- 10 Jul, 2017 40 commits
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Arvind Yadav authored
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 8293 841 4 9138 23b2 drivers/block/zram/zram_drv.o File size After adding 'const': text data bss dec hex filename 8357 777 4 9138 23b2 drivers/block/zram/zram_drv.o Link: http://lkml.kernel.org/r/65680c1c4d85818f7094cbfa31c91bf28185ba1b.1499061182.git.arvind.yadav.cs@gmail.comSigned-off-by:
Arvind Yadav <arvind.yadav.cs@gmail.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Michal Hocko authored
early_pfn_to_nid will return node 0 if both HAVE_ARCH_EARLY_PFN_TO_NID and HAVE_MEMBLOCK_NODE_MAP are disabled. It seems we are safe now because all architectures which support NUMA define one of them (with an exception of alpha which however has CONFIG_NUMA marked as broken) so this works as expected. It can get silently and subtly broken too easily, though. Make sure we fail the compilation if NUMA is enabled and there is no proper implementation for this function. If that ever happens we know that either the specific configuration is invalid and the fix should either disable NUMA or enable one of the above configs. Link: http://lkml.kernel.org/r/20170704075803.15979-1-mhocko@kernel.orgSigned-off-by:
Michal Hocko <mhocko@suse.com> Acked-by:
Vlastimil Babka <vbabka@suse.cz> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Yang Shi <yang.shi@linaro.org> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by:
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Thomas Gleixner authored
Andrey reported a potential deadlock with the memory hotplug lock and the cpu hotplug lock. The reason is that memory hotplug takes the memory hotplug lock and then calls stop_machine() which calls get_online_cpus(). That's the reverse lock order to get_online_cpus(); get_online_mems(); in mm/slub_common.c The problem has been there forever. The reason why this was never reported is that the cpu hotplug locking had this homebrewn recursive reader writer semaphore construct which due to the recursion evaded the full lock dep coverage. The memory hotplug code copied that construct verbatim and therefor has similar issues. Three steps to fix this: 1) Convert the memory hotplug locking to a per cpu rwsem so the potential issues get reported proper by lockdep. 2) Lock the online cpus in mem_hotplug_begin() before taking the memory hotplug rwsem and use stop_machine_cpuslocked() in the page_alloc code to avoid recursive locking. 3) The cpu hotpluck locking in #2 causes a recursive locking of the cpu hotplug lock via __offline_pages() -> lru_add_drain_all(). Solve this by invoking lru_add_drain_all_cpuslocked() instead. Link: http://lkml.kernel.org/r/20170704093421.506836322@linutronix.deReported-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by:
Thomas Gleixner <tglx@linutronix.de> Acked-by:
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Thomas Gleixner authored
The rework of the cpu hotplug locking unearthed potential deadlocks with the memory hotplug locking code. The solution for these is to rework the memory hotplug locking code as well and take the cpu hotplug lock before the memory hotplug lock in mem_hotplug_begin(), but this will cause a recursive locking of the cpu hotplug lock when the memory hotplug code calls lru_add_drain_all(). Split out the inner workings of lru_add_drain_all() into lru_add_drain_all_cpuslocked() so this function can be invoked from the memory hotplug code with the cpu hotplug lock held. Link: http://lkml.kernel.org/r/20170704093421.419329357@linutronix.deSigned-off-by:
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Krzysztof Opasiak authored
Use rlimit() helper instead of manually writing whole chain from current task to rlim_cur. Link: http://lkml.kernel.org/r/20170705172811.8027-1-k.opasiak@samsung.comSigned-off-by:
Krzysztof Opasiak <k.opasiak@samsung.com> Signed-off-by:
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Sahitya Tummala authored
__list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer duration if there are more number of items in the lru list. As per the current code, it can hold the spin lock for upto maximum UINT_MAX entries at a time. So if there are more number of items in the lru list, then "BUG: spinlock lockup suspected" is observed in the below path: spin_bug+0x90 do_raw_spin_lock+0xfc _raw_spin_lock+0x28 list_lru_add+0x28 dput+0x1c8 path_put+0x20 terminate_walk+0x3c path_lookupat+0x100 filename_lookup+0x6c user_path_at_empty+0x54 SyS_faccessat+0xd0 el0_svc_naked+0x24 This nlru->lock is acquired by another CPU in this path - d_lru_shrink_move+0x34 dentry_lru_isolate_shrink+0x48 __list_lru_walk_one.isra.10+0x94 list_lru_walk_node+0x40 shrink_dcache_sb+0x60 do_remount_sb+0xbc do_emergency_remount+0xb0 process_one_work+0x228 worker_thread+0x2e0 kthread+0xf4 ret_from_fork+0x10 Fix this lockup by reducing the number of entries to be shrinked from the lru list to 1024 at once. Also, add cond_resched() before processing the lru list again. Link: http://marc.info/?t=149722864900001&r=1&w=2 Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.orgSigned-off-by:
Sahitya Tummala <stummala@codeaurora.org> Suggested-by:
Jan Kara <jack@suse.cz> Suggested-by:
Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by:
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Sahitya Tummala authored
list_lru_count_node() iterates over all memcgs to get the total number of entries on the node but it can race with memcg_drain_all_list_lrus(), which migrates the entries from a dead cgroup to another. This can return incorrect number of entries from list_lru_count_node(). Fix this by keeping track of entries per node and simply return it in list_lru_count_node(). Link: http://lkml.kernel.org/r/1498707555-30525-1-git-send-email-stummala@codeaurora.orgSigned-off-by:
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Oleg Nesterov authored
expand_stack(vma) fails if address < stack_guard_gap even if there is no vma->vm_prev. I don't think this makes sense, and we didn't do this before the recent commit 1be7107f ("mm: larger stack guard gap, between vmas"). We do not need a gap in this case, any address is fine as long as security_mmap_addr() doesn't object. This also simplifies the code, we know that address >= prev->vm_end and thus underflow is not possible. Link: http://lkml.kernel.org/r/20170628175258.GA24881@redhat.comSigned-off-by:
Oleg Nesterov <oleg@redhat.com> Acked-by:
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Michal Hocko authored
Commit 1be7107f ("mm: larger stack guard gap, between vmas") has introduced a regression in some rust and Java environments which are trying to implement their own stack guard page. They are punching a new MAP_FIXED mapping inside the existing stack Vma. This will confuse expand_{downwards,upwards} into thinking that the stack expansion would in fact get us too close to an existing non-stack vma which is a correct behavior wrt safety. It is a real regression on the other hand. Let's work around the problem by considering PROT_NONE mapping as a part of the stack. This is a gros hack but overflowing to such a mapping would trap anyway an we only can hope that usespace knows what it is doing and handle it propely. Fixes: 1be7107f ("mm: larger stack guard gap, between vmas") Link: http://lkml.kernel.org/r/20170705182849.GA18027@dhcp22.suse.czSigned-off-by:
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zhenwei.pi authored
presently pages in the balloon device have random value, and these pages will be scanned by ksmd on the host. They usually cannot be merged. Enqueue zero pages will resolve this problem. Link: http://lkml.kernel.org/r/1498698637-26389-1-git-send-email-zhenwei.pi@youruncloud.comSigned-off-by:
zhenwei.pi <zhenwei.pi@youruncloud.com> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Minchan Kim <minchan@kernel.org> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Rafael Aquini <aquini@redhat.com> Signed-off-by:
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Doug Berger authored
The align_offset parameter is used by bitmap_find_next_zero_area_off() to represent the offset of map's base from the previous alignment boundary; the function ensures that the returned index, plus the align_offset, honors the specified align_mask. The logic introduced by commit b5be83e3 ("mm: cma: align to physical address, not CMA region position") has the cma driver calculate the offset to the *next* alignment boundary. In most cases, the base alignment is greater than that specified when making allocations, resulting in a zero offset whether we align up or down. In the example given with the commit, the base alignment (8MB) was half the requested alignment (16MB) so the math also happened to work since the offset is 8MB in both directions. However, when requesting allocations with an alignment greater than twice that of the base, the returned index would not be correctly aligned. Also, the align_order arguments of cma_bitmap_aligned_mask() and cma_bitmap_aligned_offset() should not be negative so the argument type was made unsigned. Fixes: b5be83e3 ("mm: cma: align to physical address, not CMA region position") Link: http://lkml.kernel.org/r/20170628170742.2895-1-opendmb@gmail.comSigned-off-by:
Angus Clark <angus@angusclark.org> Signed-off-by:
Doug Berger <opendmb@gmail.com> Acked-by:
Gregory Fong <gregory.0xf0@gmail.com> Cc: Doug Berger <opendmb@gmail.com> Cc: Angus Clark <angus@angusclark.org> Cc: Laura Abbott <labbott@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Lucas Stach <l.stach@pengutronix.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Shiraz Hashim <shashim@codeaurora.org> Cc: Jaewon Kim <jaewon31.kim@samsung.com> Signed-off-by:
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John Hubbard authored
__remove_zone() sets up up zone_type, but never uses it for anything. This does not cause a warning, due to the (necessary) use of -Wno-unused-but-set-variable. However, it's noise, so just delete it. Link: http://lkml.kernel.org/r/20170624043421.24465-2-jhubbard@nvidia.comSigned-off-by:
John Hubbard <jhubbard@nvidia.com> Acked-by:
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Michal Hocko authored
It seems that there are still people using 32b kernels which a lot of memory and the IO tend to suck a lot for them by default. Mostly because writers are throttled too when the lowmem is used. We have highmem_is_dirtyable to work around that issue but it seems we never bothered to document it. Let's do it now, finally. Link: http://lkml.kernel.org/r/20170626093200.18958-1-mhocko@kernel.orgSigned-off-by:
Johannes Weiner <hannes@cmpxchg.org> Cc: Alkis Georgopoulos <alkisg@gmail.com> Cc: Mel Gorman <mgorman@suse.de> Signed-off-by:
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Nikolay Borisov authored
wb_stat_sum() disables interrupts and calls __wb_stat_sum() which eventually calls __percpu_counter_sum(). However, the percpu routine is already irq-safe. Simplify the code a bit by making wb_stat_sum() directly call percpu_counter_sum_positive() and not disable interrupts. Also remove the now-uneeded __wb_stat_sum() which was just a wrapper over percpu_counter_sum_positive(). Link: http://lkml.kernel.org/r/1498230681-29103-1-git-send-email-nborisov@suse.comSigned-off-by:
Nikolay Borisov <nborisov@suse.com> Acked-by:
Peter Zijlstra <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@fb.com> Signed-off-by:
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Nikolay Borisov authored
Currently pg_data_t is just a struct which describes a NUMA node memory layout. Let's keep the comment simple and remove ambiguity. Link: http://lkml.kernel.org/r/1498220534-22717-1-git-send-email-nborisov@suse.comSigned-off-by:
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Sebastian Andrzej Siewior authored
get_cpu_var() disables preemption and returns the per-CPU version of the variable. Disabling preemption is useful to ensure atomic access to the variable within the critical section. In this case however, after the per-CPU version of the variable is obtained the ->free_lock is acquired. For that reason it seems the raw accessor could be used. It only seems that ->slots_ret should be retested (because with disabled preemption this variable can not be set to NULL otherwise). This popped up during PREEMPT-RT testing because it tries to take spinlocks in a preempt disabled section. In RT, spinlocks can sleep. Link: http://lkml.kernel.org/r/20170623114755.2ebxdysacvgxzott@linutronix.deSigned-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Acked-by:
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Rasmus Villemoes authored
Since current_order starts as MAX_ORDER-1 and is then only decremented, the second half of the loop condition seems superfluous. However, if order is 0, we may decrement current_order past 0, making it UINT_MAX. This is obviously too subtle ([1], [2]). Since we need to add some comment anyway, change the two variables to signed, making the counting-down for loop look more familiar, and apparently also making gcc generate slightly smaller code. [1] https://lkml.org/lkml/2016/6/20/493 [2] https://lkml.org/lkml/2017/6/19/345 [akpm@linux-foundation.org: fix up reject fixupping] Link: http://lkml.kernel.org/r/20170621185529.2265-1-linux@rasmusvillemoes.dkSigned-off-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Reported-by:
Hao Lee <haolee.swjtu@gmail.com> Acked-by:
Wei Yang <weiyang@gmail.com> Acked-by:
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Vasily Averin authored
After commit 1be7107f ("mm: larger stack guard gap, between vmas") we do not hide stack guard page in /proc/<pid>/maps Link: http://lkml.kernel.org/r/211f3c2a-f7ef-7c13-82bf-46fd426f6e1b@virtuozzo.comSigned-off-by:
Vasily Averin <vvs@virtuozzo.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by:
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Dou Liyang authored
__register_one_node() initializes local parameters "p_node" & "parent" for register_node(). But, register_node() does not use them. Remove the related code of "parent" node, cleanup __register_one_node() and register_node(). Link: http://lkml.kernel.org/r/1498013846-20149-1-git-send-email-douly.fnst@cn.fujitsu.comSigned-off-by:
Dou Liyang <douly.fnst@cn.fujitsu.com> Acked-by:
David Rientjes <rientjes@google.com> Acked-by:
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Vinayak Menon authored
pagetypeinfo_showmixedcount_print is found to take a lot of time to complete and it does this holding the zone lock and disabling interrupts. In some cases it is found to take more than a second (On a 2.4GHz,8Gb RAM,arm64 cpu). Avoid taking the zone lock similar to what is done by read_page_owner, which means possibility of inaccurate results. Link: http://lkml.kernel.org/r/1498045643-12257-1-git-send-email-vinmenon@codeaurora.orgSigned-off-by:
Vinayak Menon <vinmenon@codeaurora.org> Acked-by:
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Michal Hocko authored
new_page is yet another duplication of the migration callback which has to handle hugetlb migration specially. We can safely use the generic new_page_nodemask for the same purpose. Please note that gigantic hugetlb pages do not need any special handling because alloc_huge_page_nodemask will make sure to check pages in all per node pools. The reason this was done previously was that alloc_huge_page_node treated NO_NUMA_NODE and a specific node differently and so alloc_huge_page_node(nid) would check on this specific node. Link: http://lkml.kernel.org/r/20170622193034.28972-4-mhocko@kernel.orgSigned-off-by:
Mike Kravetz <mike.kravetz@oracle.com> Tested-by:
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Michal Hocko authored
alloc_huge_page_nodemask tries to allocate from any numa node in the allowed node mask starting from lower numa nodes. This might lead to filling up those low NUMA nodes while others are not used. We can reduce this risk by introducing a concept of the preferred node similar to what we have in the regular page allocator. We will start allocating from the preferred nid and then iterate over all allowed nodes in the zonelist order until we try them all. This is mimicing the page allocator logic except it operates on per-node mempools. dequeue_huge_page_vma already does this so distill the zonelist logic into a more generic dequeue_huge_page_nodemask and use it in alloc_huge_page_nodemask. This will allow us to use proper per numa distance fallback also for alloc_huge_page_node which can use alloc_huge_page_nodemask now and we can get rid of alloc_huge_page_node helper which doesn't have any user anymore. Link: http://lkml.kernel.org/r/20170622193034.28972-3-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
Patch series "mm, hugetlb: allow proper node fallback dequeue". While working on a hugetlb migration issue addressed in a separate patchset[1] I have noticed that the hugetlb allocations from the preallocated pool are quite subotimal. [1] //lkml.kernel.org/r/20170608074553.22152-1-mhocko@kernel.org There is no fallback mechanism implemented and no notion of preferred node. I have tried to work around it but Vlastimil was right to push back for a more robust solution. It seems that such a solution is to reuse zonelist approach we use for the page alloctor. This series has 3 patches. The first one tries to make hugetlb allocation layers more clear. The second one implements the zonelist hugetlb pool allocation and introduces a preferred node semantic which is used by the migration callbacks. The last patch is a clean up. This patch (of 3): Hugetlb allocation path for fresh huge pages is unnecessarily complex and it mixes different interfaces between layers. __alloc_buddy_huge_page is the central place to perform a new allocation. It checks for the hugetlb overcommit and then relies on __hugetlb_alloc_buddy_huge_page to invoke the page allocator. This is all good except that __alloc_buddy_huge_page pushes vma and address down the callchain and so __hugetlb_alloc_buddy_huge_page has to deal with two different allocation modes - one for memory policy and other node specific (or to make it more obscure node non-specific) requests. This just screams for a reorganization. This patch pulls out all the vma specific handling up to __alloc_buddy_huge_page_with_mpol where it belongs. __alloc_buddy_huge_page will get nodemask argument and __hugetlb_alloc_buddy_huge_page will become a trivial wrapper over the page allocator. In short: __alloc_buddy_huge_page_with_mpol - memory policy handling __alloc_buddy_huge_page - overcommit handling and accounting __hugetlb_alloc_buddy_huge_page - page allocator layer Also note that __hugetlb_alloc_buddy_huge_page and its cpuset retry loop is not really needed because the page allocator already handles the cpusets update. Finally __hugetlb_alloc_buddy_huge_page had a special case for node specific allocations (when no policy is applied and there is a node given). This has relied on __GFP_THISNODE to not fallback to a different node. alloc_huge_page_node is the only caller which relies on this behavior so move the __GFP_THISNODE there. Not only does this remove quite some code it also should make those layers easier to follow and clear wrt responsibilities. Link: http://lkml.kernel.org/r/20170622193034.28972-2-mhocko@kernel.orgSigned-off-by: -
Roman Gushchin authored
During the debugging of the problem described in https://lkml.org/lkml/2017/5/17/542 and fixed by Tetsuo Handa in https://lkml.org/lkml/2017/5/19/383 , I've found that the existing debug output is not really useful to understand issues related to the oom reaper. So, I assume, that adding some tracepoints might help with debugging of similar issues. Trace the following events: 1) a process is marked as an oom victim, 2) a process is added to the oom reaper list, 3) the oom reaper starts reaping process's mm, 4) the oom reaper finished reaping, 5) the oom reaper skips reaping. How it works in practice? Below is an example which show how the problem mentioned above can be found: one process is added twice to the oom_reaper list: $ cd /sys/kernel/debug/tracing $ echo "oom:mark_victim" > set_event $ echo "oom:wake_reaper" >> set_event $ echo "oom:skip_task_reaping" >> set_event $ echo "oom:start_task_reaping" >> set_event $ echo "oom:finish_task_reaping" >> set_event $ cat trace_pipe allocate-502 [001] .... 91.836405: mark_victim: pid=502 allocate-502 [001] .N.. 91.837356: wake_reaper: pid=502 allocate-502 [000] .N.. 91.871149: wake_reaper: pid=502 oom_reaper-23 [000] .... 91.871177: start_task_reaping: pid=502 oom_reaper-23 [000] .N.. 91.879511: finish_task_reaping: pid=502 oom_reaper-23 [000] .... 91.879580: skip_task_reaping: pid=502 Link: http://lkml.kernel.org/r/20170530185231.GA13412@castleSigned-off-by:
Roman Gushchin <guro@fb.com> Acked-by:
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Mike Rapoport authored
MADV_FREE is identical to MADV_DONTNEED from the point of view of uffd monitor. The monitor has to stop handling #PF events in the range being freed. We are reusing userfaultfd_remove callback along with the logic required to re-get and re-validate the VMA which may change or disappear because userfaultfd_remove releases mmap_sem. Link: http://lkml.kernel.org/r/1497876311-18615-1-git-send-email-rppt@linux.vnet.ibm.comSigned-off-by:
Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Signed-off-by:
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Jan Kara authored
The condition checking for THP straddling end of invalidated range is wrong - it checks 'index' against 'end' but 'index' has been already advanced to point to the end of THP and thus the condition can never be true. As a result THP straddling 'end' has been fully invalidated. Given the nature of invalidate_mapping_pages(), this could be only performance issue. In fact, we are lucky the condition is wrong because if it was ever true, we'd leave locked page behind. Fix the condition checking for THP straddling 'end' and also properly unlock the page. Also update the comment before the condition to explain why we decide not to invalidate the page as it was not clear to me and I had to ask Kirill. Link: http://lkml.kernel.org/r/20170619124723.21656-1-jack@suse.czSigned-off-by:
Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
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Matthew Wilcox authored
The hugetlb code has its own function to report human-readable sizes. Convert it to use the shared string_get_size() function. This will lead to a minor difference in user visible output (MiB/GiB instead of MB/GB), but some would argue that's desirable anyway. Link: http://lkml.kernel.org/r/20170606190350.GA20010@bombadil.infradead.orgSigned-off-by:
Matthew Wilcox <mawilcox@microsoft.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: zhong jiang <zhongjiang@huawei.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by:
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Michal Hocko authored
Alice has reported the following UBSAN splat: UBSAN: Undefined behaviour in mm/memcontrol.c:661:17 signed integer overflow: -2147483644 - 2147483525 cannot be represented in type 'long int' CPU: 1 PID: 11758 Comm: mybibtex2filena Tainted: P O 4.9.25-gentoo #4 Hardware name: XXXXXX, BIOS YYYYYY Call Trace: dump_stack+0x59/0x87 ubsan_epilogue+0xe/0x40 handle_overflow+0xbb/0xf0 __ubsan_handle_sub_overflow+0x12/0x20 memcg_check_events.isra.36+0x223/0x360 mem_cgroup_commit_charge+0x55/0x140 wp_page_copy+0x34e/0xb80 do_wp_page+0x1e6/0x1300 handle_mm_fault+0x88b/0x1990 __do_page_fault+0x2de/0x8a0 do_page_fault+0x1a/0x20 error_code+0x67/0x6c The reason is that we subtract two signed types. Let's fix this by truly mimicing time_after and cast the result of the subtraction. Link: http://lkml.kernel.org/r/20170616150057.GQ30580@dhcp22.suse.czSigned-off-by:Alice Ferrazzi <alicef@gentoo.org> Signed-off-by:
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David Rientjes authored
A few hugetlb allocators loop while calling the page allocator and can potentially prevent rescheduling if the page allocator slowpath is not utilized. Conditionally schedule when large numbers of hugepages can be allocated. Anshuman: "Fixes a task which was getting hung while writing like 10000 hugepages (16MB on POWER8) into /proc/sys/vm/nr_hugepages." Link: http://lkml.kernel.org/r/alpine.DEB.2.10.1706091535300.66176@chino.kir.corp.google.comSigned-off-by:
Anshuman Khandual <khandual@linux.vnet.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by:
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Michal Hocko authored
Commit 394e31d2 ("mem-hotplug: alloc new page from a nearest neighbor node when mem-offline") has duplicated a large part of alloc_migrate_target with some hotplug specific special casing. To be more precise it tried to enfore the allocation from a different node than the original page. As a result the two function diverged in their shared logic, e.g. the hugetlb allocation strategy. Let's unify the two and express different NUMA requirements by the given nodemask. new_node_page will simply exclude the node it doesn't care about and alloc_migrate_target will use all the available nodes. alloc_migrate_target will then learn to migrate hugetlb pages more sanely and use preallocated pool when possible. Please note that alloc_migrate_target used to call alloc_page resp. alloc_pages_current so the memory policy of the current context which is quite strange when we consider that it is used in the context of alloc_contig_range which just tries to migrate pages which stand in the way. Link: http://lkml.kernel.org/r/20170608074553.22152-4-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
new_node_page will try to use the origin's next NUMA node as the migration destination for hugetlb pages. If such a node doesn't have any preallocated pool it falls back to __alloc_buddy_huge_page_no_mpol to allocate a surplus page instead. This is quite subotpimal for any configuration when hugetlb pages are no distributed to all NUMA nodes evenly. Say we have a hotplugable node 4 and spare hugetlb pages are node 0 /sys/devices/system/node/node0/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node1/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node2/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node3/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node4/hugepages/hugepages-2048kB/nr_hugepages:10000 /sys/devices/system/node/node5/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node6/hugepages/hugepages-2048kB/nr_hugepages:0 /sys/devices/system/node/node7/hugepages/hugepages-2048kB/nr_hugepages:0 Now we consume the whole pool on node 4 and try to offline this node. All the allocated pages should be moved to node0 which has enough preallocated pages to hold them. With the current implementation offlining very likely fails because hugetlb allocations during runtime are much less reliable. Fix this by reusing the nodemask which excludes migration source and try to find a first node which has a page in the preallocated pool first and fall back to __alloc_buddy_huge_page_no_mpol only when the whole pool is consumed. [akpm@linux-foundation.org: remove bogus arg from alloc_huge_page_nodemask() stub] Link: http://lkml.kernel.org/r/20170608074553.22152-3-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
new_node_page tries to allocate the target page on a different NUMA node than the source page. This makes sense in most cases during the hotplug because we are likely to offline the whole numa node. But there are cases where there are no other nodes to fallback (e.g. when offlining parts of the only existing node) and we have to fallback to allocating from the source node. The current code does that but it can be simplified by checking the nmask and updating it before we even try to allocate rather than special casing it. This patch shouldn't introduce any functional change. Link: http://lkml.kernel.org/r/20170608074553.22152-2-mhocko@kernel.orgSigned-off-by:
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Michal Hocko authored
movable_node kernel parameter allows making hotpluggable NUMA nodes to put all the hotplugable memory into movable zone which allows more or less reliable memory hotremove. At least this is the case for the NUMA nodes present during the boot (see find_zone_movable_pfns_for_nodes). This is not the case for the memory hotplug, though. echo online > /sys/devices/system/memory/memoryXYZ/state will default to a kernel zone (usually ZONE_NORMAL) unless the particular memblock is already in the movable zone range which is not the case normally when onlining the memory from the udev rule context for a freshly hotadded NUMA node. The only option currently is to have a special udev rule to echo online_movable to all memblocks belonging to such a node which is rather clumsy. Not to mention this is inconsistent as well because what ended up in the movable zone during the boot will end up in a kernel zone after hotremove & hotadd without special care. It would be nice to reuse memblock_is_hotpluggable but the runtime hotplug doesn't have that information available because the boot and hotplug paths are not shared and it would be really non trivial to make them use the same code path because the runtime hotplug doesn't play with the memblock allocator at all. Teach move_pfn_range that MMOP_ONLINE_KEEP can use the movable zone if movable_node is enabled and the range doesn't overlap with the existing normal zone. This should provide a reasonable default onlining strategy. Strictly speaking the semantic is not identical with the boot time initialization because find_zone_movable_pfns_for_nodes covers only the hotplugable range as described by the BIOS/FW. From my experience this is usually a full node though (except for Node0 which is special and never goes away completely). If this turns out to be a problem in the real life we can tweak the code to store hotplug flag into memblocks but let's keep this simple now. Link: http://lkml.kernel.org/r/20170612111227.GI7476@dhcp22.suse.czSigned-off-by:
Reza Arbab <arbab@linux.vnet.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Yasuaki Ishimatsu <yasu.isimatu@gmail.com> Cc: <qiuxishi@huawei.com> Cc: Kani Toshimitsu <toshi.kani@hpe.com> Cc: <slaoub@gmail.com> Cc: Joonsoo Kim <js1304@gmail.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Daniel Kiper <daniel.kiper@oracle.com> Cc: Igor Mammedov <imammedo@redhat.com> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Signed-off-by:
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Andy Shevchenko authored
Use __sysfs_match_string() helper instead of open coded variant. Link: http://lkml.kernel.org/r/20170609120835.22156-1-andriy.shevchenko@linux.intel.comSigned-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Reviewed-by:
Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by:
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Will Deacon authored
When migrating a transparent hugepage, migrate_misplaced_transhuge_page guards itself against a concurrent fastgup of the page by checking that the page count is equal to 2 before and after installing the new pmd. If the page count changes, then the pmd is reverted back to the original entry, however there is a small window where the new (possibly writable) pmd is installed and the underlying page could be written by userspace. Restoring the old pmd could therefore result in loss of data. This patch fixes the problem by freezing the page count whilst updating the page tables, which protects against a concurrent fastgup without the need to restore the old pmd in the failure case (since the page count can no longer change under our feet). Link: http://lkml.kernel.org/r/1497349722-6731-4-git-send-email-will.deacon@arm.comSigned-off-by:
Will Deacon <will.deacon@arm.com> Acked-by:
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Will Deacon authored
page_ref_freeze and page_ref_unfreeze are designed to be used as a pair, wrapping a critical section where struct pages can be modified without having to worry about consistency for a concurrent fast-GUP. Whilst page_ref_freeze has full barrier semantics due to its use of atomic_cmpxchg, page_ref_unfreeze is implemented using atomic_set, which doesn't provide any barrier semantics and allows the operation to be reordered with respect to page modifications in the critical section. This patch ensures that page_ref_unfreeze is ordered after any critical section updates, by invoking smp_mb() prior to the atomic_set. Link: http://lkml.kernel.org/r/1497349722-6731-3-git-send-email-will.deacon@arm.comSigned-off-by:
Steve Capper <steve.capper@arm.com> Acked-by:
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Dan Williams authored
The madvise policy for transparent huge pages is meant to avoid unwanted allocations of transparent huge pages. It allows a policy of disabling the extra memory pressure and effort to arrange for a huge page when it is not needed. DAX by definition never incurs this overhead since it is statically allocated. The policy choice makes even less sense for device-dax which tries to guarantee a given tlb-fault size. Specifically, the following setting: echo never > /sys/kernel/mm/transparent_hugepage/enabled ...violates that guarantee and silently disables all device-dax instances with a 2M or 1G alignment. So, let's avoid that non-obvious side effect by force enabling thp for dax mappings in all cases. It is worth noting that the reason this uses vma_is_dax(), and the resulting header include changes, is that previous attempts to add a VM_DAX flag were NAKd. Link: http://lkml.kernel.org/r/149739531127.20686.15813586620597484283.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
Dan Williams <dan.j.williams@intel.com> Reviewed-by:
Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Christoph Hellwig <hch@lst.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:
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Dan Williams authored
Turn the macro into a static inline and rewrite the condition checks for better readability in preparation for adding another condition. [ross.zwisler@linux.intel.com: fix logic to make conversion equivalent] [akpm@linux-foundation.org: resolve vs mm-make-pr_set_thp_disable-immediately-active.patch] [akpm@linux-foundation.org: include coredump.h for MMF_DISABLE_THP] Link: http://lkml.kernel.org/r/149739530612.20686.14760671150202647861.stgit@dwillia2-desk3.amr.corp.intel.comSigned-off-by:
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Steven Rostedt (VMware) authored
After enabling CONFIG_TRACE_ENUM_MAP_FILE (which will soon be renamed to CONFIG_TRACE_EVAL_MAP_FILE), I am able to examine the enums that have been evaluated: # cat /sys/kernel/debug/tracing/enum_map (which will soon be renamed to eval_map) And it showed some interesting results: [..] ZONE_MOVABLE 3 (oom) ZONE_NORMAL 2 (oom) ZONE_DMA32 1 (oom) ZONE_DMA 0 (oom) 3 3 (oom) 2 2 (oom) 1 1 (oom) COMPACT_PRIO_ASYNC 2 (oom) COMPACT_PRIO_SYNC_LIGHT 1 (oom) COMPACT_PRIO_SYNC_FULL 0 (oom) [..] ZONE_DMA 0 (vmscan) 3 3 (vmscan) 2 2 (vmscan) 1 1 (vmscan) COMPACT_PRIO_ASYNC 2 (vmscan) [..] ZONE_DMA 0 (kmem) 3 3 (kmem) 2 2 (kmem) 1 1 (kmem) COMPACT_PRIO_ASYNC 2 (kmem) [..] ZONE_DMA 0 (compaction) 3 3 (compaction) 2 2 (compaction) 1 1 (compaction) COMPACT_PRIO_ASYNC 2 (compaction) [..] The name within the parenthesis are the trace systems that the enum/eval maps are associated with. When there's a number evaluated to another number, that tells me that the TRACE_DEFINE_ENUM() was used on a #define and not an enum. As #defines get converted normally, they are not needed to be evaluated. Each of the above trace systems with the number to number evaluation included the file include/trace/events/mmflags.h which has: /* High-level compaction status feedback */ #define COMPACTION_FAILED 1 #define COMPACTION_WITHDRAWN 2 #define COMPACTION_PROGRESS 3 [..] #define COMPACTION_FEEDBACK \ EM(COMPACTION_FAILED, "failed") \ EM(COMPACTION_WITHDRAWN, "withdrawn") \ EMe(COMPACTION_PROGRESS, "progress") Which is still needed for the __print_symbolic() usage in the trace_event. But it is not needed to be evaluated. Removing the evaluation part removes the unnecessary evaluations of numbers to numbers. Link: http://lkml.kernel.org/r/20170615074944.7be9a647@gandalf.local.homeSigned-off-by:Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by:
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Liam R. Howlett authored
When the user specifies too many hugepages or an invalid default_hugepagesz the communication to the user is implicit in the allocation message. This patch adds a warning when the desired page count is not allocated and prints an error when the default_hugepagesz is invalid on boot. During boot hugepages will allocate until there is a fraction of the hugepage size left. That is, we allocate until either the request is satisfied or memory for the pages is exhausted. When memory for the pages is exhausted, it will most likely lead to the system failing with the OOM manager not finding enough (or anything) to kill (unless you're using really big hugepages in the order of 100s of MB or in the GBs). The user will most likely see the OOM messages much later in the boot sequence than the implicitly stated message. Worse yet, you may even get an OOM for each processor which causes many pages of OOMs on modern systems. Although these messages will be printed earlier than the OOM messages, at least giving the user errors and warnings will highlight the configuration as an issue. I'm trying to point the user in the right direction by providing a more robust statement of what is failing. During the sysctl or echo command, the user can check the results much easier than if the system hangs during boot and the scenario of having nothing to OOM for kernel memory is highly unlikely. Mike said: "Before sending out this patch, I asked Liam off list why he was doing it. Was it something he just thought would be useful? Or, was there some type of user situation/need. He said that he had been called in to assist on several occasions when a system OOMed during boot. In almost all of these situations, the user had grossly misconfigured huge pages. DB users want to pre-allocate just the right amount of huge pages, but sometimes they can be really off. In such situations, the huge page init code just allocates as many huge pages as it can and reports the number allocated. There is no indication that it quit allocating because it ran out of memory. Of course, a user could compare the number in the message to what they requested on the command line to determine if they got all the huge pages they requested. The thought was that it would be useful to at least flag this situation. That way, the user might be able to better relate the huge page allocation failure to the OOM. I'm not sure if the e-mail discussion made it obvious that this is something he has seen on several occasions. I see Michal's point that this will only flag the situation where someone configures huge pages very badly. And, a more extensive look at the situation of misconfiguring huge pages might be in order. But, this has happened on several occasions which led to the creation of this patch" [akpm@linux-foundation.org: reposition memfmt() to avoid forward declaration] Link: http://lkml.kernel.org/r/20170603005413.10380-1-Liam.Howlett@Oracle.comSigned-off-by:
Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: zhongjiang <zhongjiang@huawei.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by:
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