- 10 Jul, 2017 40 commits
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Ian Abbott authored
Correct these checkpatch.pl warnings: |WARNING: Block comments use * on subsequent lines |#34: FILE: include/linux/bug.h:34: |+/* Force a compilation error if condition is true, but also produce a |+ result (of value 0 and type size_t), so the expression can be used |WARNING: Block comments use a trailing */ on a separate line |#36: FILE: include/linux/bug.h:36: |+ aren't permitted). */ Link: http://lkml.kernel.org/r/20170525120316.24473-3-abbotti@mev.co.ukSigned-off-by:
Ian Abbott <abbotti@mev.co.uk> Acked-by:
Michal Nazarewicz <mina86@mina86.com> Cc: Kees Cook <keescook@chromium.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Jakub Kicinski <jakub.kicinski@netronome.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Ian Abbott authored
This series of patches splits BUILD_BUG related macros out of "include/linux/bug.h" into new file "include/linux/build_bug.h" (patch 5), and changes the pointer type checking in the `container_of()` macro to deal with pointers of array type better (patch 6). Patches 1 to 4 are prerequisites. Patches 2, 3, 4, and 5 have been inserted since the previous version of this patch series. Patch 6 here corresponds to v3 and v4's patch 2. Patch 1 was a prerequisite in v3 of this series to avoid a lot of warnings when <linux/bug.h> was included by <linux/kernel.h>. That is no longer relevant for v5 of the series, but I left it in because it was acked by a Arnd Bergmann and Michal Nazarewicz. Patches 2, 3, and 4 are some checkpatch clean-ups on "include/linux/bug.h" before splitting out the BUILD_BUG stuff in patch 5. Patch 5 splits the BUILD_BUG related macros out of "include/linux/bug.h" into new file "include/linux/build_bug.h" because including <linux/bug.h> in "include/linux/kernel.h" would result in build failures due to circular dependencies. Patch 6 changes the pointer type checking by `container_of()` to avoid some incompatible pointer warnings when the dereferenced pointer has array type. 1) asm-generic/bug.h: declare struct pt_regs; before function prototype 2) linux/bug.h: correct formatting of block comment 3) linux/bug.h: correct "(foo*)" should be "(foo *)" 4) linux/bug.h: correct "space required before that '-'" 5) bug: split BUILD_BUG stuff out into <linux/build_bug.h> 6) kernel.h: handle pointers to arrays better in container_of() This patch (of 6): The declaration of `__warn()` has `struct pt_regs *regs` as one of its parameters. This can result in compiler warnings if `struct regs` is not already declared. Add an empty declaration of `struct pt_regs` to avoid the warnings. Link: http://lkml.kernel.org/r/20170525120316.24473-2-abbotti@mev.co.ukSigned-off-by:
Arnd Bergmann <arnd@arndb.de> Acked-by:
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Heiner Kallweit authored
The code can be much simplified by switching to ida_simple_get/remove. Link: http://lkml.kernel.org/r/8d1cc9f7-5115-c9dc-028e-c0770b6bfe1f@gmail.comSigned-off-by:
Heiner Kallweit <hkallweit1@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Will Deacon authored
FRV supports 64-bit cmpxchg, which is provided by the arch code as __cmpxchg_64 and subsequently used to implement atomic64_cmpxchg. This patch hooks up the generic cmpxchg64 API using the same function, which also provides default definitions of the relaxed, acquire and release variants. This fixes the build when COMPILE_TEST=y and IOMMU_IO_PGTABLE_LPAE=y. Link: http://lkml.kernel.org/r/1499084670-6996-1-git-send-email-will.deacon@arm.comSigned-off-by:
Will Deacon <will.deacon@arm.com> Reported-by:
kbuild test robot <fengguang.wu@intel.com> Cc: Joerg Roedel <joro@8bytes.org> Cc: Robin Murphy <robin.murphy@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: David Howells <dhowells@redhat.com> Signed-off-by:
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Tobias Klauser authored
The arch uses a verbatim copy of the asm-generic version and does not add any own implementations to the header, so use asm-generic/fb.h instead of duplicating code. Link: http://lkml.kernel.org/r/20170517083307.1697-1-tklauser@distanz.chSigned-off-by:
Tobias Klauser <tklauser@distanz.ch> Reviewed-by:
David Howells <dhowells@redhat.com> Signed-off-by:
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Tobias Klauser authored
frv's asm/device.h is merely including asm-generic/device.h. Thus, the arch specific header can be omitted and the generic header can be used directly. Link: http://lkml.kernel.org/r/20170517124915.26904-1-tklauser@distanz.chSigned-off-by:
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Colin Ian King authored
The helper function get_wild_bug_type() does not need to be in global scope, so make it static. Cleans up sparse warning: "symbol 'get_wild_bug_type' was not declared. Should it be static?" Link: http://lkml.kernel.org/r/20170622090049.10658-1-colin.king@canonical.comSigned-off-by:
Colin Ian King <colin.king@canonical.com> Acked-by:
Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Signed-off-by:
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Joonsoo Kim authored
They return positive value, that is, true, if non-zero value is found. Rename them to reduce confusion. Link: http://lkml.kernel.org/r/20170516012350.GA16015@js1304-desktopSigned-off-by:
Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by:
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Andrey Ryabinin authored
KASAN doesn't happen work with memory hotplug because hotplugged memory doesn't have any shadow memory. So any access to hotplugged memory would cause a crash on shadow check. Use memory hotplug notifier to allocate and map shadow memory when the hotplugged memory is going online and free shadow after the memory offlined. Link: http://lkml.kernel.org/r/20170601162338.23540-4-aryabinin@virtuozzo.comSigned-off-by:
Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Potapenko <glider@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Ingo Molnar <mingo@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Will Deacon <will.deacon@arm.com> Signed-off-by:
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Andrey Ryabinin authored
We used to read several bytes of the shadow memory in advance. Therefore additional shadow memory mapped to prevent crash if speculative load would happen near the end of the mapped shadow memory. Now we don't have such speculative loads, so we no longer need to map additional shadow memory. Link: http://lkml.kernel.org/r/20170601162338.23540-3-aryabinin@virtuozzo.comSigned-off-by:
Mark Rutland <mark.rutland@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by:
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Andrey Ryabinin authored
We used to read several bytes of the shadow memory in advance. Therefore additional shadow memory mapped to prevent crash if speculative load would happen near the end of the mapped shadow memory. Now we don't have such speculative loads, so we no longer need to map additional shadow memory. Link: http://lkml.kernel.org/r/20170601162338.23540-2-aryabinin@virtuozzo.comSigned-off-by:
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Andrey Ryabinin authored
For some unaligned memory accesses we have to check additional byte of the shadow memory. Currently we load that byte speculatively to have only single load + branch on the optimistic fast path. However, this approach has some downsides: - It's unaligned access, so this prevents porting KASAN on architectures which doesn't support unaligned accesses. - We have to map additional shadow page to prevent crash if speculative load happens near the end of the mapped memory. This would significantly complicate upcoming memory hotplug support. I wasn't able to notice any performance degradation with this patch. So these speculative loads is just a pain with no gain, let's remove them. Link: http://lkml.kernel.org/r/20170601162338.23540-1-aryabinin@virtuozzo.comSigned-off-by:
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Joonsoo Kim authored
There is missing optimization in zero_p4d_populate() that can save some memory when mapping zero shadow. Implement it like as others. Link: http://lkml.kernel.org/r/1494829255-23946-1-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by:
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Jerome Marchand authored
Commit 40f9fb8c ("mm/zsmalloc: support allocating obj with size of ZS_MAX_ALLOC_SIZE") fixes a size calculation error that prevented zsmalloc to allocate an object of the maximal size (ZS_MAX_ALLOC_SIZE). I think however the fix is unneededly complicated. This patch replaces the dynamic calculation of zs_size_classes at init time by a compile time calculation that uses the DIV_ROUND_UP() macro already used in get_size_class_index(). [akpm@linux-foundation.org: use min_t] Link: http://lkml.kernel.org/r/20170630114859.1979-1-jmarchan@redhat.comSigned-off-by:
Jerome Marchand <jmarchan@redhat.com> Acked-by:
Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Mahendran Ganesh <opensource.ganesh@gmail.com> Signed-off-by:
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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:
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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:
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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