfio, if the VM is larger than the : size of one host NUMA node. This is because it will try very hard to : unsuccessfully swapout get_user_pages pinned pages as result of the : __GFP_THISNODE being set, instead of falling back to PAGE_SIZE : allocations and instead of trying to allocate THP on other nodes (it : would be even worse without vfio type1 GUP pins of course, except it'd : be swapping heavily instead). Fix this by removing __GFP_THISNODE for THP requests which are requesting the direct reclaim. This effectivelly reverts 5265047a on the grounds that the zone/node reclaim was known to be disruptive due to premature reclaim when there was memory free. While it made sense at the time for HPC workloads without NUMA awareness on rare machines, it was ultimately harmful in the majority of cases. The existing behaviour is similar, if not as widespare as it applies to a corner case but crucially, it cannot be tuned around like zone_reclaim_mode can. The default behaviour should always be to cause the least harm for the common case. If there are specialised use cases out there that want zone_reclaim_mode in specific cases, then it can be built on top. Longterm we should consider a memory policy which allows for the node reclaim like behavior for the specific memory ranges which would allow a [1] http://lkml.kernel.org/r/20180820032204.9591-1-aarcange@redhat.com Mel said: : Both patches look correct to me but I'm responding to this one because : it's the fix. The change makes sense and moves further away from the : severe stalling behaviour we used to see with both THP and zone reclaim : mode. : : I put together a basic experiment with usemem configured to reference a : buffer multiple times that is 80% the size of main memory on a 2-socket : box with symmetric node sizes and defrag set to "always". The defrag : setting is not the default but it would be functionally similar to : accessing a buffer with madvise(MADV_HUGEPAGE). Usemem is configured to : reference the buffer multiple times and while it's not an interesting : workload, it would be expected to complete reasonably quickly as it fits : within memory. The results were; : : usemem : vanilla noreclaim-v1 : Amean Elapsd-1 42.78 ( 0.00%) 26.87 ( 37.18%) : Amean Elapsd-3 27.55 ( 0.00%) 7.44 ( 73.00%) : Amean Elapsd-4 5.72 ( 0.00%) 5.69 ( 0.45%) : : This shows the elapsed time in seconds for 1 thread, 3 threads and 4 : threads referencing buffers 80% the size of memory. With the patches : applied, it's 37.18% faster for the single thread and 73% faster with two : threads. Note that 4 threads showing little difference does not indicate : the problem is related to thread counts. It's simply the case that 4 : threads gets spread so their workload mostly fits in one node. : : The overall view from /proc/vmstats is more startling : : 4.19.0-rc1 4.19.0-rc1 : vanillanoreclaim-v1r1 : Minor Faults 35593425 708164 : Major Faults 484088 36 : Swap Ins 3772837 0 : Swap Outs 3932295 0 : : Massive amounts of swap in/out without the patch : : Direct pages scanned 6013214 0 : Kswapd pages scanned 0 0 : Kswapd pages reclaimed 0 0 : Direct pages reclaimed 4033009 0 : : Lots of reclaim activity without the patch : : Kswapd efficiency 100% 100% : Kswapd velocity 0.000 0.000 : Direct efficiency 67% 100% : Direct velocity 11191.956 0.000 : : Mostly from direct reclaim context as you'd expect without the patch. : : Page writes by reclaim 3932314.000 0.000 : Page writes file 19 0 : Page writes anon 3932295 0 : Page reclaim immediate 42336 0 : : Writes from reclaim context is never good but the patch eliminates it. : : We should never have default behaviour to thrash the system for such a : basic workload. If zone reclaim mode behaviour is ever desired but on a : single task instead of a global basis then the sensible option is to build : a mempolicy that enforces that behaviour. This was a severe regression compared to previous kernels that made important workloads unusable and it starts when __GFP_THISNODE was added to THP allocations under MADV_HUGEPAGE. It is not a significant risk to go to the previous behavior before __GFP_THISNODE was added, it worked like that for years. This was simply an optimization to some lucky workloads that can fit in a single node, but it ended up breaking the VM for others that can't possibly fit in a single node, so going back is safe. [mhocko@suse.com: rewrote the changelog based on the one from Andrea] Link: http://lkml.kernel.org/r/20180925120326.24392-2-mhocko@kernel.org Fixes: 5265047a ("mm, thp: really limit transparent hugepage allocation to local node") Signed-off-by:
Andrea Arcangeli <aarcange@redhat.com> Signed-off-by:
Michal Hocko <mhocko@suse.com> Reported-by:
Stefan Priebe <s.priebe@profihost.ag> Debugged-by:
Alex Williamson <alex.williamson@redhat.com> Reviewed-by:
Mel Gorman <mgorman@techsingularity.net> Tested-by:
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- 30 May, 2018 3 commits
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Yisheng Xie authored
[ Upstream commit 8970a63e ] Alexander reported a use of uninitialized memory in __mpol_equal(), which is caused by incorrect use of preferred_node. When mempolicy in mode MPOL_PREFERRED with flags MPOL_F_LOCAL, it uses numa_node_id() instead of preferred_node, however, __mpol_equal() uses preferred_node without checking whether it is MPOL_F_LOCAL or not. [akpm@linux-foundation.org: slight comment tweak] Link: http://lkml.kernel.org/r/4ebee1c2-57f6-bcb8-0e2d-1833d1ee0bb7@huawei.com Fixes: fc36b8d3 ("mempolicy: use MPOL_F_LOCAL to Indicate Preferred Local Policy") Signed-off-by:
Yisheng Xie <xieyisheng1@huawei.com> Reported-by:
Alexander Potapenko <glider@google.com> Tested-by:
Sasha Levin <alexander.levin@microsoft.com> Signed-off-by:
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Yisheng Xie authored
[ Upstream commit 0486a38b ] As in manpage of migrate_pages, the errno should be set to EINVAL when none of the node IDs specified by new_nodes are on-line and allowed by the process's current cpuset context, or none of the specified nodes contain memory. However, when test by following case: new_nodes = 0; old_nodes = 0xf; ret = migrate_pages(pid, old_nodes, new_nodes, MAX); The ret will be 0 and no errno is set. As the new_nodes is empty, we should expect EINVAL as documented. To fix the case like above, this patch check whether target nodes AND current task_nodes is empty, and then check whether AND node_states[N_MEMORY] is empty. Link: http://lkml.kernel.org/r/1510882624-44342-4-git-send-email-xieyisheng1@huawei.com Signed-off-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Chris Salls <salls@cs.ucsb.edu> Cc: Christopher Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Tan Xiaojun <tanxiaojun@huawei.com> Signed-off-by:
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Yisheng Xie authored
[ Upstream commit 56521e7a ] As Xiaojun reported the ltp of migrate_pages01 will fail on arm64 system which has 4 nodes[0...3], all have memory and CONFIG_NODES_SHIFT=2: migrate_pages01 0 TINFO : test_invalid_nodes migrate_pages01 14 TFAIL : migrate_pages_common.c:45: unexpected failure - returned value = 0, expected: -1 migrate_pages01 15 TFAIL : migrate_pages_common.c:55: call succeeded unexpectedly In this case the test_invalid_nodes of migrate_pages01 will call: SYSC_migrate_pages as: migrate_pages(0, , {0x0000000000000001}, 64, , {0x0000000000000010}, 64) = 0 The new nodes specifies one or more node IDs that are greater than the maximum supported node ID, however, the errno is not set to EINVAL as expected. As man pages of set_mempolicy[1], mbind[2], and migrate_pages[3] mentioned, when nodemask specifies one or more node IDs that are greater than the maximum supported node ID, the errno should set to EINVAL. However, get_nodes only check whether the part of bits [BITS_PER_LONG*BITS_TO_LONGS(MAX_NUMNODES), maxnode) is zero or not, and remain [MAX_NUMNODES, BITS_PER_LONG*BITS_TO_LONGS(MAX_NUMNODES) unchecked. This patch is to check the bits of [MAX_NUMNODES, maxnode) in get_nodes to let migrate_pages set the errno to EINVAL when nodemask specifies one or more node IDs that are greater than the maximum supported node ID, which follows the manpage's guide. [1] http://man7.org/linux/man-pages/man2/set_mempolicy.2.html [2] http://man7.org/linux/man-pages/man2/mbind.2.html [3] http://man7.org/linux/man-pages/man2/migrate_pages.2.html Link: http://lkml.kernel.org/r/1510882624-44342-3-git-send-email-xieyisheng1@huawei.com Signed-off-by:
Tan Xiaojun <tanxiaojun@huawei.com> Acked-by:
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- 25 Aug, 2017 1 commit
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zhong jiang authored
commit 73223e4e upstream. I hit a use after free issue when executing trinity and repoduced it with KASAN enabled. The related call trace is as follows. BUG: KASan: use after free in SyS_get_mempolicy+0x3c8/0x960 at addr ffff8801f582d766 Read of size 2 by task syz-executor1/798 INFO: Allocated in mpol_new.part.2+0x74/0x160 age=3 cpu=1 pid=799 __slab_alloc+0x768/0x970 kmem_cache_alloc+0x2e7/0x450 mpol_new.part.2+0x74/0x160 mpol_new+0x66/0x80 SyS_mbind+0x267/0x9f0 system_call_fastpath+0x16/0x1b INFO: Freed in __mpol_put+0x2b/0x40 age=4 cpu=1 pid=799 __slab_free+0x495/0x8e0 kmem_cache_free+0x2f3/0x4c0 __mpol_put+0x2b/0x40 SyS_mbind+0x383/0x9f0 system_call_fastpath+0x16/0x1b INFO: Slab 0xffffea0009cb8dc0 objects=23 used=8 fp=0xffff8801f582de40 flags=0x200000000004080 INFO: Object 0xffff8801f582d760 @offset=5984 fp=0xffff8801f582d600 Bytes b4 ffff8801f582d750: ae 01 ff ff 00 00 00 00 5a 5a 5a 5a 5a 5a 5a 5a ........ZZZZZZZZ Object ffff8801f582d760: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b kkkkkkkkkkkkkkkk Object ffff8801f582d770: 6b 6b 6b 6b 6b 6b 6b a5 kkkkkkk. Redzone ffff8801f582d778: bb bb bb bb bb bb bb bb ........ Padding ffff8801f582d8b8: 5a 5a 5a 5a 5a 5a 5a 5a ZZZZZZZZ Memory state around the buggy address: ffff8801f582d600: fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801f582d680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff8801f582d700: fc fc fc fc fc fc fc fc fc fc fc fc fb fb fb fc !shared memory policy is not protected against parallel removal by other thread which is normally protected by the mmap_sem. do_get_mempolicy, however, drops the lock midway while we can still access it later. Early premature up_read is a historical artifact from times when put_user was called in this path see https://lwn.net/Articles/124754/ but that is gone since 8bccd85f ("[PATCH] Implement sys_* do_* layering in the memory policy layer."). but when we have the the current mempolicy ref count model. The issue was introduced accordingly. Fix the issue by removing the premature release. Link: http://lkml.kernel.org/r/1502950924-27521-1-git-send-email-zhongjiang@huawei.com Signed-off-by:
zhong jiang <zhongjiang@huawei.com> Acked-by:
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- 12 Apr, 2017 1 commit
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Chris Salls authored
commit cf01fb99 upstream. In the case that compat_get_bitmap fails we do not want to copy the bitmap to the user as it will contain uninitialized stack data and leak sensitive data. Signed-off-by:
Chris Salls <salls@cs.ucsb.edu> Signed-off-by:
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- 01 Feb, 2017 1 commit
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Vlastimil Babka authored
commit d51e9894 upstream. Since commit be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") alloc_pages_vma() can potentially free a mempolicy by mpol_cond_put() before accessing the embedded nodemask by __alloc_pages_nodemask(). The commit log says it's so "we can use a single exit path within the function" but that's clearly wrong. We can still do that when doing mpol_cond_put() after the allocation attempt. Make sure the mempolicy is not freed prematurely, otherwise __alloc_pages_nodemask() can end up using a bogus nodemask, which could lead e.g. to premature OOM. Fixes: be97a41b ("mm/mempolicy.c: merge alloc_hugepage_vma to alloc_pages_vma") Link: http://lkml.kernel.org/r/20170118141124.8345-1-vbabka@suse.cz Signed-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by:
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- 19 Oct, 2016 1 commit
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Lorenzo Stoakes authored
This removes the 'write' and 'force' from get_user_pages() and replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by:
Lorenzo Stoakes <lstoakes@gmail.com> Acked-by:
Christian König <christian.koenig@amd.com> Acked-by:
Jesper Nilsson <jesper.nilsson@axis.com> Acked-by:
Jan Kara <jack@suse.cz> Signed-off-by:
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- 08 Oct, 2016 1 commit
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Aneesh Kumar K.V authored
Use the existing enums instead of hardcoded index when looking at the zonelist. This makes it more readable. No functionality change by this patch. Link: http://lkml.kernel.org/r/1472227078-24852-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com Signed-off-by:
Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Reviewed-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Signed-off-by:
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- 02 Sep, 2016 1 commit
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David Rientjes authored
KASAN allocates memory from the page allocator as part of kmem_cache_free(), and that can reference current->mempolicy through any number of allocation functions. It needs to be NULL'd out before the final reference is dropped to prevent a use-after-free bug: BUG: KASAN: use-after-free in alloc_pages_current+0x363/0x370 at addr ffff88010b48102c CPU: 0 PID: 15425 Comm: trinity-c2 Not tainted 4.8.0-rc2+ #140 ... Call Trace: dump_stack kasan_object_err kasan_report_error __asan_report_load2_noabort alloc_pages_current <-- use after free depot_save_stack save_stack kasan_slab_free kmem_cache_free __mpol_put <-- free do_exit This patch sets current->mempolicy to NULL before dropping the final reference. Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1608301442180.63329@chino.kir.corp.google.com Fixes: cd11016e ("mm, kasan: stackdepot implementation. Enable stackdepot for SLAB") Signed-off-by: David Ri...
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- 28 Jul, 2016 1 commit
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Mel Gorman authored
This moves the LRU lists from the zone to the node and related data such as counters, tracing, congestion tracking and writeback tracking. Unfortunately, due to reclaim and compaction retry logic, it is necessary to account for the number of LRU pages on both zone and node logic. Most reclaim logic is based on the node counters but the retry logic uses the zone counters which do not distinguish inactive and active sizes. It would be possible to leave the LRU counters on a per-zone basis but it's a heavier calculation across multiple cache lines that is much more frequent than the retry checks. Other than the LRU counters, this is mostly a mechanical patch but note that it introduces a number of anomalies. For example, the scans are per-zone but using per-node counters. We also mark a node as congested when a zone is congested. This causes weird problems that are fixed later but is easier to review. In the event that there is excessive overhead on 32-bit systems due to the nodes being on LRU then there are two potential solutions 1. Long-term isolation of highmem pages when reclaim is lowmem When pages are skipped, they are immediately added back onto the LRU list. If lowmem reclaim persisted for long periods of time, the same highmem pages get continually scanned. The idea would be that lowmem keeps those pages on a separate list until a reclaim for highmem pages arrives that splices the highmem pages back onto the LRU. It potentially could be implemented similar to the UNEVICTABLE list. That would reduce the skip rate with the potential corner case is that highmem pages have to be scanned and reclaimed to free lowmem slab pages. 2. Linear scan lowmem pages if the initial LRU shrink fails This will break LRU ordering but may be preferable and faster during memory pressure than skipping LRU pages. Link: http://lkml.kernel.org/r/1467970510-21195-4-git-send-email-mgorman@techsingularity.net Signed-off-by:
Johannes Weiner <hannes@cmpxchg.org> Acked-by:
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- 26 Jul, 2016 2 commits
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Kirill A. Shutemov authored
Here's basic implementation of huge pages support for shmem/tmpfs. It's all pretty streight-forward: - shmem_getpage() allcoates huge page if it can and try to inserd into radix tree with shmem_add_to_page_cache(); - shmem_add_to_page_cache() puts the page onto radix-tree if there's space for it; - shmem_undo_range() removes huge pages, if it fully within range. Partial truncate of huge pages zero out this part of THP. This have visible effect on fallocate(FALLOC_FL_PUNCH_HOLE) behaviour. As we don't really create hole in this case, lseek(SEEK_HOLE) may have inconsistent results depending what pages happened to be allocated. - no need to change shmem_fault: core-mm will map an compound page as huge if VMA is suitable; Link: http://lkml.kernel.org/r/1466021202-61880-30-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: -
Naoya Horiguchi authored
split_huge_pmd() doesn't guarantee that the pmd is normal pmd pointing to pte entries, which can be checked with pmd_trans_unstable(). Some callers make this assertion and some do it differently and some not, so let's do it in a unified manner. Link: http://lkml.kernel.org/r/1464741400-12143-1-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by:
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Hugh Dickins <hughd@google.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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- 20 May, 2016 3 commits
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Mel Gorman authored
The allocator fast path looks up the first usable zone in a zonelist and then get_page_from_freelist does the same job in the zonelist iterator. This patch preserves the necessary information. 4.6.0-rc2 4.6.0-rc2 fastmark-v1r20 initonce-v1r20 Min alloc-odr0-1 364.00 ( 0.00%) 359.00 ( 1.37%) Min alloc-odr0-2 262.00 ( 0.00%) 260.00 ( 0.76%) Min alloc-odr0-4 214.00 ( 0.00%) 214.00 ( 0.00%) Min alloc-odr0-8 186.00 ( 0.00%) 186.00 ( 0.00%) Min alloc-odr0-16 173.00 ( 0.00%) 173.00 ( 0.00%) Min alloc-odr0-32 165.00 ( 0.00%) 165.00 ( 0.00%) Min alloc-odr0-64 161.00 ( 0.00%) 162.00 ( -0.62%) Min alloc-odr0-128 159.00 ( 0.00%) 161.00 ( -1.26%) Min alloc-odr0-256 168.00 ( 0.00%) 170.00 ( -1.19%) Min alloc-odr0-512 180.00 ( 0.00%) 181.00 ( -0.56%) Min alloc-odr0-1024 190.00 ( 0.00%) 190.00 ( 0.00%) Min alloc-odr0-2048 196.00 ( 0.00%) 196.00 ( 0.00%) Min alloc-odr0-4096 202.00 ( 0.00%) 202.00 ( 0.00%) Min alloc-odr0-8192 206.00 ( 0.00%) 205.00 ( 0.49%) Min alloc-odr0-16384 206.00 ( 0.00%) 205.00 ( 0.49%) The benefit is negligible and the results are within the noise but each cycle counts. Signed-off-by: -
Andrew Morton authored
This code was pretty obscure and was relying upon obscure side-effects of next_node(-1, ...) and was relying upon NUMA_NO_NODE being equal to -1. Clean that all up and document the function's intent. Acked-by:
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Andrew Morton authored
Lots of code does node = next_node(node, XXX); if (node == MAX_NUMNODES) node = first_node(XXX); so create next_node_in() to do this and use it in various places. [mhocko@suse.com: use next_node_in() helper] Acked-by:
Michal Hocko <mhocko@kernel.org> Signed-off-by:
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- 17 Mar, 2016 1 commit
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Joe Perches authored
Kernel style prefers a single string over split strings when the string is 'user-visible'. Miscellanea: - Add a missing newline - Realign arguments Signed-off-by:
Joe Perches <joe@perches.com> Acked-by: Tejun Heo <tj@kernel.org> [percpu] Signed-off-by:
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- 15 Mar, 2016 1 commit
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Liang Chen authored
VM_HUGETLB and VM_MIXEDMAP vma needs to be excluded to avoid compound pages being marked for migration and unexpected COWs when handling hugetlb fault. Thanks to Naoya Horiguchi for reminding me on these checks. Signed-off-by:
Liang Chen <liangchen.linux@gmail.com> Signed-off-by:
Gavin Guo <gavin.guo@canonical.com> Suggested-by:
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- 09 Mar, 2016 1 commit
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Kirill A. Shutemov authored
We don't have native support of THP migration, so we have to split huge page into small pages in order to migrate it to different node. This includes PTE-mapped huge pages. I made mistake in refcounting patchset: we don't actually split PTE-mapped huge page in queue_pages_pte_range(), if we step on head page. The result is that the head page is queued for migration, but none of tail pages: putting head page on queue takes pin on the page and any subsequent attempts of split_huge_pages() would fail and we skip queuing tail pages. unmap_and_move_huge_page() will eventually split the huge pages, but only one of 512 pages would get migrated. Let's fix the situation. Fixes: 248db92d ("migrate_pages: try to split pages on queuing") Signed-off-by:
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- 16 Feb, 2016 1 commit
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Dave Hansen authored
We will soon modify the vanilla get_user_pages() so it can no longer be used on mm/tasks other than 'current/current->mm', which is by far the most common way it is called. For now, we allow the old-style calls, but warn when they are used. (implemented in previous patch) This patch switches all callers of: get_user_pages() get_user_pages_unlocked() get_user_pages_locked() to stop passing tsk/mm so they will no longer see the warnings. Signed-off-by:
Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave@sr71.net> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: jack@suse.cz Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/20160212210156.113E9407@viggo.jf.intel.com Signed-off-by:
Ingo Molnar <mingo@kernel.org>
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- 06 Feb, 2016 1 commit
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Kirill A. Shutemov authored
Maybe I miss some point, but I don't see a reason why we try to queue pages from non migratable VMAs. This testcase steps on VM_BUG_ON_PAGE() in isolate_lru_page(): #include <fcntl.h> #include <unistd.h> #include <stdio.h> #include <sys/mman.h> #include <numaif.h> #define SIZE 0x2000 int foo; int main() { int fd; char *p; unsigned long mask = 2; fd = open("/dev/sg0", O_RDWR); p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE, fd, 0); /* Faultin pages */ foo = p[0] + p[0x1000]; mbind(p, SIZE, MPOL_BIND, &mask, 4, MPOL_MF_MOVE | MPOL_MF_STRICT); return 0; } The only case when we can queue pages from such VMA is MPOL_MF_STRICT plus MPOL_MF_MOVE or MPOL_MF_MOVE_ALL for VMA which has pages on LRU, but gfp mask is not sutable for migaration (see mapping_gfp_mask() check in vma_migratable()). That's looks like a bug to me. Let's filter out non-migratable vma at start of queue_pages_test_walk() and go to queue_pages_pte_range() only if MPOL_MF_MOVE or MPOL_MF_MOVE_ALL flag is set. Signed-off-by:Dmitry Vyukov <dvyukov@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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- 16 Jan, 2016 3 commits
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Liang Chen authored
MPOL_MF_LAZY is not visible from userspace since a720094d ("mm: mempolicy: Hide MPOL_NOOP and MPOL_MF_LAZY from userspace for now"), but it should still skip non-migratable VMAs such as VM_IO, VM_PFNMAP, and VM_HUGETLB VMAs, and avoid useless overhead of minor faults. Signed-off-by:
Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andi Kleen <andi@firstfloor.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by:
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Kirill A. Shutemov authored
We are not able to migrate THPs. It means it's not enough to split only PMD on migration -- we need to split compound page under it too. Signed-off-by:
Jerome Marchand <jmarchan@redhat.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by:
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Kirill A. Shutemov authored
We are going to decouple splitting THP PMD from splitting underlying compound page. This patch renames split_huge_page_pmd*() functions to split_huge_pmd*() to reflect the fact that it doesn't imply page splitting, only PMD. Signed-off-by:
Sasha Levin <sasha.levin@oracle.com> Tested-by:
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- 15 Jan, 2016 1 commit
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Nathan Zimmer authored
When running the SPECint_rate gcc on some very large boxes it was noticed that the system was spending lots of time in mpol_shared_policy_lookup(). The gamess benchmark can also show it and is what I mostly used to chase down the issue since the setup for that I found to be easier. To be clear the binaries were on tmpfs because of disk I/O requirements. We then used text replication to avoid icache misses and having all the copies banging on the memory where the instruction code resides. This results in us hitting a bottleneck in mpol_shared_policy_lookup() since lookup is serialised by the shared_policy lock. I have only reproduced this on very large (3k+ cores) boxes. The problem starts showing up at just a few hundred ranks getting worse until it threatens to livelock once it gets large enough. For example on the gamess benchmark at 128 ranks this area consumes only ~1% of time, at 512 ranks it consumes nearly 13%, and at 2k ranks it is over 90%. To alleviate the contention in this area I converted the spinlock to an rwlock. This allows a large number of lookups to happen simultaneously. The results were quite good reducing this consumtion at max ranks to around 2%. [akpm@linux-foundation.org: tidy up code comments] Signed-off-by:
Nathan Zimmer <nzimmer@sgi.com> Acked-by:
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- 08 Sep, 2015 2 commits
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Vlastimil Babka authored
alloc_pages_exact_node() was introduced in commit 6484eb3e ("page allocator: do not check NUMA node ID when the caller knows the node is valid") as an optimized variant of alloc_pages_node(), that doesn't fallback to current node for nid == NUMA_NO_NODE. Unfortunately the name of the function can easily suggest that the allocation is restricted to the given node and fails otherwise. In truth, the node is only preferred, unless __GFP_THISNODE is passed among the gfp flags. The misleading name has lead to mistakes in the past, see for example commits 5265047a ("mm, thp: really limit transparent hugepage allocation to local node") and b360edb4 ("mm, mempolicy: migrate_to_node should only migrate to node"). Another issue with the name is that there's a family of alloc_pages_exact*() functions where 'exact' means exact size (instead of page order), which leads to more confusion. To prevent further mistakes, this patch effectively rena...
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Aristeu Rozanski authored
This check was introduced as part of 6f4576e3 ("mempolicy: apply page table walker on queue_pages_range()") which got duplicated by 48684a65 ("mm: pagewalk: fix misbehavior of walk_page_range for vma(VM_PFNMAP)") by reintroducing it earlier on queue_page_test_walk() Signed-off-by:
Aristeu Rozanski <aris@redhat.com> Acked-by:
Cyrill Gorcunov <gorcunov@openvz.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by:
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- 04 Sep, 2015 1 commit
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Andrea Arcangeli authored
vma->vm_userfaultfd_ctx is yet another vma parameter that vma_merge must be aware about so that we can merge vmas back like they were originally before arming the userfaultfd on some memory range. Signed-off-by:
Pavel Emelyanov <xemul@parallels.com> Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Cc: zhang.zhanghailiang@huawei.com Cc: "Kirill A. Shutemov" <kirill@shutemov.name> Cc: Andres Lagar-Cavilla <andreslc@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hugh Dickins <hughd@google.com> Cc: Peter Feiner <pfeiner@google.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com> Signed-off-by:
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- 25 Jun, 2015 1 commit
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Vlastimil Babka authored
Since commit 077fcf11 ("mm/thp: allocate transparent hugepages on local node"), we handle THP allocations on page fault in a special way - for non-interleave memory policies, the allocation is only attempted on the node local to the current CPU, if the policy's nodemask allows the node. This is motivated by the assumption that THP benefits cannot offset the cost of remote accesses, so it's better to fallback to base pages on the local node (which might still be available, while huge pages are not due to fragmentation) than to allocate huge pages on a remote node. The nodemask check prevents us from violating e.g. MPOL_BIND policies where the local node is not among the allowed nodes. However, the current implementation can still give surprising results for the MPOL_PREFERRED policy when the preferred node is different than the current CPU's local node. In such case we should honor the preferred node and not use the local node, which is what this patch does. If hugepage allocation on the preferred node fails, we fall back to base pages and don't try other nodes, with the same motivation as is done for the local node hugepage allocations. The patch also moves the MPOL_INTERLEAVE check around to simplify the hugepage specific test. The difference can be demonstrated using in-tree transhuge-stress test on the following 2-node machine where half memory on one node was occupied to show the difference. > numactl --hardware available: 2 nodes (0-1) node 0 cpus: 0 1 2 3 4 5 6 7 8 9 10 11 24 25 26 27 28 29 30 31 32 33 34 35 node 0 size: 7878 MB node 0 free: 3623 MB node 1 cpus: 12 13 14 15 16 17 18 19 20 21 22 23 36 37 38 39 40 41 42 43 44 45 46 47 node 1 size: 8045 MB node 1 free: 7818 MB node distances: node 0 1 0: 10 21 1: 21 10 Before the patch: > numactl -p0 -C0 ./transhuge-stress transhuge-stress: 2.197 s/loop, 0.276 ms/page, 7249.168 MiB/s 7962 succeed, 0 failed, 1786 different pages > numactl -p0 -C12 ./transhuge-stress transhuge-stress: 2.962 s/loop, 0.372 ms/page, 5376.172 MiB/s 7962 succeed, 0 failed, 3873 different pages Number of successful THP allocations corresponds to free memory on node 0 in the first case and node 1 in the second case, i.e. -p parameter is ignored and cpu binding "wins". After the patch: > numactl -p0 -C0 ./transhuge-stress transhuge-stress: 2.183 s/loop, 0.274 ms/page, 7295.516 MiB/s 7962 succeed, 0 failed, 1760 different pages > numactl -p0 -C12 ./transhuge-stress transhuge-stress: 2.878 s/loop, 0.361 ms/page, 5533.638 MiB/s 7962 succeed, 0 failed, 1750 different pages > numactl -p1 -C0 ./transhuge-stress transhuge-stress: 4.628 s/loop, 0.581 ms/page, 3440.893 MiB/s 7962 succeed, 0 failed, 3918 different pages The -p parameter is respected regardless of cpu binding. > numactl -C0 ./transhuge-stress transhuge-stress: 2.202 s/loop, 0.277 ms/page, 7230.003 MiB/s 7962 succeed, 0 failed, 1750 different pages > numactl -C12 ./transhuge-stress transhuge-stress: 3.020 s/loop, 0.379 ms/page, 5273.324 MiB/s 7962 succeed, 0 failed, 3916 different pages Without -p parameter, hugepage restriction to CPU-local node works as before. Fixes: 077fcf11 ("mm/thp: allocate transparent hugepages on local node") Signed-off-by:
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- 15 May, 2015 1 commit
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Mel Gorman authored
NUMA balancing is meant to be disabled by default on UMA machines but the check is using nr_node_ids (highest node) instead of num_online_nodes (online nodes). The consequences are that a UMA machine with a node ID of 1 or higher will enable NUMA balancing. This will incur useless overhead due to minor faults with the impact depending on the workload. These are the impact on the stats when running a kernel build on a single node machine whose node ID happened to be 1: vanilla patched NUMA base PTE updates 5113158 0 NUMA huge PMD updates 643 0 NUMA page range updates 5442374 0 NUMA hint faults 2109622 0 NUMA hint local faults 2109622 0 NUMA hint local percent 100 100 NUMA pages migrated 0 0 Signed-off-by:
Mel Gorman <mgorman@suse.de> Reviewed-by:
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- 14 Apr, 2015 2 commits
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David Rientjes authored
Commit 077fcf11 ("mm/thp: allocate transparent hugepages on local node") restructured alloc_hugepage_vma() with the intent of only allocating transparent hugepages locally when there was not an effective interleave mempolicy. alloc_pages_exact_node() does not limit the allocation to the single node, however, but rather prefers it. This is because __GFP_THISNODE is not set which would cause the node-local nodemask to be passed. Without it, only a nodemask that prefers the local node is passed. Fix this by passing __GFP_THISNODE and falling back to small pages when the allocation fails. Commit 9f1b868a ("mm: thp: khugepaged: add policy for finding target node") suffers from a similar problem for khugepaged, which is also fixed. Fixes: 077fcf11 ("mm/thp: allocate transparent hugepages on local node") Fixes: 9f1b868a ("mm: thp: khugepaged: add policy for finding target node") Signed-off-by:
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David Rientjes authored
migrate_to_node() is intended to migrate a page from one source node to a target node. Today, migrate_to_node() could end up migrating to any node, not only the target node. This is because the page migration allocator, new_node_page() does not pass __GFP_THISNODE to alloc_pages_exact_node(). This causes the target node to be preferred but allows fallback to any other node in order of affinity. Prevent this by allocating with __GFP_THISNODE. If memory is not available, -ENOMEM will be returned as appropriate. Signed-off-by:
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- 14 Feb, 2015 1 commit
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Tejun Heo authored
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. Signed-off-by:
Tejun Heo <tj@kernel.org> Signed-off-by:
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- 13 Feb, 2015 1 commit
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Mel Gorman authored
With PROT_NONE, the traditional page table manipulation functions are sufficient. [andre.przywara@arm.com: fix compiler warning in pmdp_invalidate()] [akpm@linux-foundation.org: fix build with STRICT_MM_TYPECHECKS] Signed-off-by:
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- 12 Feb, 2015 4 commits
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Naoya Horiguchi authored
walk_page_range() silently skips vma having VM_PFNMAP set, which leads to undesirable behaviour at client end (who called walk_page_range). For example for pagemap_read(), when no callbacks are called against VM_PFNMAP vma, pagemap_read() may prepare pagemap data for next virtual address range at wrong index. That could confuse and/or break userspace applications. This patch avoid this misbehavior caused by vma(VM_PFNMAP) like follows: - for pagemap_read() which has its own ->pte_hole(), call the ->pte_hole() over vma(VM_PFNMAP), - for clear_refs and queue_pages which have their own ->tests_walk, just return 1 and skip vma(VM_PFNMAP). This is no problem because these are not interested in hole regions, - for other callers, just skip the vma(VM_PFNMAP) as a default behavior. Signed-off-by:
Shiraz Hashim <shashim@codeaurora.org> Signed-off-by:
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Naoya Horiguchi authored
queue_pages_range() does page table walking in its own way now, but there is some code duplicate. This patch applies page table walker to reduce lines of code. queue_pages_range() has to do some precheck to determine whether we really walk over the vma or just skip it. Now we have test_walk() callback in mm_walk for this purpose, so we can do this replacement cleanly. queue_pages_test_walk() depends on not only the current vma but also the previous one, so queue_pages->prev is introduced to remember it. Signed-off-by:
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Vlastimil Babka authored
The previous commit ("mm/thp: Allocate transparent hugepages on local node") introduced alloc_hugepage_vma() to mm/mempolicy.c to perform a special policy for THP allocations. The function has the same interface as alloc_pages_vma(), shares a lot of boilerplate code and a long comment. This patch merges the hugepage special case into alloc_pages_vma. The extra if condition should be cheap enough price to pay. We also prevent a (however unlikely) race with parallel mems_allowed update, which could make hugepage allocation restart only within the fallback call to alloc_hugepage_vma() and not reconsider the special rule in alloc_hugepage_vma(). Also by making sure mpol_cond_put(pol) is always called before actual allocation attempt, we can use a single exit path within the function. Also update the comment for missing node parameter and obsolete reference to mm_sem. Signed-off-by: -
Aneesh Kumar K.V authored
This make sure that we try to allocate hugepages from local node if allowed by mempolicy. If we can't, we fallback to small page allocation based on mempolicy. This is based on the observation that allocating pages on local node is more beneficial than allocating hugepages on remote node. With this patch applied we may find transparent huge page allocation failures if the current node doesn't have enough freee hugepages. Before this patch such failures result in us retrying the allocation on other nodes in the numa node mask. [akpm@linux-foundation.org: fix comment, add CONFIG_TRANSPARENT_HUGEPAGE dependency] Signed-off-by:
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