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2017-02-22userfaultfd: document _IOR/_IOWAndrea Arcangeli2-1/+15
Patch series "userfaultfd tmpfs/hugetlbfs/non-cooperative", v2 These userfaultfd features are finished and are ready for larger exposure in -mm and upstream merging. 1) tmpfs non present userfault 2) hugetlbfs non present userfault 3) non cooperative userfault for fork/madvise/mremap qemu development code is already exercising 2) and container postcopy live migration needs 3). 1) is not currently used but there's a self test and we know some qemu user for various reasons uses tmpfs as backing for KVM so it'll need it too to use postcopy live migration with tmpfs memory. All review feedback from the previous submit has been handled and the fixes are included. There's no outstanding issue AFIK. Upstream code just did a s/fe/vmf/ conversion in the page faults and this has been converted as well incrementally. In addition to the previous submits, this also wakes up stuck userfaults during UFFDIO_UNREGISTER. The non cooperative testcase actually reproduced this problem by getting stuck instead of quitting clean in some rare case as it could call UFFDIO_UNREGISTER while some userfault could be still in flight. The other option would have been to keep leaving it up to userland to serialize itself and to patch the testcase instead but the wakeup during unregister I think is preferable. David also asked the UFFD_FEATURE_MISSING_HUGETLBFS and UFFD_FEATURE_MISSING_SHMEM feature flags to be added so QEMU can avoid to probe if the hugetlbfs/shmem missing support is available by calling UFFDIO_REGISTER. QEMU already checks HUGETLBFS_MAGIC with fstatfs so if UFFD_FEATURE_MISSING_HUGETLBFS is also set, it knows UFFDIO_REGISTER will succeed (or if it fails, it's for some other more concerning reason). There's no reason to worry about adding too many feature flags. There are 64 available and worst case we've to bump the API if someday we're really going to run out of them. The round-trip network latency of hugetlbfs userfaults during postcopy live migration is still of the order of dozen milliseconds on 10GBit if at 2MB hugepage granularity so it's working perfectly and it should provide for higher bandwidth or lower CPU usage (which makes it interesting to add an option in the future to support THP granularity too for anonymous memory, UFFDIO_COPY would then have to create THP if alignment/len allows for it). 1GB hugetlbfs granularity will require big changes in hugetlbfs to work so it's deferred for later. This patch (of 42): This adds proper documentation (inline) to avoid the risk of further misunderstandings about the semantics of _IOW/_IOR and it also reminds whoever will bump the UFFDIO_API in the future, to change the two ioctl to _IOW. This was found while implementing strace support for those ioctl, otherwise we could have never found it by just reviewing kernel code and testing it. _IOC_READ or _IOC_WRITE alters nothing but the ioctl number itself, so it's only worth fixing if the UFFDIO_API is bumped someday. Link: http://lkml.kernel.org/r/20161216144821.5183-2-aarcange@redhat.com Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: "Dmitry V. Levin" <ldv@altlinux.org> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22oom, trace: add compaction retry tracepointMichal Hocko3-6/+81
Higher order requests oom debugging is currently quite hard. We do have some compaction points which can tell us how the compaction is operating but there is no trace point to tell us about compaction retry logic. This patch adds a one which will have the following format bash-3126 [001] .... 1498.220001: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=withdrawn retries=0 max_retries=16 should_retry=0 we can see that the order 9 request is not retried even though we are in the highest compaction priority mode becase the last compaction attempt was withdrawn. This means that compaction_zonelist_suitable must have returned false and there is no suitable zone to compact for this request and so no need to retry further. another example would be <...>-3137 [001] .... 81.501689: compact_retry: order=9 priority=COMPACT_PRIO_SYNC_LIGHT compaction_result=failed retries=0 max_retries=16 should_retry=0 in this case the order-9 compaction failed to find any suitable block. We do not retry anymore because this is a costly request and those do not go below COMPACT_PRIO_SYNC_LIGHT priority. Link: http://lkml.kernel.org/r/20161220130135.15719-4-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22oom, trace: add oom detection tracepointsMichal Hocko2-2/+50
should_reclaim_retry is the central decision point for declaring the OOM. It might be really useful to expose data used for this decision making when debugging an unexpected oom situations. Say we have an OOM report: [ 52.264001] mem_eater invoked oom-killer: gfp_mask=0x24280ca(GFP_HIGHUSER_MOVABLE|__GFP_ZERO), nodemask=0, order=0, oom_score_adj=0 [ 52.267549] CPU: 3 PID: 3148 Comm: mem_eater Tainted: G W 4.8.0-oomtrace3-00006-gb21338b386d2 #1024 Now we can check the tracepoint data to see how we have ended up in this situation: mem_eater-3148 [003] .... 52.432801: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11134 min_wmark=11084 no_progress_loops=1 wmark_check=1 mem_eater-3148 [003] .... 52.433269: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11103 min_wmark=11084 no_progress_loops=1 wmark_check=1 mem_eater-3148 [003] .... 52.433712: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11100 min_wmark=11084 no_progress_loops=2 wmark_check=1 mem_eater-3148 [003] .... 52.434067: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11097 min_wmark=11084 no_progress_loops=3 wmark_check=1 mem_eater-3148 [003] .... 52.434414: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11094 min_wmark=11084 no_progress_loops=4 wmark_check=1 mem_eater-3148 [003] .... 52.434761: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11091 min_wmark=11084 no_progress_loops=5 wmark_check=1 mem_eater-3148 [003] .... 52.435108: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11087 min_wmark=11084 no_progress_loops=6 wmark_check=1 mem_eater-3148 [003] .... 52.435478: reclaim_retry_zone: node=0 zone=DMA32 order=0 reclaimable=51 available=11084 min_wmark=11084 no_progress_loops=7 wmark_check=0 mem_eater-3148 [003] .... 52.435478: reclaim_retry_zone: node=0 zone=DMA order=0 reclaimable=0 available=1126 min_wmark=179 no_progress_loops=7 wmark_check=0 The above shows that we can quickly deduce that the reclaim stopped making any progress (see no_progress_loops increased in each round) and while there were still some 51 reclaimable pages they couldn't be dropped for some reason (vmscan trace points would tell us more about that part). available will represent reclaimable + free_pages scaled down per no_progress_loops factor. This is essentially an optimistic estimate of how much memory we would have when reclaiming everything. This can be compared to min_wmark to get a rought idea but the wmark_check tells the result of the watermark check which is more precise (includes lowmem reserves, considers the order etc.). As we can see no zone is eligible in the end and that is why we have triggered the oom in this situation. Please note that higher order requests might fail on the wmark_check even when there is much more memory available than min_wmark - e.g. when the memory is fragmented. A follow up tracepoint will help to debug those situations. Link: http://lkml.kernel.org/r/20161220130135.15719-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, trace: extract COMPACTION_STATUS and ZONE_TYPE to a common headerMichal Hocko2-57/+67
COMPACTION_STATUS resp. ZONE_TYPE are currently used to translate enum compact_result resp. struct zone index into their symbolic names for an easier post processing. The follow up patch would like to reuse this as well. The code involves some preprocessor black magic which is better not duplicated elsewhere so move it to a common mm tracing relate header. Link: http://lkml.kernel.org/r/20161220130135.15719-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: David Rientjes <rientjes@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm/vmalloc.c: use rb_entry_safeGeliang Tang1-1/+1
Use rb_entry_safe() instead of open-coding it. Link: http://lkml.kernel.org/r/81bb9820e5b9e4a1c596b3e76f88abf8c4a76cb0.1482221947.git.geliangtang@gmail.com Signed-off-by: Geliang Tang <geliangtang@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, page_alloc: avoid page_to_pfn() when merging buddiesVlastimil Babka2-6/+6
On architectures that allow memory holes, page_is_buddy() has to perform page_to_pfn() to check for the memory hole. After the previous patch, we have the pfn already available in __free_one_page(), which is the only caller of page_is_buddy(), so move the check there and avoid page_to_pfn(). Link: http://lkml.kernel.org/r/20161216120009.20064-2-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, page_alloc: don't convert pfn to idx when mergingVlastimil Babka3-23/+20
In __free_one_page() we do the buddy merging arithmetics on "page/buddy index", which is just the lower MAX_ORDER bits of pfn. The operations we do that affect the higher bits are bitwise AND and subtraction (in that order), where the final result will be the same with the higher bits left unmasked, as long as these bits are equal for both buddies - which must be true by the definition of a buddy. We can therefore use pfn's directly instead of "index" and skip the zeroing of >MAX_ORDER bits. This can help a bit by itself, although compiler might be smart enough already. It also helps the next patch to avoid page_to_pfn() for memory hole checks. Link: http://lkml.kernel.org/r/20161216120009.20064-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Mel Gorman <mgorman@techsingularity.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm: throttle show_mem() from warn_alloc()Michal Hocko1-11/+18
Tetsuo has been stressing OOM killer path with many parallel allocation requests when he has noticed that it is not all that hard to swamp kernel logs with warn_alloc messages caused by allocation stalls. Even though the allocation stall message is triggered only once in 10s there might be many different tasks hitting it roughly around the same time. A big part of the output is show_mem() which can generate a lot of output even on a small machines. There is no reason to show the state of memory counter for each allocation stall, especially when multiple of them are reported in a short time period. Chances are that not much has changed since the last report. This patch simply rate limits show_mem called from warn_alloc to only dump something once per second. This should be enough to give us a clue why an allocation might be stalling while burst of warnings will not swamp log with too much data. While we are at it, extract all the show_mem related handling (filters) into a separate function warn_alloc_show_mem. This will make the code cleaner and as a bonus point we can distinguish which part of warn_alloc got throttled due to rate limiting as ___ratelimit dumps the caller. [akpm@linux-foundation.org: reduce scope of the ratelimit_states] Link: http://lkml.kernel.org/r/20161215101510.9030-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22tmpfs: change shmem_mapping() to test shmem_aopsHugh Dickins1-4/+1
Callers of shmem_mapping() are interested in whether the mapping is swap backed - except for uprobes, which is interested in whether it should use shmem_read_mapping_page(). All these callers are better served by a shmem_mapping() which checks for shmem_aops, than the current version which goes through several indirections to find where the inode lives - and has the surprising effect that a private mmap of /dev/zero satisfies both vma_is_anonymous() and shmem_mapping(), when that device node is on devtmpfs. I don't think anything in the tree suffers from that surprise, but it caught me out, and is better fixed. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1612052148530.13021@eggly.anvils Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slub: make sysfs directories for memcg sub-caches optionalTejun Heo3-2/+46
SLUB creates a per-cache directory under /sys/kernel/slab which hosts a bunch of debug files. Usually, there aren't that many caches on a system and this doesn't really matter; however, if memcg is in use, each cache can have per-cgroup sub-caches. SLUB creates the same directories for these sub-caches under /sys/kernel/slab/$CACHE/cgroup. Unfortunately, because there can be a lot of cgroups, active or draining, the product of the numbers of caches, cgroups and files in each directory can reach a very high number - hundreds of thousands is commonplace. Millions and beyond aren't difficult to reach either. What's under /sys/kernel/slab is primarily for debugging and the information and control on the a root cache already cover its sub-caches. While having a separate directory for each sub-cache can be helpful for development, it doesn't make much sense to pay this amount of overhead by default. This patch introduces a boot parameter slub_memcg_sysfs which determines whether to create sysfs directories for per-memcg sub-caches. It also adds CONFIG_SLUB_MEMCG_SYSFS_ON which determines the boot parameter's default value and defaults to 0. [akpm@linux-foundation.org: kset_unregister(NULL) is legal] Link: http://lkml.kernel.org/r/20170204145203.GB26958@mtj.duckdns.org Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: use memcg_kmem_cache_wq for slab destruction operationsTejun Heo3-9/+10
If there's contention on slab_mutex, queueing the per-cache destruction work item on the system_wq can unnecessarily create and tie up a lot of kworkers. Rename memcg_kmem_cache_create_wq to memcg_kmem_cache_wq and make it global and use that workqueue for the destruction work items too. While at it, convert the workqueue from an unbound workqueue to a per-cpu one with concurrency limited to 1. It's generally preferable to use per-cpu workqueues and concurrency limit of 1 is safe enough. This is suggested by Joonsoo Kim. Link: http://lkml.kernel.org/r/20170117235411.9408-11-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov@tarantool.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: remove slub sysfs interface files early for empty memcg cachesTejun Heo1-2/+23
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. Each cache has a number of sysfs interface files under /sys/kernel/slab. On a system with a lot of memory and transient memcgs, the number of interface files which have to be removed once memory reclaim kicks in can reach millions. Link: http://lkml.kernel.org/r/20170117235411.9408-10-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: remove synchronous synchronize_sched() from memcg cache deactivation pathTejun Heo4-4/+76
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. slub uses synchronize_sched() to deactivate a memcg cache. synchronize_sched() is an expensive and slow operation and doesn't scale when a huge number of caches are destroyed back-to-back. While there used to be a simple batching mechanism, the batching was too restricted to be helpful. This patch implements slab_deactivate_memcg_cache_rcu_sched() which slub can use to schedule sched RCU callback instead of performing synchronize_sched() synchronously while holding cgroup_mutex. While this adds online cpus, mems and slab_mutex operations, operating on these locks back-to-back from the same kworker, which is what's gonna happen when there are many to deactivate, isn't expensive at all and this gets rid of the scalability problem completely. Link: http://lkml.kernel.org/r/20170117235411.9408-9-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: introduce __kmemcg_cache_deactivate()Tejun Heo5-23/+36
__kmem_cache_shrink() is called with %true @deactivate only for memcg caches. Remove @deactivate from __kmem_cache_shrink() and introduce __kmemcg_cache_deactivate() instead. Each memcg-supporting allocator should implement it and it should deactivate and drain the cache. This is to allow memcg cache deactivation behavior to further deviate from simple shrinking without messing up __kmem_cache_shrink(). This is pure reorganization and doesn't introduce any observable behavior changes. v2: Dropped unnecessary ifdef in mm/slab.h as suggested by Vladimir. Link: http://lkml.kernel.org/r/20170117235411.9408-8-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: implement slab_root_caches listTejun Heo4-25/+53
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. slab_caches currently lists all caches including root and memcg ones. This is the only data structure which lists the root caches and iterating root caches can only be done by walking the list while skipping over memcg caches. As there can be a huge number of memcg caches, this can become very expensive. This also can make /proc/slabinfo behave very badly. seq_file processes reads in 4k chunks and seeks to the previous Nth position on slab_caches list to resume after each chunk. With a lot of memcg cache churns on the list, reading /proc/slabinfo can become very slow and its content often ends up with duplicate and/or missing entries. This patch adds a new list slab_root_caches which lists only the root caches. When memcg is not enabled, it becomes just an alias of slab_caches. memcg specific list operations are collected into memcg_[un]link_cache(). Link: http://lkml.kernel.org/r/20170117235411.9408-7-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov@tarantool.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: link memcg kmem_caches on their associated memory cgroupTejun Heo5-10/+40
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. While a memcg kmem_cache is listed on its root cache's ->children list, there is no direct way to iterate all kmem_caches which are assocaited with a memory cgroup. The only way to iterate them is walking all caches while filtering out caches which don't match, which would be most of them. This makes memcg destruction operations O(N^2) where N is the total number of slab caches which can be huge. This combined with the synchronous RCU operations can tie up a CPU and affect the whole machine for many hours when memory reclaim triggers offlining and destruction of the stale memcgs. This patch adds mem_cgroup->kmem_caches list which goes through memcg_cache_params->kmem_caches_node of all kmem_caches which are associated with the memcg. All memcg specific iterations, including stat file access, are updated to use the new list instead. Link: http://lkml.kernel.org/r/20170117235411.9408-6-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: reorganize memcg_cache_paramsTejun Heo3-24/+40
We're going to change how memcg caches are iterated. In preparation, clean up and reorganize memcg_cache_params. * The shared ->list is replaced by ->children in root and ->children_node in children. * ->is_root_cache is removed. Instead ->root_cache is moved out of the child union and now used by both root and children. NULL indicates root cache. Non-NULL a memcg one. This patch doesn't cause any observable behavior changes. Link: http://lkml.kernel.org/r/20170117235411.9408-5-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slab: remove synchronous rcu_barrier() call in memcg cache release pathTejun Heo1-42/+60
With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. SLAB_DESTORY_BY_RCU caches need to flush all RCU operations before destruction because slab pages are freed through RCU and they need to be able to dereference the associated kmem_cache. Currently, it's done synchronously with rcu_barrier(). As rcu_barrier() is expensive time-wise, slab implements a batching mechanism so that rcu_barrier() can be done for multiple caches at the same time. Unfortunately, the rcu_barrier() is in synchronous path which is called while holding cgroup_mutex and the batching is too limited to be actually helpful. This patch updates the cache release path so that the batching is asynchronous and global. All SLAB_DESTORY_BY_RCU caches are queued globally and a work item consumes the list. The work item calls rcu_barrier() only once for all caches that are currently queued. * release_caches() is removed and shutdown_cache() now either directly release the cache or schedules a RCU callback to do that. This makes the cache inaccessible once shutdown_cache() is called and makes it impossible for shutdown_memcg_caches() to do memcg-specific cleanups afterwards. Move memcg-specific part into a helper, unlink_memcg_cache(), and make shutdown_cache() call it directly. Link: http://lkml.kernel.org/r/20170117235411.9408-4-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Acked-by: Vladimir Davydov <vdavydov@tarantool.org> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slub: separate out sysfs_slab_release() from sysfs_slab_remove()Tejun Heo3-5/+13
Separate out slub sysfs removal and release, and call the former earlier from __kmem_cache_shutdown(). There's no reason to defer sysfs removal through RCU and this will later allow us to remove sysfs files way earlier during memory cgroup offline instead of release. Link: http://lkml.kernel.org/r/20170117235411.9408-3-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22Revert "slub: move synchronize_sched out of slab_mutex on shrink"Tejun Heo5-31/+23
Patch series "slab: make memcg slab destruction scalable", v3. With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. I've seen machines which end up with hundred thousands of caches and many millions of kernfs_nodes. The current code is O(N^2) on the total number of caches and has synchronous rcu_barrier() and synchronize_sched() in cgroup offline / release path which is executed while holding cgroup_mutex. Combined, this leads to very expensive and slow cache destruction operations which can easily keep running for half a day. This also messes up /proc/slabinfo along with other cache iterating operations. seq_file operates on 4k chunks and on each 4k boundary tries to seek to the last position in the list. With a huge number of caches on the list, this becomes very slow and very prone to the list content changing underneath it leading to a lot of missing and/or duplicate entries. This patchset addresses the scalability problem. * Add root and per-memcg lists. Update each user to use the appropriate list. * Make rcu_barrier() for SLAB_DESTROY_BY_RCU caches globally batched and asynchronous. * For dying empty slub caches, remove the sysfs files after deactivation so that we don't end up with millions of sysfs files without any useful information on them. This patchset contains the following nine patches. 0001-Revert-slub-move-synchronize_sched-out-of-slab_mutex.patch 0002-slub-separate-out-sysfs_slab_release-from-sysfs_slab.patch 0003-slab-remove-synchronous-rcu_barrier-call-in-memcg-ca.patch 0004-slab-reorganize-memcg_cache_params.patch 0005-slab-link-memcg-kmem_caches-on-their-associated-memo.patch 0006-slab-implement-slab_root_caches-list.patch 0007-slab-introduce-__kmemcg_cache_deactivate.patch 0008-slab-remove-synchronous-synchronize_sched-from-memcg.patch 0009-slab-remove-slub-sysfs-interface-files-early-for-emp.patch 0010-slab-use-memcg_kmem_cache_wq-for-slab-destruction-op.patch 0001 reverts an existing optimization to prepare for the following changes. 0002 is a prep patch. 0003 makes rcu_barrier() in release path batched and asynchronous. 0004-0006 separate out the lists. 0007-0008 replace synchronize_sched() in slub destruction path with call_rcu_sched(). 0009 removes sysfs files early for empty dying caches. 0010 makes destruction work items use a workqueue with limited concurrency. This patch (of 10): Revert 89e364db71fb5e ("slub: move synchronize_sched out of slab_mutex on shrink"). With kmem cgroup support enabled, kmem_caches can be created and destroyed frequently and a great number of near empty kmem_caches can accumulate if there are a lot of transient cgroups and the system is not under memory pressure. When memory reclaim starts under such conditions, it can lead to consecutive deactivation and destruction of many kmem_caches, easily hundreds of thousands on moderately large systems, exposing scalability issues in the current slab management code. This is one of the patches to address the issue. Moving synchronize_sched() out of slab_mutex isn't enough as it's still inside cgroup_mutex. The whole deactivation / release path will be updated to avoid all synchronous RCU operations. Revert this insufficient optimization in preparation to ease future changes. Link: http://lkml.kernel.org/r/20170117235411.9408-2-tj@kernel.org Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Jay Vana <jsvana@fb.com> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, slab: rename kmalloc-node cache to kmalloc-<size>Vlastimil Babka3-5/+9
SLAB as part of its bootstrap pre-creates one kmalloc cache that can fit the kmem_cache_node management structure, and puts it into the generic kmalloc cache array (e.g. for 128b objects). The name of this cache is "kmalloc-node", which is confusing for readers of /proc/slabinfo as the cache is used for generic allocations (and not just the kmem_cache_node struct) and it appears as the kmalloc-128 cache is missing. An easy solution is to use the kmalloc-<size> name when pre-creating the cache, which we can get from the kmalloc_info array. Example /proc/slabinfo before the patch: ... kmalloc-256 1647 1984 256 16 1 : tunables 120 60 8 : slabdata 124 124 828 kmalloc-192 1974 1974 192 21 1 : tunables 120 60 8 : slabdata 94 94 133 kmalloc-96 1332 1344 128 32 1 : tunables 120 60 8 : slabdata 42 42 219 kmalloc-64 2505 5952 64 64 1 : tunables 120 60 8 : slabdata 93 93 715 kmalloc-32 4278 4464 32 124 1 : tunables 120 60 8 : slabdata 36 36 346 kmalloc-node 1352 1376 128 32 1 : tunables 120 60 8 : slabdata 43 43 53 kmem_cache 132 147 192 21 1 : tunables 120 60 8 : slabdata 7 7 0 After the patch: ... kmalloc-256 1672 2160 256 16 1 : tunables 120 60 8 : slabdata 135 135 807 kmalloc-192 1992 2016 192 21 1 : tunables 120 60 8 : slabdata 96 96 203 kmalloc-96 1159 1184 128 32 1 : tunables 120 60 8 : slabdata 37 37 116 kmalloc-64 2561 4864 64 64 1 : tunables 120 60 8 : slabdata 76 76 785 kmalloc-32 4253 4340 32 124 1 : tunables 120 60 8 : slabdata 35 35 270 kmalloc-128 1256 1280 128 32 1 : tunables 120 60 8 : slabdata 40 40 39 kmem_cache 125 147 192 21 1 : tunables 120 60 8 : slabdata 7 7 0 [vbabka@suse.cz: export the whole kmalloc_info structure instead of just a name accessor, per Christoph Lameter] Link: http://lkml.kernel.org/r/54e80303-b814-4232-66d4-95b34d3eb9d0@suse.cz Link: http://lkml.kernel.org/r/20170203181008.24898-1-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm/slub: add a dump_stack() to the unexpected GFP checkBorislav Petkov1-0/+1
We wish to know who is doing such a thing. slab.c does this. Link: http://lkml.kernel.org/r/20170116091643.15260-1-bp@alien8.de Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22slub: do not merge cache if slub_debug contains a never-merge flagGrygorii Maistrenko1-1/+4
In case CONFIG_SLUB_DEBUG_ON=n, find_mergeable() gets debug features from commandline but never checks if there are features from the SLAB_NEVER_MERGE set. As a result selected by slub_debug caches are always mergeable if they have been created without a custom constructor set or without one of the SLAB_* debug features on. This moves the SLAB_NEVER_MERGE check below the flags update from commandline to make sure it won't merge the slab cache if one of the debug features is on. Link: http://lkml.kernel.org/r/20170101124451.GA4740@lp-laptop-d Signed-off-by: Grygorii Maistrenko <grygoriimkd@gmail.com> Reviewed-by: Pekka Enberg <penberg@kernel.org> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22kernel/watchdog.c: do not hardcode CPU 0 as the initial threadPrarit Bhargava1-10/+15
When CONFIG_BOOTPARAM_HOTPLUG_CPU0 is enabled, the socket containing the boot cpu can be replaced. During the hot add event, the message NMI watchdog: enabled on all CPUs, permanently consumes one hw-PMU counter. is output implying that the NMI watchdog was disabled at some point. This is not the case and the message has caused confusion for users of systems that support the removal of the boot cpu socket. The watchdog code is coded to assume that cpu 0 is always the first cpu to initialize the watchdog, and the last to stop its watchdog thread. That is not the case for initializing if cpu 0 has been removed and added. The removal case has never been correct because the smpboot code will remove the watchdog threads starting with the lowest cpu number. This patch adds watchdog_cpus to track the number of cpus with active NMI watchdog threads so that the first and last thread can be used to set and clear the value of firstcpu_err. firstcpu_err is set when the first watchdog thread is enabled, and cleared when the last watchdog thread is disabled. Link: http://lkml.kernel.org/r/1480425321-32296-1-git-send-email-prarit@redhat.com Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: Don Zickus <dzickus@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Tejun Heo <tj@kernel.org> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Andi Kleen <ak@linux.intel.com> Cc: Joshua Hunt <johunt@akamai.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Babu Moger <babu.moger@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-229p: fix a potential acl leakCong Wang1-0/+2
posix_acl_update_mode() could possibly clear 'acl', if so we leak the memory pointed by 'acl'. Save this pointer before calling posix_acl_update_mode() and release the memory if 'acl' really gets cleared. Link: http://lkml.kernel.org/r/1486678332-2430-1-git-send-email-xiyou.wangcong@gmail.com Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Reported-by: Mark Salyzyn <salyzyn@android.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Greg Kurz <groug@kaod.org> Cc: Eric Van Hensbergen <ericvh@gmail.com> Cc: Ron Minnich <rminnich@sandia.gov> Cc: Latchesar Ionkov <lucho@ionkov.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22block: use for_each_thread() in sys_ioprio_set()/sys_ioprio_get()Tetsuo Handa1-4/+4
IOPRIO_WHO_USER case in sys_ioprio_set()/sys_ioprio_get() are using while_each_thread(), which is unsafe under RCU lock according to commit 0c740d0afc3bff0a ("introduce for_each_thread() to replace the buggy while_each_thread()"). Use for_each_thread() (via for_each_process_thread()) which is safe under RCU lock. Link: http://lkml.kernel.org/r/201702011947.DBD56740.OMVHOLOtSJFFFQ@I-love.SAKURA.ne.jp Link: http://lkml.kernel.org/r/1486041779-4401-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22parisc: use generic current.hDavidlohr Bueso2-15/+1
Given that the arch does not add its own implementations, simply use the asm-generic/current.h (generic-y) header instead of duplicating code. Link: http://lkml.kernel.org/r/1485992878-4780-4-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22ocfs2: fix deadlock issue when taking inode lock at vfs entry pointsEric Ren2-29/+58
Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") results in a deadlock, as the author "Tariq Saeed" realized shortly after the patch was merged. The discussion happened here https://oss.oracle.com/pipermail/ocfs2-devel/2015-September/011085.html The reason why taking cluster inode lock at vfs entry points opens up a self deadlock window, is explained in the previous patch of this series. So far, we have seen two different code paths that have this issue. 1. do_sys_open may_open inode_permission ocfs2_permission ocfs2_inode_lock() <=== take PR generic_permission get_acl ocfs2_iop_get_acl ocfs2_inode_lock() <=== take PR 2. fchmod|fchmodat chmod_common notify_change ocfs2_setattr <=== take EX posix_acl_chmod get_acl ocfs2_iop_get_acl <=== take PR ocfs2_iop_set_acl <=== take EX Fixes them by adding the tracking logic (in the previous patch) for these funcs above, ocfs2_permission(), ocfs2_iop_[set|get]_acl(), ocfs2_setattr(). Link: http://lkml.kernel.org/r/20170117100948.11657-3-zren@suse.com Signed-off-by: Eric Ren <zren@suse.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22ocfs2/dlmglue: prepare tracking logic to avoid recursive cluster lockEric Ren3-3/+121
We are in the situation that we have to avoid recursive cluster locking, but there is no way to check if a cluster lock has been taken by a precess already. Mostly, we can avoid recursive locking by writing code carefully. However, we found that it's very hard to handle the routines that are invoked directly by vfs code. For instance: const struct inode_operations ocfs2_file_iops = { .permission = ocfs2_permission, .get_acl = ocfs2_iop_get_acl, .set_acl = ocfs2_iop_set_acl, }; Both ocfs2_permission() and ocfs2_iop_get_acl() call ocfs2_inode_lock(PR): do_sys_open may_open inode_permission ocfs2_permission ocfs2_inode_lock() <=== first time generic_permission get_acl ocfs2_iop_get_acl ocfs2_inode_lock() <=== recursive one A deadlock will occur if a remote EX request comes in between two of ocfs2_inode_lock(). Briefly describe how the deadlock is formed: On one hand, OCFS2_LOCK_BLOCKED flag of this lockres is set in BAST(ocfs2_generic_handle_bast) when downconvert is started on behalf of the remote EX lock request. Another hand, the recursive cluster lock (the second one) will be blocked in in __ocfs2_cluster_lock() because of OCFS2_LOCK_BLOCKED. But, the downconvert never complete, why? because there is no chance for the first cluster lock on this node to be unlocked - we block ourselves in the code path. The idea to fix this issue is mostly taken from gfs2 code. 1. introduce a new field: struct ocfs2_lock_res.l_holders, to keep track of the processes' pid who has taken the cluster lock of this lock resource; 2. introduce a new flag for ocfs2_inode_lock_full: OCFS2_META_LOCK_GETBH; it means just getting back disk inode bh for us if we've got cluster lock. 3. export a helper: ocfs2_is_locked_by_me() is used to check if we have got the cluster lock in the upper code path. The tracking logic should be used by some of the ocfs2 vfs's callbacks, to solve the recursive locking issue cuased by the fact that vfs routines can call into each other. The performance penalty of processing the holder list should only be seen at a few cases where the tracking logic is used, such as get/set acl. You may ask what if the first time we got a PR lock, and the second time we want a EX lock? fortunately, this case never happens in the real world, as far as I can see, including permission check, (get|set)_(acl|attr), and the gfs2 code also do so. [sfr@canb.auug.org.au remove some inlines] Link: http://lkml.kernel.org/r/20170117100948.11657-2-zren@suse.com Signed-off-by: Eric Ren <zren@suse.com> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22score: remove asm/current.hDavidlohr Bueso2-7/+1
... it's already using the generic version anyways, so just drop the file as do the other archs that do not implement their own version of the current macro. Link: http://lkml.kernel.org/r/1485992878-4780-5-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Cc: Chen Liqin <liqin.linux@gmail.com> Cc: Lennox Wu <lennox.wu@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22m32r: fix build warningSudip Mukherjee1-5/+10
Some m32r builds were having a warning: arch/m32r/include/asm/cmpxchg.h:191:3: warning: value computed is not used arch/m32r/include/asm/cmpxchg.h:68:3: warning: value computed is not used Taking the idea from commit e001bbae7147 ("ARM: cmpxchg: avoid warnings from macro-ized cmpxchg() implementations") the m32r implementation is changed to use a similar construct with a compound expression instead of a typecast, which causes the compiler to not complain about an unused result. Link: http://lkml.kernel.org/r/1484432664-7015-1-git-send-email-sudipm.mukherjee@gmail.com Signed-off-by: Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22m32r: use generic current.hDavidlohr Bueso2-15/+1
Given that the arch does not add its own implementations, simply use the asm-generic/current.h (generic-y) header instead of duplicating code. Link: http://lkml.kernel.org/r/1482896994-25863-1-git-send-email-dave@stgolabs.net Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/tags.sh: include arch/Kconfig* for tags generationHou Tao1-0/+2
Kconfig files under arch/ directory are ignored by all_kconfigs(), so include them for tags generation. Link: http://lkml.kernel.org/r/1486206053-38223-1-git-send-email-houtao1@huawei.com Signed-off-by: Hou Tao <houtao1@huawei.com> Cc: Michal Marek <mmarek@suse.com> Cc: Joe Perches <joe@perches.com> Cc: Mathieu Maret <mathieu.maret@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/checkincludes.pl: add exit message for no duplicates foundCheah Kok Cheong1-0/+8
If no duplicates found, inform user. Link: http://lkml.kernel.org/r/1486391275-2843-1-git-send-email-thrust73@gmail.com Signed-off-by: Cheah Kok Cheong <thrust73@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/checkstack.pl: add support for nios2Tobias Klauser1-0/+3
Adjust checkstack.pl for the nios2 architecture. Link: http://lkml.kernel.org/r/20170116113052.15034-1-tklauser@distanz.ch Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Cc: Ley Foon Tan <lftan@altera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/Lindent: clean up and optimizeJean Delvare1-5/+9
* Add a few blank lines to improve readability. * Don't call cut 3 times when once is enough. * Drop a useless semicolon. Link: http://lkml.kernel.org/r/20170104140356.162abab2@endymion Signed-off-by: Jean Delvare <jdelvare@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/spelling.txt: fix incorrect typo-wordsRoss Zwisler1-3/+3
Fix up some incorrect typo-words. [akpm@linux-foundation.org: "licencing" is valid British spelling and should be kept, per Joe] Link: http://lkml.kernel.org/r/1486409689-23335-1-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22scripts/spelling.txt: add several more common spelling mistakesColin Ian King1-0/+37
Lately I've been cleaning up spelling mistakes in kernel error messages and here are some of the more common spelling mistakes that I've found which probably should be added to this list so we don't keep on seeing them appearing again. Link: http://lkml.kernel.org/r/20161209173326.17662-1-colin.king@canonical.com Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22tools/vm: add missing Makefile rulesDaniel Thompson1-0/+8
Currently the tools/vm Makefile has a rather arbitrary implicit build rule; page-types is the first value in TARGETS so lets just build that one! Additionally there is no install rule and this is needed for make -C tools vm_install to work properly. Provide a more sensible implicit build rule and a new install rule. Note that the variables names used by the install rule (DESTDIR and sbindir) are copied from prior-art in tools/power/cpupower. Link: http://lkml.kernel.org/r/20170113165630.27541-1-daniel.thompson@linaro.org Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22dma-debug: add comment for failed to check map errorMiles Chen1-0/+5
Add comment for failure to check a map error to help driver developers. Link: http://lkml.kernel.org/r/1484622289-22085-1-git-send-email-miles.chen@mediatek.com Signed-off-by: Miles Chen <miles.chen@mediatek.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, dax: change pmd_fault() to take only vmf parameterDave Jiang8-85/+74
pmd_fault() and related functions really only need the vmf parameter since the additional parameters are all included in the vmf struct. Remove the additional parameter and simplify pmd_fault() and friends. Link: http://lkml.kernel.org/r/1484085142-2297-8-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22mm, dax: make pmd_fault() and friends be the same as fault()Dave Jiang8-55/+39
Instead of passing in multiple parameters in the pmd_fault() handler, a vmf can be passed in just like a fault() handler. This will simplify code and remove the need for the actual pmd fault handlers to allocate a vmf. Related functions are also modified to do the same. [dave.jiang@intel.com: fix issue with xfs_tests stall when DAX option is off] Link: http://lkml.kernel.org/r/148469861071.195597.3619476895250028518.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/1484085142-2297-7-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22dax: add tracepoints to dax_pmd_insert_mapping()Ross Zwisler3-3/+66
Add tracepoints to dax_pmd_insert_mapping(), following the same logging conventions as the tracepoints in dax_iomap_pmd_fault(). Here is an example PMD fault showing the new tracepoints: big-1504 [001] .... 326.960743: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 big-1504 [001] .... 326.960753: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 big-1504 [001] .... 326.960981: dax_pmd_insert_mapping: dev 259:0 ino 0x1003 shared write address 0x10505000 length 0x200000 pfn 0x100600 DEV|MAP radix_entry 0xc000e big-1504 [001] .... 326.960986: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-6-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22dax: add tracepoints to dax_pmd_load_hole()Ross Zwisler2-4/+52
Add tracepoints to dax_pmd_load_hole(), following the same logging conventions as the tracepoints in dax_iomap_pmd_fault(). Here is an example PMD fault showing the new tracepoints: read_big-1478 [004] .... 238.242188: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 read_big-1478 [004] .... 238.242191: dax_pmd_fault: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10400000 vm_start 0x10200000 vm_end 0x10600000 pgoff 0x200 max_pgoff 0x1400 read_big-1478 [004] .... 238.242390: dax_pmd_load_hole: dev 259:0 ino 0x1003 shared address 0x10400000 zero_page ffffea0002c20000 radix_entry 0x1e read_big-1478 [004] .... 238.242392: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10400000 vm_start 0x10200000 vm_end 0x10600000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-5-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22dax: update MAINTAINERS entries for FS DAXRoss Zwisler1-1/+4
Add the new include/trace/events/fs_dax.h tracepoint header, the existing include/linux/dax.h header, update Matthew's email address and add myself as a maintainer for filesystem DAX. Link: http://lkml.kernel.org/r/1484085142-2297-4-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22dax: add tracepoint infrastructure, PMD tracingRoss Zwisler3-10/+113
Tracepoints are the standard way to capture debugging and tracing information in many parts of the kernel, including the XFS and ext4 filesystems. Create a tracepoint header for FS DAX and add the first DAX tracepoints to the PMD fault handler. This allows the tracing for DAX to be done in the same way as the filesystem tracing so that developers can look at them together and get a coherent idea of what the system is doing. I added both an entry and exit tracepoint because future patches will add tracepoints to child functions of dax_iomap_pmd_fault() like dax_pmd_load_hole() and dax_pmd_insert_mapping(). We want those messages to be wrapped by the parent function tracepoints so the code flow is more easily understood. Having entry and exit tracepoints for faults also allows us to easily see what filesystems functions were called during the fault. These filesystem functions get executed via iomap_begin() and iomap_end() calls, for example, and will have their own tracepoints. For PMD faults we primarily want to understand the type of mapping, the fault flags, the faulting address and whether it fell back to 4k faults. If it fell back to 4k faults the tracepoints should let us understand why. I named the new tracepoint header file "fs_dax.h" to allow for device DAX to have its own separate tracing header in the same directory at some point. Here is an example output for these events from a successful PMD fault: big-1441 [005] .... 32.582758: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 big-1441 [005] .... 32.582776: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 big-1441 [005] .... 32.583292: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22tracing: add __print_flags_u64()Ross Zwisler3-0/+53
Patch series "DAX tracepoints, mm argument simplification", v4. This contains both my DAX tracepoint code and Dave Jiang's MM argument simplifications. Dave's code was written with my tracepoint code as a baseline, so it seemed simplest to keep them together in a single series. This patch (of 7): Add __print_flags_u64() and the helper trace_print_flags_seq_u64() in the same spirit as __print_symbolic_u64() and trace_print_symbols_seq_u64(). These functions allow us to print symbols associated with flags that are 64 bits wide even on 32 bit machines. These will be used by the DAX code so that we can print the flags set in a pfn_t such as PFN_SG_CHAIN, PFN_SG_LAST, PFN_DEV and PFN_MAP. Without this new function I was getting errors like the following when compiling for i386: include/linux/pfn_t.h:13:22: warning: large integer implicitly truncated to unsigned type [-Woverflow] #define PFN_SG_CHAIN (1ULL << (BITS_PER_LONG_LONG - 1)) ^ Link: http://lkml.kernel.org/r/1484085142-2297-2-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22Merge tag 'tty-4.11-rc1' of ↵Linus Torvalds116-1640/+3057
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial driver updates from Greg KH: "Here is the big tty/serial driver patchset for 4.11-rc1. Not much here, but a lot of little fixes and individual serial driver updates all over the subsystem. Majority are for the sh-sci driver and platform (the arch-specific changes have acks from the maintainer). The start of the "serial bus" code is here as well, but nothing is converted to use it yet. That work is still ongoing, hopefully will start to show up across different subsystems for 4.12 (bluetooth is one major place that will be used.) All of these have been in linux-next for a while with no reported issues" * tag 'tty-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (109 commits) tty: pl011: Work around QDF2400 E44 stuck BUSY bit atmel_serial: Use the fractional divider when possible tty: Remove extra include in HVC console tty framework serial: exar: Enable MSI support serial: exar: Move register defines from uapi header to consumer site serial: pci: Remove unused pci_boards entries serial: exar: Move Commtech adapters to 8250_exar as well serial: exar: Fix feature control register constants serial: exar: Fix initialization of EXAR registers for ports > 0 serial: exar: Fix mapping of port I/O resources serial: sh-sci: fix hardware RX trigger level setting tty/serial: atmel: ensure state is restored after suspending serial: 8250_dw: Avoid "too much work" from bogus rx timeout interrupt serdev: ttyport: check whether tty_init_dev() fails serial: 8250_pci: make pciserial_detach_ports() static ARM: dts: STiH410-b2260: Enable HW flow-control ARM: dts: STiH407-family: Use new Pinctrl groups ARM: dts: STiH407-pinctrl: Add Pinctrl group for HW flow-control ARM: dts: STiH410-b2260: Identify the UART RTS line dt-bindings: serial: Update 'uart-has-rtscts' description ...
2017-02-22Merge tag 'staging-4.11-rc1' of ↵Linus Torvalds669-20818/+25666
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/iio driver updates from Greg KH: "Here is the big staging and iio driver patchsets for 4.11-rc1. We almost broke even this time around, with only a few thousand lines added overall, as we removed the old and obsolete i4l code, but added some new drivers for the RPi platform, as well as adding some new IIO drivers. All of these have been in linux-next for a while with no reported issues" * tag 'staging-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (669 commits) Staging: vc04_services: Fix the "space prohibited" code style errors Staging: vc04_services: Fix the "wrong indent" code style errors staging: octeon: Use net_device_stats from struct net_device Staging: rtl8192u: ieee80211: ieee80211.h - style fix Staging: rtl8192u: ieee80211: ieee80211_tx.c - style fix Staging: rtl8192u: ieee80211: rtl819x_BAProc.c - style fix Staging: rtl8192u: ieee80211: ieee80211_module.c - style fix Staging: rtl8192u: ieee80211: rtl819x_TSProc.c - style fix Staging: rtl8192u: r8192U.h - style fix Staging: rtl8192u: r8192U_core.c - style fix Staging: rtl8192u: r819xU_cmdpkt.c - style fix staging: rtl8192u: blank lines aren't necessary before a close brace '}' staging: rtl8192u: Adding space after enum and struct definition staging: rtl8192u: Adding space after struct definition Staging: ks7010: Add required and preferred spaces around operators Staging: ks7010: ks*: Remove redundant blank lines Staging: ks7010: ks*: Add missing blank lines after declarations staging: visorbus, replace init_timer with setup_timer staging: vt6656: rxtx.c Removed multiple dereferencing staging: vt6656: Alignment match open parenthesis ...
2017-02-22Merge tag 'driver-core-4.11-rc1' of ↵Linus Torvalds27-173/+593
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the "small" driver core patches for 4.11-rc1. Not much here, some firmware documentation and self-test updates, a debugfs code formatting issue, and a new feature for call_usermodehelper to make it more robust on systems that want to lock it down in a more secure way. All of these have been linux-next for a while now with no reported issues" * tag 'driver-core-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: kernfs: handle null pointers while printing node name and path Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper() Make static usermode helper binaries constant kmod: make usermodehelper path a const string firmware: revamp firmware documentation selftests: firmware: send expected errors to /dev/null selftests: firmware: only modprobe if driver is missing platform: Print the resource range if device failed to claim kref: prefer atomic_inc_not_zero to atomic_add_unless debugfs: improve formatting of debugfs_real_fops()

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