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2015-11-05Merge branch 'for-4.4' of ↵Linus Torvalds2-8/+21
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup updates from Tejun Heo: "The cgroup core saw several significant updates this cycle: - percpu_rwsem for threadgroup locking is reinstated. This was temporarily dropped due to down_write latency issues. Oleg's rework of percpu_rwsem which is scheduled to be merged in this merge window resolves the issue. - On the v2 hierarchy, when controllers are enabled and disabled, all operations are atomic and can fail and revert cleanly. This allows ->can_attach() failure which is necessary for cpu RT slices. - Tasks now stay associated with the original cgroups after exit until released. This allows tracking resources held by zombies (e.g. pids) and makes it easy to find out where zombies came from on the v2 hierarchy. The pids controller was broken before these changes as zombies escaped the limits; unfortunately, updating this behavior required too many invasive changes and I don't think it's a good idea to backport them, so the pids controller on 4.3, the first version which included the pids controller, will stay broken at least until I'm sure about the cgroup core changes. - Optimization of a couple common tests using static_key" * 'for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (38 commits) cgroup: fix race condition around termination check in css_task_iter_next() blkcg: don't create "io.stat" on the root cgroup cgroup: drop cgroup__DEVEL__legacy_files_on_dfl cgroup: replace error handling in cgroup_init() with WARN_ON()s cgroup: add cgroup_subsys->free() method and use it to fix pids controller cgroup: keep zombies associated with their original cgroups cgroup: make css_set_rwsem a spinlock and rename it to css_set_lock cgroup: don't hold css_set_rwsem across css task iteration cgroup: reorganize css_task_iter functions cgroup: factor out css_set_move_task() cgroup: keep css_set and task lists in chronological order cgroup: make cgroup_destroy_locked() test cgroup_is_populated() cgroup: make css_sets pin the associated cgroups cgroup: relocate cgroup_[try]get/put() cgroup: move check_for_release() invocation cgroup: replace cgroup_has_tasks() with cgroup_is_populated() cgroup: make cgroup->nr_populated count the number of populated css_sets cgroup: remove an unused parameter from cgroup_task_migrate() cgroup: fix too early usage of static_branch_disable() cgroup: make cgroup_update_dfl_csses() migrate all target processes atomically ...
2015-11-04Merge tag 'driver-core-4.4-rc1' of ↵Linus Torvalds2-8/+8
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here's the "big" driver core updates for 4.4-rc1. Primarily a bunch of debugfs updates, with a smattering of minor driver core fixes and updates as well. All have been in linux-next for a long time" * tag 'driver-core-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: debugfs: Add debugfs_create_ulong() of: to support binding numa node to specified device in devicetree debugfs: Add read-only/write-only bool file ops debugfs: Add read-only/write-only size_t file ops debugfs: Add read-only/write-only x64 file ops debugfs: Consolidate file mode checks in debugfs_create_*() Revert "mm: Check if section present during memory block (un)registering" driver-core: platform: Provide helpers for multi-driver modules mm: Check if section present during memory block (un)registering devres: fix a for loop bounds check CMA: fix CONFIG_CMA_SIZE_MBYTES overflow in 64bit base/platform: assert that dev_pm_domain callbacks are called unconditionally sysfs: correctly handle short reads on PREALLOC attrs. base: soc: siplify ida usage kobject: move EXPORT_SYMBOL() macros next to corresponding definitions kobject: explain what kobject's sd field is debugfs: document that debugfs_remove*() accepts NULL and error values debugfs: Pass bool pointer to debugfs_create_bool() ACPI / EC: Fix broken 64bit big-endian users of 'global_lock'
2015-11-04Merge tag 'for-linus-4.4-rc0-tag' of ↵Linus Torvalds1-8/+21
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from David Vrabel: - Improve balloon driver memory hotplug placement. - Use unpopulated hotplugged memory for foreign pages (if supported/enabled). - Support 64 KiB guest pages on arm64. - CPU hotplug support on arm/arm64. * tag 'for-linus-4.4-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (44 commits) xen: fix the check of e_pfn in xen_find_pfn_range x86/xen: add reschedule point when mapping foreign GFNs xen/arm: don't try to re-register vcpu_info on cpu_hotplug. xen, cpu_hotplug: call device_offline instead of cpu_down xen/arm: Enable cpu_hotplug.c xenbus: Support multiple grants ring with 64KB xen/grant-table: Add an helper to iterate over a specific number of grants xen/xenbus: Rename *RING_PAGE* to *RING_GRANT* xen/arm: correct comment in enlighten.c xen/gntdev: use types from linux/types.h in userspace headers xen/gntalloc: use types from linux/types.h in userspace headers xen/balloon: Use the correct sizeof when declaring frame_list xen/swiotlb: Add support for 64KB page granularity xen/swiotlb: Pass addresses rather than frame numbers to xen_arch_need_swiotlb arm/xen: Add support for 64KB page granularity xen/privcmd: Add support for Linux 64KB page granularity net/xen-netback: Make it running on 64KB page granularity net/xen-netfront: Make it running on 64KB page granularity block/xen-blkback: Make it running on 64KB page granularity block/xen-blkfront: Make it running on 64KB page granularity ...
2015-11-03Merge tag 'arc-4.4-rc1' of ↵Linus Torvalds2-53/+49
git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc Pull ARC updates from Vineet Gupta: - Support for new MM features in ARCv2 cores (THP, PAE40) Some generic THP bits are touched - all ACKed by Kirill - Platform framework updates to prepare for EZChip arrival (still in works) - ARC Public Mailing list setup finally (linux-snps-arc@lists.infraded.org) * tag 'arc-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (42 commits) ARC: mm: PAE40 support ARC: mm: PAE40: tlbex.S: Explicitify the size of pte_t ARC: mm: PAE40: switch to using phys_addr_t for physical addresses ARC: mm: HIGHMEM: populate high memory from DT ARC: mm: HIGHMEM: kmap API implementation ARC: mm: preps ahead of HIGHMEM support #2 ARC: mm: preps ahead of HIGHMEM support ARC: mm: use generic macros _BITUL()/_AC() ARC: mm: Improve Duplicate PD Fault handler MAINTAINERS: Add public mailing list for ARC ARC: Ensure DT mem base is same as what kernel is built with ARC: boot: Non Master cpus only need to call EARLY_CPU_SETUP once ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_smp() ARC: smp: Introduce smp hook @init_irq_cpu called for all cores ARC: smp: Rename platform hook @init_smp -> @init_cpu_smp ARCv2: smp: [plat-*]: No need to explicitly call mcip_init_early_smp() ARC: smp: Introduce smp hook @init_early_smp for Master core ARC: remove @init_time, @init_irq platform callbacks ARC: smp: irqchip: handle IPI as percpu irq like timer ARC: boot: Support Halt-on-reset and Run-on-reset SMP booting modes ...
2015-11-01mm: get rid of 'vmalloc_info' from /proc/meminfoLinus Torvalds1-47/+0
It turns out that at least some versions of glibc end up reading /proc/meminfo at every single startup, because glibc wants to know the amount of memory the machine has. And while that's arguably insane, it's just how things are. And it turns out that it's not all that expensive most of the time, but the vmalloc information statistics (amount of virtual memory used in the vmalloc space, and the biggest remaining chunk) can be rather expensive to compute. The 'get_vmalloc_info()' function actually showed up on my profiles as 4% of the CPU usage of "make test" in the git source repository, because the git tests are lots of very short-lived shell-scripts etc. It turns out that apparently this same silly vmalloc info gathering shows up on the facebook servers too, according to Dave Jones. So it's not just "make test" for git. We had two patches to just cache the information (one by me, one by Ingo) to mitigate this issue, but the whole vmalloc information of of rather dubious value to begin with, and people who *actually* want to know what the situation is wrt the vmalloc area should just look at the much more complete /proc/vmallocinfo instead. In fact, according to my testing - and perhaps more importantly, according to that big search engine in the sky: Google - there is nothing out there that actually cares about those two expensive fields: VmallocUsed and VmallocChunk. So let's try to just remove them entirely. Actually, this just removes the computation and reports the numbers as zero for now, just to try to be minimally intrusive. If this breaks anything, we'll obviously have to re-introduce the code to compute this all and add the caching patches on top. But if given the option, I'd really prefer to just remove this bad idea entirely rather than add even more code to work around our historical mistake that likely nobody really cares about. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-24Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds3-46/+79
Pull block layer fixes from Jens Axboe: "A final set of fixes for 4.3. It is (again) bigger than I would have liked, but it's all been through the testing mill and has been carefully reviewed by multiple parties. Each fix is either a regression fix for this cycle, or is marked stable. You can scold me at KS. The pull request contains: - Three simple fixes for NVMe, fixing regressions since 4.3. From Arnd, Christoph, and Keith. - A single xen-blkfront fix from Cathy, fixing a NULL dereference if an error is returned through the staste change callback. - Fixup for some bad/sloppy code in nbd that got introduced earlier in this cycle. From Markus Pargmann. - A blk-mq tagset use-after-free fix from Junichi. - A backing device lifetime fix from Tejun, fixing a crash. - And finally, a set of regression/stable fixes for cgroup writeback from Tejun" * 'for-linus' of git://git.kernel.dk/linux-block: writeback: remove broken rbtree_postorder_for_each_entry_safe() usage in cgwb_bdi_destroy() NVMe: Fix memory leak on retried commands block: don't release bdi while request_queue has live references nvme: use an integer value to Linux errno values blk-mq: fix use-after-free in blk_mq_free_tag_set() nvme: fix 32-bit build warning writeback: fix incorrect calculation of available memory for memcg domains writeback: memcg dirty_throttle_control should be initialized with wb->memcg_completions writeback: bdi_writeback iteration must not skip dying ones writeback: fix bdi_writeback iteration in wakeup_dirtytime_writeback() writeback: laptop_mode_timer_fn() needs rcu_read_lock() around bdi_writeback iteration nbd: Add locking for tasks xen-blkfront: check for null drvdata in blkback_changed (XenbusStateClosing)
2015-10-23mm: memory hotplug with an existing resourceDavid Vrabel1-8/+21
Add add_memory_resource() to add memory using an existing "System RAM" resource. This is useful if the memory region is being located by finding a free resource slot with allocate_resource(). Xen guests will make use of this in their balloon driver to hotplug arbitrary amounts of memory in response to toolstack requests. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> Reviewed-by: Tang Chen <tangchen@cn.fujitsu.com>
2015-10-23mm: make sendfile(2) killableJan Kara1-4/+5
Currently a simple program below issues a sendfile(2) system call which takes about 62 days to complete in my test KVM instance. int fd; off_t off = 0; fd = open("file", O_RDWR | O_TRUNC | O_SYNC | O_CREAT, 0644); ftruncate(fd, 2); lseek(fd, 0, SEEK_END); sendfile(fd, fd, &off, 0xfffffff); Now you should not ask kernel to do a stupid stuff like copying 256MB in 2-byte chunks and call fsync(2) after each chunk but if you do, sysadmin should have a way to stop you. We actually do have a check for fatal_signal_pending() in generic_perform_write() which triggers in this path however because we always succeed in writing something before the check is done, we return value > 0 from generic_perform_write() and thus the information about signal gets lost. Fix the problem by doing the signal check before writing anything. That way generic_perform_write() returns -EINTR, the error gets propagated up and the sendfile loop terminates early. Signed-off-by: Jan Kara <jack@suse.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-23thp: use is_zero_pfn() only after pte_present() checkMinchan Kim1-1/+2
Use is_zero_pfn() on pteval only after pte_present() check on pteval (It might be better idea to introduce is_zero_pte() which checks pte_present() first). Otherwise when working on a swap or migration entry and if pte_pfn's result is equal to zero_pfn by chance, we lose user's data in __collapse_huge_page_copy(). So if you're unlucky, the application segfaults and finally you could see below message on exit: BUG: Bad rss-counter state mm:ffff88007f099300 idx:2 val:3 Fixes: ca0984caa823 ("mm: incorporate zero pages into transparent huge pages") Signed-off-by: Minchan Kim <minchan@kernel.org> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: <stable@vger.kernel.org> [4.1+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-23mm: cma: fix incorrect type conversion for size during dma allocationRohit Vaswani1-2/+2
This was found during userspace fuzzing test when a large size dma cma allocation is made by driver(like ion) through userspace. show_stack+0x10/0x1c dump_stack+0x74/0xc8 kasan_report_error+0x2b0/0x408 kasan_report+0x34/0x40 __asan_storeN+0x15c/0x168 memset+0x20/0x44 __dma_alloc_coherent+0x114/0x18c Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-21writeback: remove broken rbtree_postorder_for_each_entry_safe() usage in ↵Tejun Heo1-4/+6
cgwb_bdi_destroy() a20135ffbc44 ("writeback: don't drain bdi_writeback_congested on bdi destruction") added rbtree_postorder_for_each_entry_safe() which is used to remove all entries; however, according to Cody, the iterator isn't safe against operations which may rebalance the tree. Fix it by switching to repeatedly removing rb_first() until empty. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Cody P Schafer <dev@codyps.com> Fixes: a20135ffbc44 ("writeback: don't drain bdi_writeback_congested on bdi destruction") Link: http://lkml.kernel.org/g/1443997973-1700-1-git-send-email-dev@codyps.com Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-17mm,thp: introduce flush_pmd_tlb_rangeVineet Gupta2-7/+21
ARCHes with special requirements for evicting THP backing TLB entries can implement this. Otherwise also, it can help optimize TLB flush in THP regime. stock flush_tlb_range() typically has optimization to nuke the entire TLB if flush span is greater than a certain threshhold, which will likely be true for a single huge page. Thus a single thp flush will invalidate the entrire TLB which is not desirable. e.g. see arch/arc: flush_pmd_tlb_range Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: http://lkml.kernel.org/r/20151009100816.GC7873@node Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17mm,thp: reduce ifdef'ery for THP in generic codeVineet Gupta1-21/+3
- pgtable-generic.c: Fold individual #ifdef for each helper into a top level #ifdef. Makes code more readable - Converted the stub helpers for !THP to BUILD_BUG() vs. runtime BUG() Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Link: http://lkml.kernel.org/r/20151009133450.GA8597@node Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-17mm: group pte related helpers togetherVineet Gupta1-25/+25
This reduces/simplifies the diff for the next patch which moves THP specific code. No semantical changes ! Acked-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Link: http://lkml.kernel.org/r/1442918096-17454-9-git-send-email-vgupta@synopsys.com Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
2015-10-16Merge branch 'akpm' (patches from Andrew)Linus Torvalds3-4/+7
Merge misc fixes from Andrew Morton: "6 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: sh: add copy_user_page() alias for __copy_user() lib/Kconfig: ZLIB_DEFLATE must select BITREVERSE mm, dax: fix DAX deadlocks memcg: convert threshold to bytes builddeb: remove debian/files before build mm, fs: obey gfp_mapping for add_to_page_cache()
2015-10-16mm, dax: fix DAX deadlocksRoss Zwisler1-0/+2
The following two locking commits in the DAX code: commit 843172978bb9 ("dax: fix race between simultaneous faults") commit 46c043ede471 ("mm: take i_mmap_lock in unmap_mapping_range() for DAX") introduced a number of deadlocks and other issues which need to be fixed for the v4.3 kernel. The list of issues in DAX after these commits (some newly introduced by the commits, some preexisting) can be found here: https://lkml.org/lkml/2015/9/25/602 (Subject: "Re: [PATCH] dax: fix deadlock in __dax_fault"). This undoes most of the changes introduced by those two commits, essentially returning us to the DAX locking scheme that was used in v4.2. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Tested-by: Dave Chinner <dchinner@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-16memcg: convert threshold to bytesShaohua Li1-0/+1
page_counter_memparse() returns pages for the threshold, while mem_cgroup_usage() returns bytes for memory usage. Convert the threshold to bytes. Fixes: 3e32cb2e0a12b6915 ("memcg: rename cgroup_event to mem_cgroup_event"). Signed-off-by: Shaohua Li <shli@fb.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-16mm, fs: obey gfp_mapping for add_to_page_cache()Michal Hocko1-4/+4
Commit 6afdb859b710 ("mm: do not ignore mapping_gfp_mask in page cache allocation paths") has caught some users of hardcoded GFP_KERNEL used in the page cache allocation paths. This, however, wasn't complete and there were others which went unnoticed. Dave Chinner has reported the following deadlock for xfs on loop device: : With the recent merge of the loop device changes, I'm now seeing : XFS deadlock on my single CPU, 1GB RAM VM running xfs/073. : : The deadlocked is as follows: : : kloopd1: loop_queue_read_work : xfs_file_iter_read : lock XFS inode XFS_IOLOCK_SHARED (on image file) : page cache read (GFP_KERNEL) : radix tree alloc : memory reclaim : reclaim XFS inodes : log force to unpin inodes : <wait for log IO completion> : : xfs-cil/loop1: <does log force IO work> : xlog_cil_push : xlog_write : <loop issuing log writes> : xlog_state_get_iclog_space() : <blocks due to all log buffers under write io> : <waits for IO completion> : : kloopd1: loop_queue_write_work : xfs_file_write_iter : lock XFS inode XFS_IOLOCK_EXCL (on image file) : <wait for inode to be unlocked> : : i.e. the kloopd, with it's split read and write work queues, has : introduced a dependency through memory reclaim. i.e. that writes : need to be able to progress for reads make progress. : : The problem, fundamentally, is that mpage_readpages() does a : GFP_KERNEL allocation, rather than paying attention to the inode's : mapping gfp mask, which is set to GFP_NOFS. : : The didn't used to happen, because the loop device used to issue : reads through the splice path and that does: : : error = add_to_page_cache_lru(page, mapping, index, : GFP_KERNEL & mapping_gfp_mask(mapping)); This has changed by commit aa4d86163e4 ("block: loop: switch to VFS ITER_BVEC"). This patch changes mpage_readpage{s} to follow gfp mask set for the mapping. There are, however, other places which are doing basically the same. lustre:ll_dir_filler is doing GFP_KERNEL from the function which apparently uses GFP_NOFS for other allocations so let's make this consistent. cifs:readpages_get_pages is called from cifs_readpages and __cifs_readpages_from_fscache called from the same path obeys mapping gfp. ramfs_nommu_expand_for_mapping is hardcoding GFP_KERNEL as well regardless it uses mapping_gfp_mask for the page allocation. ext4_mpage_readpages is the called from the page cache allocation path same as read_pages and read_cache_pages As I've noticed in my previous post I cannot say I would be happy about sprinkling mapping_gfp_mask all over the place and it sounds like we should drop gfp_mask argument altogether and use it internally in __add_to_page_cache_locked that would require all the filesystems to use mapping gfp consistently which I am not sure is the case here. From a quick glance it seems that some file system use it all the time while others are selective. Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Dave Chinner <david@fromorbit.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Ming Lei <ming.lei@canonical.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-15cgroup: replace cgroup_has_tasks() with cgroup_is_populated()Tejun Heo1-1/+1
Currently, cgroup_has_tasks() tests whether the target cgroup has any css_set linked to it. This works because a css_set's refcnt converges with the number of tasks linked to it and thus there's no css_set linked to a cgroup if it doesn't have any live tasks. To help tracking resource usage of zombie tasks, putting the ref of css_set will be separated from disassociating the task from the css_set which means that a cgroup may have css_sets linked to it even when it doesn't have any live tasks. This patch replaces cgroup_has_tasks() with cgroup_is_populated() which tests cgroup->nr_populated instead which locally counts the number of populated css_sets. Unlike cgroup_has_tasks(), cgroup_is_populated() is recursive - if any of the descendants is populated, the cgroup is populated too. While this changes the meaning of the test, all the existing users are okay with the change. While at it, replace the open-coded ->populated_cnt test in cgroup_events_show() with cgroup_is_populated(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org>
2015-10-15vmstat: explicitly schedule per-cpu work on the CPU we need it to run onLinus Torvalds1-3/+4
The vmstat code uses "schedule_delayed_work_on()" to do the initial startup of the delayed work on the right CPU, but then once it was started it would use the non-cpu-specific "schedule_delayed_work()" to re-schedule it on that CPU. That just happened to schedule it on the same CPU historically (well, in almost all situations), but the code _requires_ this work to be per-cpu, and should say so explicitly rather than depend on the non-cpu-specific scheduling to schedule on the current CPU. The timer code is being changed to not be as single-minded in always running things on the calling CPU. See also commit 874bbfe600a6 ("workqueue: make sure delayed work run in local cpu") that for now maintains the local CPU guarantees just in case there are other broken users that depended on the accidental behavior. Cc: Christoph Lameter <cl@linux.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-15block: don't release bdi while request_queue has live referencesTejun Heo1-1/+11
bdi's are initialized in two steps, bdi_init() and bdi_register(), but destroyed in a single step by bdi_destroy() which, for a bdi embedded in a request_queue, is called during blk_cleanup_queue() which makes the queue invisible and starts the draining of remaining usages. A request_queue's user can access the congestion state of the embedded bdi as long as it holds a reference to the queue. As such, it may access the congested state of a queue which finished blk_cleanup_queue() but hasn't reached blk_release_queue() yet. Because the congested state was embedded in backing_dev_info which in turn is embedded in request_queue, accessing the congested state after bdi_destroy() was called was fine. The bdi was destroyed but the memory region for the congested state remained accessible till the queue got released. a13f35e87140 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback") changed the situation. Now, the root congested state which is expected to be pinned while request_queue remains accessible is separately reference counted and the base ref is put during bdi_destroy(). This means that the root congested state may go away prematurely while the queue is between bdi_dstroy() and blk_cleanup_queue(), which was detected by Andrey's KASAN tests. The root cause of this problem is that bdi doesn't distinguish the two steps of destruction, unregistration and release, and now the root congested state actually requires a separate release step. To fix the issue, this patch separates out bdi_unregister() and bdi_exit() from bdi_destroy(). bdi_unregister() is called from blk_cleanup_queue() and bdi_exit() from blk_release_queue(). bdi_destroy() is now just a simple wrapper calling the two steps back-to-back. While at it, the prototype of bdi_destroy() is moved right below bdi_setup_and_register() so that the counterpart operations are located together. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: a13f35e87140 ("writeback: don't embed root bdi_writeback_congested in bdi_writeback") Cc: stable@vger.kernel.org # v4.2+ Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com> Link: http://lkml.kernel.org/g/CAAeHK+zUJ74Zn17=rOyxacHU18SgCfC6bsYW=6kCY5GXJBwGfQ@mail.gmail.com Reviewed-by: Jan Kara <jack@suse.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12writeback: fix incorrect calculation of available memory for memcg domainsTejun Heo2-29/+35
For memcg domains, the amount of available memory was calculated as min(the amount currently in use + headroom according to memcg, total clean memory) This isn't quite correct as what should be capped by the amount of clean memory is the headroom, not the sum of memory in use and headroom. For example, if a memcg domain has a significant amount of dirty memory, the above can lead to a value which is lower than the current amount in use which doesn't make much sense. In most circumstances, the above leads to a number which is somewhat but not drastically lower. As the amount of memory which can be readily allocated to the memcg domain is capped by the amount of system-wide clean memory which is not already assigned to the memcg itself, the number we want is the amount currently in use + min(headroom according to memcg, clean memory elsewhere in the system) This patch updates mem_cgroup_wb_stats() to return the number of filepages and headroom instead of the calculated available pages. mdtc_cap_avail() is renamed to mdtc_calc_avail() and performs the above calculation from file, headroom, dirty and globally clean pages. v2: Dummy mem_cgroup_wb_stats() implementation wasn't updated leading to build failure when !CGROUP_WRITEBACK. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: c2aa723a6093 ("writeback: implement memcg writeback domain based throttling") Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12writeback: memcg dirty_throttle_control should be initialized with ↵Tejun Heo1-9/+11
wb->memcg_completions MDTC_INIT() is used to initialize dirty_throttle_control for memcg domains. It used DTC_INIT_COMMON() to initialized mdtc->wb and ->wb_completions which is incorrect as DTC_INIT_COMMON() sets the latter to wb->completions instead of wb->memcg_completions. This can lead to wildly incorrect results when calculating the proportion of dirty memory the memcg domain should get. Remove DTC_INIT_COMMON() and update MDTC_INIT() to initialize mdtc->wb_completions to wb->memcg_completions. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: c2aa723a6093 ("writeback: implement memcg writeback domain based throttling") Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12writeback: bdi_writeback iteration must not skip dying onesTejun Heo2-3/+14
bdi_for_each_wb() is used in several places to wake up or issue writeback work items to all wb's (bdi_writeback's) on a given bdi. The iteration is performed by walking bdi->cgwb_tree; however, the tree only indexes wb's which are currently active. For example, when a memcg gets associated with a different blkcg, the old wb is removed from the tree so that the new one can be indexed. The old wb starts dying from then on but will linger till all its inodes are drained. As these dying wb's may still host dirty inodes, writeback operations which affect all wb's must include them. bdi_for_each_wb() skipping dying wb's led to sync(2) missing and failing to sync the inodes belonging to those wb's. This patch adds a RCU protected @bdi->wb_list which lists all wb's beloinging to that bdi. wb's are added on creation and removed on release rather than on the start of destruction. bdi_for_each_wb() usages are replaced with list_for_each[_continue]_rcu() iterations over @bdi->wb_list and bdi_for_each_wb() and its helpers are removed. v2: Updated as per Jan. last_wb ref leak in bdi_split_work_to_wbs() fixed and unnecessary list head severing in cgwb_bdi_destroy() removed. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Artem Bityutskiy <dedekind1@gmail.com> Fixes: ebe41ab0c79d ("writeback: implement bdi_for_each_wb()") Link: http://lkml.kernel.org/g/1443012552.19983.209.camel@gmail.com Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-12writeback: laptop_mode_timer_fn() needs rcu_read_lock() around bdi_writeback ↵Tejun Heo1-0/+2
iteration laptop_mode_timer_fn() was using bdi_for_each_wb() without the required RCU locking leading to the following warning. WARNING: CPU: 0 PID: 0 at include/linux/backing-dev.h:415 laptop_mode_timer_fn+0x106/0x170() ... Call Trace: <IRQ> [<ffffffff81480cdc>] dump_stack+0x4e/0x82 [<ffffffff81051912>] warn_slowpath_common+0x82/0xc0 [<ffffffff81051a0a>] warn_slowpath_null+0x1a/0x20 [<ffffffff8115f0e6>] laptop_mode_timer_fn+0x106/0x170 [<ffffffff810ca8e3>] call_timer_fn+0xb3/0x2f0 [<ffffffff810cad25>] run_timer_softirq+0x205/0x370 [<ffffffff81056854>] __do_softirq+0xd4/0x460 [<ffffffff81056d69>] irq_exit+0x89/0xa0 [<ffffffff8185a892>] smp_apic_timer_interrupt+0x42/0x50 [<ffffffff81858a44>] apic_timer_interrupt+0x84/0x90 ... Fix it by adding rcu_read_lock() around the iteration. Signed-off-by: Tejun Heo <tj@kernel.org> Fixes: a06fd6b10228 ("writeback: make laptop_mode_timer_fn() handle multiple bdi_writeback's") Reviewed-by: Jan Kara <jack@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-10-07Revert "fs: do not prefault sys_write() user buffer pages"Linus Torvalds1-18/+16
This reverts commit 998ef75ddb5709bbea0bf1506cd2717348a3c647. The commit itself does not appear to be buggy per se, but it is exposing a bug in ext4 (and Ted thinks ext3 too, but we solved that by getting rid of it). It's too late in the release cycle to really worry about this, even if Dave Hansen has a patch that may actually fix the underlying ext4 problem. We can (and should) revisit this for the next release. The problem is that moving the prefaulting later now exposes a special case with partially successful writes that isn't handled correctly. And the prefaulting likely isn't normally even that much of a performance issue - it looks like at least one reason Dave saw this in his performance tests is that he also ran them on Skylake that now supports the new SMAP code, which makes the normally very cheap user space prefaulting noticeably more expensive. Bisected-and-acked-by: Ted Ts'o <tytso@mit.edu> Analyzed-and-acked-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-04debugfs: Pass bool pointer to debugfs_create_bool()Viresh Kumar2-8/+8
Its a bit odd that debugfs_create_bool() takes 'u32 *' as an argument, when all it needs is a boolean pointer. It would be better to update this API to make it accept 'bool *' instead, as that will make it more consistent and often more convenient. Over that bool takes just a byte. That required updates to all user sites as well, in the same commit updating the API. regmap core was also using debugfs_{read|write}_file_bool(), directly and variable types were updated for that to be bool as well. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-01dmapool: fix overflow condition in pool_find_page()Robin Murphy1-1/+1
If a DMA pool lies at the very top of the dma_addr_t range (as may happen with an IOMMU involved), the calculated end address of the pool wraps around to zero, and page lookup always fails. Tweak the relevant calculation to be overflow-proof. Signed-off-by: Robin Murphy <robin.murphy@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Marek Szyprowski <m.szyprowski@samsung.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Sakari Ailus <sakari.ailus@iki.fi> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01memcg: remove pcp_counter_lockGreg Thelen1-1/+0
Commit 733a572e66d2 ("memcg: make mem_cgroup_read_{stat|event}() iterate possible cpus instead of online") removed the last use of the per memcg pcp_counter_lock but forgot to remove the variable. Kill the vestigial variable. Signed-off-by: Greg Thelen <gthelen@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01memcg: make mem_cgroup_read_stat() unsignedGreg Thelen1-12/+18
mem_cgroup_read_stat() returns a page count by summing per cpu page counters. The summing is racy wrt. updates, so a transient negative sum is possible. Callers don't want negative values: - mem_cgroup_wb_stats() doesn't want negative nr_dirty or nr_writeback. This could confuse dirty throttling. - oom reports and memory.stat shouldn't show confusing negative usage. - tree_usage() already avoids negatives. Avoid returning negative page counts from mem_cgroup_read_stat() and convert it to unsigned. [akpm@linux-foundation.org: fix old typo while we're in there] Signed-off-by: Greg Thelen <gthelen@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01memcg: fix dirty page migrationGreg Thelen1-1/+11
The problem starts with a file backed dirty page which is charged to a memcg. Then page migration is used to move oldpage to newpage. Migration: - copies the oldpage's data to newpage - clears oldpage.PG_dirty - sets newpage.PG_dirty - uncharges oldpage from memcg - charges newpage to memcg Clearing oldpage.PG_dirty decrements the charged memcg's dirty page count. However, because newpage is not yet charged, setting newpage.PG_dirty does not increment the memcg's dirty page count. After migration completes newpage.PG_dirty is eventually cleared, often in account_page_cleaned(). At this time newpage is charged to a memcg so the memcg's dirty page count is decremented which causes underflow because the count was not previously incremented by migration. This underflow causes balance_dirty_pages() to see a very large unsigned number of dirty memcg pages which leads to aggressive throttling of buffered writes by processes in non root memcg. This issue: - can harm performance of non root memcg buffered writes. - can report too small (even negative) values in memory.stat[(total_)dirty] counters of all memcg, including the root. To avoid polluting migrate.c with #ifdef CONFIG_MEMCG checks, introduce page_memcg() and set_page_memcg() helpers. Test: 0) setup and enter limited memcg mkdir /sys/fs/cgroup/test echo 1G > /sys/fs/cgroup/test/memory.limit_in_bytes echo $$ > /sys/fs/cgroup/test/cgroup.procs 1) buffered writes baseline dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k sync grep ^dirty /sys/fs/cgroup/test/memory.stat 2) buffered writes with compaction antagonist to induce migration yes 1 > /proc/sys/vm/compact_memory & rm -rf /data/tmp/foo dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k kill % sync grep ^dirty /sys/fs/cgroup/test/memory.stat 3) buffered writes without antagonist, should match baseline rm -rf /data/tmp/foo dd if=/dev/zero of=/data/tmp/foo bs=1M count=1k sync grep ^dirty /sys/fs/cgroup/test/memory.stat (speed, dirty residue) unpatched patched 1) 841 MB/s 0 dirty pages 886 MB/s 0 dirty pages 2) 611 MB/s -33427456 dirty pages 793 MB/s 0 dirty pages 3) 114 MB/s -33427456 dirty pages 891 MB/s 0 dirty pages Notice that unpatched baseline performance (1) fell after migration (3): 841 -> 114 MB/s. In the patched kernel, post migration performance matches baseline. Fixes: c4843a7593a9 ("memcg: add per cgroup dirty page accounting") Signed-off-by: Greg Thelen <gthelen@google.com> Reported-by: Dave Hansen <dave.hansen@intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: <stable@vger.kernel.org> [4.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01mm: hugetlbfs: skip shared VMAs when unmapping private pages to satisfy a faultMel Gorman1-0/+8
SunDong reported the following on https://bugzilla.kernel.org/show_bug.cgi?id=103841 I think I find a linux bug, I have the test cases is constructed. I can stable recurring problems in fedora22(4.0.4) kernel version, arch for x86_64. I construct transparent huge page, when the parent and child process with MAP_SHARE, MAP_PRIVATE way to access the same huge page area, it has the opportunity to lead to huge page copy on write failure, and then it will munmap the child corresponding mmap area, but then the child mmap area with VM_MAYSHARE attributes, child process munmap this area can trigger VM_BUG_ON in set_vma_resv_flags functions (vma - > vm_flags & VM_MAYSHARE). There were a number of problems with the report (e.g. it's hugetlbfs that triggers this, not transparent huge pages) but it was fundamentally correct in that a VM_BUG_ON in set_vma_resv_flags() can be triggered that looks like this vma ffff8804651fd0d0 start 00007fc474e00000 end 00007fc475e00000 next ffff8804651fd018 prev ffff8804651fd188 mm ffff88046b1b1800 prot 8000000000000027 anon_vma (null) vm_ops ffffffff8182a7a0 pgoff 0 file ffff88106bdb9800 private_data (null) flags: 0x84400fb(read|write|shared|mayread|maywrite|mayexec|mayshare|dontexpand|hugetlb) ------------ kernel BUG at mm/hugetlb.c:462! SMP Modules linked in: xt_pkttype xt_LOG xt_limit [..] CPU: 38 PID: 26839 Comm: map Not tainted 4.0.4-default #1 Hardware name: Dell Inc. PowerEdge R810/0TT6JF, BIOS 2.7.4 04/26/2012 set_vma_resv_flags+0x2d/0x30 The VM_BUG_ON is correct because private and shared mappings have different reservation accounting but the warning clearly shows that the VMA is shared. When a private COW fails to allocate a new page then only the process that created the VMA gets the page -- all the children unmap the page. If the children access that data in the future then they get killed. The problem is that the same file is mapped shared and private. During the COW, the allocation fails, the VMAs are traversed to unmap the other private pages but a shared VMA is found and the bug is triggered. This patch identifies such VMAs and skips them. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: SunDong <sund_sky@126.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: David Rientjes <rientjes@google.com> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-10-01mm/slab: fix unexpected index mapping result of kmalloc_size(INDEX_NODE+1)Joonsoo Kim1-3/+10
Commit description is copied from the original post of this bug: http://comments.gmane.org/gmane.linux.kernel.mm/135349 Kernels after v3.9 use kmalloc_size(INDEX_NODE + 1) to get the next larger cache size than the size index INDEX_NODE mapping. In kernels 3.9 and earlier we used malloc_sizes[INDEX_L3 + 1].cs_size. However, sometimes we can't get the right output we expected via kmalloc_size(INDEX_NODE + 1), causing a BUG(). The mapping table in the latest kernel is like: index = {0, 1, 2 , 3, 4, 5, 6, n} size = {0, 96, 192, 8, 16, 32, 64, 2^n} The mapping table before 3.10 is like this: index = {0 , 1 , 2, 3, 4 , 5 , 6, n} size = {32, 64, 96, 128, 192, 256, 512, 2^(n+3)} The problem on my mips64 machine is as follows: (1) When configured DEBUG_SLAB && DEBUG_PAGEALLOC && DEBUG_LOCK_ALLOC && DEBUG_SPINLOCK, the sizeof(struct kmem_cache_node) will be "150", and the macro INDEX_NODE turns out to be "2": #define INDEX_NODE kmalloc_index(sizeof(struct kmem_cache_node)) (2) Then the result of kmalloc_size(INDEX_NODE + 1) is 8. (3) Then "if(size >= kmalloc_size(INDEX_NODE + 1)" will lead to "size = PAGE_SIZE". (4) Then "if ((size >= (PAGE_SIZE >> 3))" test will be satisfied and "flags |= CFLGS_OFF_SLAB" will be covered. (5) if (flags & CFLGS_OFF_SLAB)" test will be satisfied and will go to "cachep->slabp_cache = kmalloc_slab(slab_size, 0u)", and the result here may be NULL while kernel bootup. (6) Finally,"BUG_ON(ZERO_OR_NULL_PTR(cachep->slabp_cache));" causes the BUG info as the following shows (may be only mips64 has this problem): This patch fixes the problem of kmalloc_size(INDEX_NODE + 1) and removes the BUG by adding 'size >= 256' check to guarantee that all necessary small sized slabs are initialized regardless sequence of slab size in mapping table. Fixes: e33660165c90 ("slab: Use common kmalloc_index/kmalloc_size...") Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Reported-by: Liuhailong <liu.hailong6@zte.com.cn> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22vmscan: fix sane_reclaim helper for legacy memcgVladimir Davydov1-1/+1
The sane_reclaim() helper is supposed to return false for memcg reclaim if the legacy hierarchy is used, because the latter lacks dirty throttling mechanism, and so it did before it was accidentally broken by commit 33398cf2f360c ("memcg: export struct mem_cgroup"). Fix it. Fixes: 33398cf2f360c ("memcg: export struct mem_cgroup") Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.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>
2015-09-22mm: migrate: hugetlb: putback destination hugepage to active listNaoya Horiguchi1-1/+1
Since commit bcc54222309c ("mm: hugetlb: introduce page_huge_active") each hugetlb page maintains its active flag to avoid a race condition betwe= en multiple calls of isolate_huge_page(), but current kernel doesn't set the f= lag on a hugepage allocated by migration because the proper putback routine isn= 't called. This means that users could still encounter the race referred to by bcc54222309c in this special case, so this patch fixes it. Fixes: bcc54222309c ("mm: hugetlb: introduce page_huge_active") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Andi Kleen <andi@firstfloor.org> Cc: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [4.1.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22mm, dax: VMA with vm_ops->pfn_mkwrite wants to be write-notifiedKirill A. Shutemov1-1/+2
For VM_PFNMAP and VM_MIXEDMAP we use vm_ops->pfn_mkwrite instead of vm_ops->page_mkwrite to notify abort write access. This means we want vma->vm_page_prot to be write-protected if the VMA provides this vm_ops. A theoretical scenario that will cause these missed events is: On writable mapping with vm_ops->pfn_mkwrite, but without vm_ops->page_mkwrite: read fault followed by write access to the pfn. Writable pte will be set up on read fault and write fault will not be generated. I found it examining Dave's complaint on generic/080: http://lkml.kernel.org/g/20150831233803.GO3902@dastard Although I don't think it's the reason. It shouldn't be a problem for ext2/ext4 as they provide both pfn_mkwrite and page_mkwrite. [akpm@linux-foundation.org: add local vm_ops to avoid 80-cols mess] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Yigal Korman <yigal@plexistor.com> Acked-by: Boaz Harrosh <boaz@plexistor.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-22cgroup, memcg, cpuset: implement cgroup_taskset_for_each_leader()Tejun Heo1-2/+15
It wasn't explicitly documented but, when a process is being migrated, cpuset and memcg depend on cgroup_taskset_first() returning the threadgroup leader; however, this approach is somewhat ghetto and would no longer work for the planned multi-process migration. This patch introduces explicit cgroup_taskset_for_each_leader() which iterates over only the threadgroup leaders and replaces cgroup_taskset_first() usages for accessing the leader with it. This prepares both memcg and cpuset for multi-process migration. This patch also updates the documentation for cgroup_taskset_for_each() to clarify the iteration rules and removes comments mentioning task ordering in tasksets. v2: A previous patch which added threadgroup leader test was dropped. Patch updated accordingly. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org>
2015-09-21memcg: generate file modified notifications on "memory.events"Tejun Heo1-0/+1
cgroup core only recently grew generic notification support. Wire up "memory.events" so that it triggers a file modified event whenever its content changes. v2: Refreshed on top of mem_cgroup relocation. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Li Zefan <lizefan@huawei.com>
2015-09-18cgroup: replace cftype->mode with CFTYPE_WORLD_WRITABLETejun Heo1-2/+1
cftype->mode allows controllers to give arbitrary permissions to interface knobs. Except for "cgroup.event_control", the existing uses are spurious. * Some explicitly specify S_IRUGO | S_IWUSR even though that's the default. * "cpuset.memory_pressure" specifies S_IRUGO while also setting a write callback which returns -EACCES. All it needs to do is simply not setting a write callback. "cgroup.event_control" uses cftype->mode to make the file world-writable. It's a misdesigned interface and we don't want controllers to be tweaking interface file permissions in general. This patch removes cftype->mode and all its spurious uses and implements CFTYPE_WORLD_WRITABLE for "cgroup.event_control" which is marked as compatibility-only. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Johannes Weiner <hannes@cmpxchg.org>
2015-09-18cgroup: replace cgroup_on_dfl() tests in controllers with cgroup_subsys_on_dfl()Tejun Heo1-2/+2
cgroup_on_dfl() tests whether the cgroup's root is the default hierarchy; however, an individual controller is only interested in whether the controller is attached to the default hierarchy and never tests a cgroup which doesn't belong to the hierarchy that the controller is attached to. This patch replaces cgroup_on_dfl() tests in controllers with faster static_key based cgroup_subsys_on_dfl(). This leaves cgroup core as the only user of cgroup_on_dfl() and the function is moved from the header file to cgroup.c. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org>
2015-09-17revert "mm: make sure all file VMAs have ->vm_ops set"Andrew Morton1-8/+0
Revert commit 6dc296e7df4c "mm: make sure all file VMAs have ->vm_ops set". Will Deacon reports that it "causes some mmap regressions in LTP, which appears to use a MAP_PRIVATE mmap of /dev/zero as a way to get anonymous pages in some of its tests (specifically mmap10 [1])". William Shuman reports Oracle crashes. So revert the patch while we work out what to do. Reported-by: William Shuman <wshuman3@gmail.com> Reported-by: Will Deacon <will.deacon@arm.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-17kasan: fix last shadow judgement in memory_is_poisoned_16()Xishi Qiu1-2/+1
The shadow which correspond 16 bytes memory may span 2 or 3 bytes. If the memory is aligned on 8, then the shadow takes only 2 bytes. So we check "shadow_first_bytes" is enough, and need not to call "memory_is_poisoned_1(addr + 15);". But the code "if (likely(!last_byte))" is wrong judgement. e.g. addr=0, so last_byte = 15 & KASAN_SHADOW_MASK = 7, then the code will continue to call "memory_is_poisoned_1(addr + 15);" Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Acked-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Michal Marek <mmarek@suse.cz> Cc: <zhongjiang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-11Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-0/+1
Merge fourth patch-bomb from Andrew Morton: - sys_membarier syscall - seq_file interface changes - a few misc fixups * emailed patches from Andrew Morton <akpm@linux-foundation.org>: revert "ocfs2/dlm: use list_for_each_entry instead of list_for_each" mm/early_ioremap: add explicit #include of asm/early_ioremap.h fs/seq_file: convert int seq_vprint/seq_printf/etc... returns to void selftests: enhance membarrier syscall test selftests: add membarrier syscall test sys_membarrier(): system-wide memory barrier (generic, x86) MODSIGN: fix a compilation warning in extract-cert
2015-09-11Merge tag 'media/v4.3-2' of ↵Linus Torvalds3-0/+234
git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media Pull media updates from Mauro Carvalho Chehab: "A series of patches that move part of the code used to allocate memory from the media subsystem to the mm subsystem" [ The mm parts have been acked by VM people, and the series was apparently in -mm for a while - Linus ] * tag 'media/v4.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: [media] drm/exynos: Convert g2d_userptr_get_dma_addr() to use get_vaddr_frames() [media] media: vb2: Remove unused functions [media] media: vb2: Convert vb2_dc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_vmalloc_get_userptr() to use frame vector [media] media: vb2: Convert vb2_dma_sg_get_userptr() to use frame vector [media] vb2: Provide helpers for mapping virtual addresses [media] media: omap_vout: Convert omap_vout_uservirt_to_phys() to use get_vaddr_pfns() [media] mm: Provide new get_vaddr_frames() helper [media] vb2: Push mmap_sem down to memops
2015-09-11mm/early_ioremap: add explicit #include of asm/early_ioremap.hArd Biesheuvel1-0/+1
Commit 6b0f68e32ea8 ("mm: add utility for early copy from unmapped ram") introduces a function copy_from_early_mem() into mm/early_ioremap.c which itself calls early_memremap()/early_memunmap(). However, since early_memunmap() has not been declared yet at this point in the .c file, nor by any explicitly included header files, we are depending on a transitive include of asm/early_ioremap.h to declare it, which is fragile. So instead, include this header explicitly. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: Mark Salter <msalter@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-blockLinus Torvalds2-5/+5
Pull blk-cg updates from Jens Axboe: "A bit later in the cycle, but this has been in the block tree for a a while. This is basically four patchsets from Tejun, that improve our buffered cgroup writeback. It was dependent on the other cgroup changes, but they went in earlier in this cycle. Series 1 is set of 5 patches that has cgroup writeback updates: - bdi_writeback iteration fix which could lead to some wb's being skipped or repeated during e.g. sync under memory pressure. - Simplification of wb work wait mechanism. - Writeback tracepoints updated to report cgroup. Series 2 is is a set of updates for the CFQ cgroup writeback handling: cfq has always charged all async IOs to the root cgroup. It didn't have much choice as writeback didn't know about cgroups and there was no way to tell who to blame for a given writeback IO. writeback finally grew support for cgroups and now tags each writeback IO with the appropriate cgroup to charge it against. This patchset updates cfq so that it follows the blkcg each bio is tagged with. Async cfq_queues are now shared across cfq_group, which is per-cgroup, instead of per-request_queue cfq_data. This makes all IOs follow the weight based IO resource distribution implemented by cfq. - Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff. - Other misc review points addressed, acks added and rebased. Series 3 is the blkcg policy cleanup patches: This patchset contains assorted cleanups for blkcg_policy methods and blk[c]g_policy_data handling. - alloc/free added for blkg_policy_data. exit dropped. - alloc/free added for blkcg_policy_data. - blk-throttle's async percpu allocation is replaced with direct allocation. - all methods now take blk[c]g_policy_data instead of blkcg_gq or blkcg. And finally, series 4 is a set of patches cleaning up the blkcg stats handling: blkcg's stats have always been somwhat of a mess. This patchset tries to improve the situation a bit. - The following patches added to consolidate blkcg entry point and blkg creation. This is in itself is an improvement and helps colllecting common stats on bio issue. - per-blkg stats now accounted on bio issue rather than request completion so that bio based and request based drivers can behave the same way. The issue was spotted by Vivek. - cfq-iosched implements custom recursive stats and blk-throttle implements custom per-cpu stats. This patchset make blkcg core support both by default. - cfq-iosched and blk-throttle keep track of the same stats multiple times. Unify them" * 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits) blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/ blkcg: implement interface for the unified hierarchy blkcg: misc preparations for unified hierarchy interface blkcg: separate out tg_conf_updated() from tg_set_conf() blkcg: move body parsing from blkg_conf_prep() to its callers blkcg: mark existing cftypes as legacy blkcg: rename subsystem name from blkio to io blkcg: refine error codes returned during blkcg configuration blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device() blkcg: reduce stack usage of blkg_rwstat_recursive_sum() blkcg: remove cfqg_stats->sectors blkcg: move io_service_bytes and io_serviced stats into blkcg_gq blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq blkcg: make blkcg_[rw]stat per-cpu blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it blkcg: consolidate blkg creation in blkcg_bio_issue_check() blk-throttle: improve queue bypass handling blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup() blkcg: inline [__]blkg_lookup() ...
2015-09-10mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()Kirill A. Shutemov1-2/+2
Let's use helper rather than direct check of vma->vm_ops to distinguish anonymous VMA. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10mm: make sure all file VMAs have ->vm_ops setKirill A. Shutemov1-0/+8
We rely on vma->vm_ops == NULL to detect anonymous VMA: see vma_is_anonymous(), but some drivers doesn't set ->vm_ops. As a result we can end up with anonymous page in private file mapping. That should not lead to serious misbehaviour, but nevertheless is wrong. Let's fix by setting up dummy ->vm_ops for file mmapping if f_op->mmap() didn't set its own. The patch also adds sanity check into __vma_link_rb(). It will help catch broken VMAs which inserted directly into mm_struct via insert_vm_struct(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()Oleg Nesterov2-15/+14
Add the additional "vm_flags_t vm_flags" argument to do_mmap_pgoff(), rename it to do_mmap(), and re-introduce do_mmap_pgoff() as a simple wrapper on top of do_mmap(). Perhaps we should update the callers of do_mmap_pgoff() and kill it later. This way mpx_mmap() can simply call do_mmap(vm_flags => VM_MPX) and do not play with vm internals. After this change mmap_region() has a single user outside of mmap.c, arch/tile/mm/elf.c:arch_setup_additional_pages(). It would be nice to change arch/tile/ and unexport mmap_region(). [kirill@shutemov.name: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-10kmemleak: use seq_hex_dump() to dump buffersAndy Shevchenko1-15/+6
Instead of custom approach let's use recently introduced seq_hex_dump() helper. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Joe Perches <joe@perches.com> Cc: Tadeusz Struk <tadeusz.struk@intel.com> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Tuchscherer <ingo.tuchscherer@de.ibm.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Vladimir Kondratiev <qca_vkondrat@qca.qualcomm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>