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2016-01-20fat: allow time_offset to be up to 24 hoursJan Kara
Currently we limit values of time_offset mount option to be between -12 and 12 hours. However e.g. zone GMT+12 can have a DST correction on top which makes the total time difference 13 hours. Update the checks in mount option parsing to allow offset of upto 24 hours to allow for unusual cases. Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Volker Kuhlmann <list0570@paradise.net.nz> Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20fs/hfs/catalog.c: use list_for_each_entry in hfs_cat_deleteGeliang Tang
Use list_for_each_entry() instead of list_for_each() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20epoll: add EPOLLEXCLUSIVE flagJason Baron
Currently, epoll file descriptors or epfds (the fd returned from epoll_create[1]()) that are added to a shared wakeup source are always added in a non-exclusive manner. This means that when we have multiple epfds attached to a shared fd source they are all woken up. This creates thundering herd type behavior. Introduce a new 'EPOLLEXCLUSIVE' flag that can be passed as part of the 'event' argument during an epoll_ctl() EPOLL_CTL_ADD operation. This new flag allows for exclusive wakeups when there are multiple epfds attached to a shared fd event source. The implementation walks the list of exclusive waiters, and queues an event to each epfd, until it finds the first waiter that has threads blocked on it via epoll_wait(). The idea is to search for threads which are idle and ready to process the wakeup events. Thus, we queue an event to at least 1 epfd, but may still potentially queue an event to all epfds that are attached to the shared fd source. Performance testing was done by Madars Vitolins using a modified version of Enduro/X. The use of the 'EPOLLEXCLUSIVE' flag reduce the length of this particular workload from 860s down to 24s. Sample epoll_clt text: EPOLLEXCLUSIVE Sets an exclusive wakeup mode for the epfd file descriptor that is being attached to the target file descriptor, fd. Thus, when an event occurs and multiple epfd file descriptors are attached to the same target file using EPOLLEXCLUSIVE, one or more epfds will receive an event with epoll_wait(2). The default in this scenario (when EPOLLEXCLUSIVE is not set) is for all epfds to receive an event. EPOLLEXCLUSIVE may only be specified with the op EPOLL_CTL_ADD. Signed-off-by: Jason Baron <jbaron@akamai.com> Tested-by: Madars Vitolins <m@silodev.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Eric Wong <normalperson@yhbt.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20fs/proc/task_mmu.c: add workaround for old compilersKirill A. Shutemov
For THP=n, HPAGE_PMD_NR in smaps_account() expands to BUILD_BUG(). That's fine since this codepath is eliminated by modern compilers. But older compilers have not that efficient dead code elimination. It causes problem at least with gcc 4.1.2 on m68k: fs/built-in.o: In function `smaps_account': task_mmu.c:(.text+0x4f8fa): undefined reference to `__compiletime_assert_471' Let's replace HPAGE_PMD_NR with 1 << compound_order(page). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20Merge branch 'kbuild' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild Pull kbuild updates from Michal Marek: - Make <modname>-m in makefiles work like <modname>-y and fix the fallout - Minor genksyms fix - Fix race with make -j install modules_install - Move -Wsign-compare from make W=1 to W=2 - Other minor fixes * 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild: kbuild: Demote 'sign-compare' warning to W=2 Makefile: revert "Makefile: Document ability to make file.lst and file.S" partially kbuild: Do not run modules_install and install in paralel genksyms: Handle string literals with spaces in reference files fixdep: constify strrcmp arguments ath10k: Fix build with CONFIG_THERMAL=m Revert "drm: Hack around CONFIG_AGP=m build failures" kbuild: Allow to specify composite modules with modname-m staging/ad7606: Actually build the interface modules
2016-01-19Merge branch 'for-4.5/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "We don't have a lot of core changes this time around, it's mostly in drivers, which will come in a subsequent pull. The cores changes include: - blk-mq - Prep patch from Christoph, changing blk_mq_alloc_request() to take flags instead of just using gfp_t for sleep/nosleep. - Doc patch from me, clarifying the difference between legacy and blk-mq for timer usage. - Fixes from Raghavendra for memory-less numa nodes, and a reuse of CPU masks. - Cleanup from Geliang Tang, using offset_in_page() instead of open coding it. - From Ilya, rename request_queue slab to it reflects what it holds, and a fix for proper use of bdgrab/put. - A real fix for the split across stripe boundaries from Keith. We yanked a broken version of this from 4.4-rc final, this one works. - From Mike Krinkin, emit a trace message when we split. - From Wei Tang, two small cleanups, not explicitly clearing memory that is already cleared" * 'for-4.5/core' of git://git.kernel.dk/linux-block: block: use bd{grab,put}() instead of open-coding block: split bios to max possible length block: add call to split trace point blk-mq: Avoid memoryless numa node encoded in hctx numa_node blk-mq: Reuse hardware context cpumask for tags blk-mq: add a flags parameter to blk_mq_alloc_request Revert "blk-flush: Queue through IO scheduler when flush not required" block: clarify blk_add_timer() use case for blk-mq bio: use offset_in_page macro block: do not initialise statics to 0 or NULL block: do not initialise globals to 0 or NULL block: rename request_queue slab cache
2016-01-18Merge branch 'for-linus-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs updates from Chris Mason: "This has our usual assortment of fixes and cleanups, but the biggest change included is Omar Sandoval's free space tree. It's not the default yet, mounting -o space_cache=v2 enables it and sets a readonly compat bit. The tree can actually be deleted and regenerated if there are any problems, but it has held up really well in testing so far. For very large filesystems (30T+) our existing free space caching code can end up taking a huge amount of time during commits. The new tree based code is faster and less work overall to update as the commit progresses. Omar worked on this during the summer and we'll hammer on it in production here at FB over the next few months" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (73 commits) Btrfs: fix fitrim discarding device area reserved for boot loader's use Btrfs: Check metadata redundancy on balance btrfs: statfs: report zero available if metadata are exhausted btrfs: preallocate path for snapshot creation at ioctl time btrfs: allocate root item at snapshot ioctl time btrfs: do an allocation earlier during snapshot creation btrfs: use smaller type for btrfs_path locks btrfs: use smaller type for btrfs_path lowest_level btrfs: use smaller type for btrfs_path reada btrfs: cleanup, use enum values for btrfs_path reada btrfs: constify static arrays btrfs: constify remaining structs with function pointers btrfs tests: replace whole ops structure for free space tests btrfs: use list_for_each_entry* in backref.c btrfs: use list_for_each_entry_safe in free-space-cache.c btrfs: use list_for_each_entry* in check-integrity.c Btrfs: use linux/sizes.h to represent constants btrfs: cleanup, remove stray return statements btrfs: zero out delayed node upon allocation btrfs: pass proper enum type to start_transaction() ...
2016-01-17Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: - EVM gains support for loading an x509 cert from the kernel (EVM_LOAD_X509), into the EVM trusted kernel keyring. - Smack implements 'file receive' process-based permission checking for sockets, rather than just depending on inode checks. - Misc enhancments for TPM & TPM2. - Cleanups and bugfixes for SELinux, Keys, and IMA. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits) selinux: Inode label revalidation performance fix KEYS: refcount bug fix ima: ima_write_policy() limit locking IMA: policy can be updated zero times selinux: rate-limit netlink message warnings in selinux_nlmsg_perm() selinux: export validatetrans decisions gfs2: Invalid security labels of inodes when they go invalid selinux: Revalidate invalid inode security labels security: Add hook to invalidate inode security labels selinux: Add accessor functions for inode->i_security security: Make inode argument of inode_getsecid non-const security: Make inode argument of inode_getsecurity non-const selinux: Remove unused variable in selinux_inode_init_security keys, trusted: seal with a TPM2 authorization policy keys, trusted: select hash algorithm for TPM2 chips keys, trusted: fix: *do not* allow duplicate key options tpm_ibmvtpm: properly handle interrupted packet receptions tpm_tis: Tighten IRQ auto-probing tpm_tis: Refactor the interrupt setup tpm_tis: Get rid of the duplicate IRQ probing code ...
2016-01-16fs/stat.c: drop the last new_valid_dev checkYaowei Bai
New_valid_dev() always returns true, so that's unnecessary to perform new_valid_dev() checks in some filesystems. Most checks of new_valid_dev() have been removed so let's drop this last one and then we can remove new_valid_dev() from the source code. No functional change. Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm/hugetlbfs: unmap pages if page fault raced with hole punchMike Kravetz
Page faults can race with fallocate hole punch. If a page fault happens between the unmap and remove operations, the page is not removed and remains within the hole. This is not the desired behavior. The race is difficult to detect in user level code as even in the non-race case, a page within the hole could be faulted back in before fallocate returns. If userfaultfd is expanded to support hugetlbfs in the future, this race will be easier to observe. If this race is detected and a page is mapped, the remove operation (remove_inode_hugepages) will unmap the page before removing. The unmap within remove_inode_hugepages occurs with the hugetlb_fault_mutex held so that no other faults will be processed until the page is removed. The (unmodified) routine hugetlb_vmdelete_list was moved ahead of remove_inode_hugepages to satisfy the new reference. [akpm@linux-foundation.org: move hugetlb_vmdelete_list()] Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15fs/hugetlbfs/inode.c: fix bugs in hugetlb_vmtruncate_list()Mike Kravetz
Hillf Danton noticed bugs in the hugetlb_vmtruncate_list routine. The argument end is of type pgoff_t. It was being converted to a vaddr offset and passed to unmap_hugepage_range. However, end was also being used as an argument to the vma_interval_tree_foreach controlling loop. In addition, the conversion of end to vaddr offset was incorrect. hugetlb_vmtruncate_list is called as part of a file truncate or fallocate hole punch operation. When truncating a hugetlbfs file, this bug could prevent some pages from being unmapped. This is possible if there are multiple vmas mapping the file, and there is a sufficiently sized hole between the mappings. The size of the hole between two vmas (A,B) must be such that the starting virtual address of B is greater than (ending virtual address of A << PAGE_SHIFT). In this case, the pages in B would not be unmapped. If pages are not properly unmapped during truncate, the following BUG is hit: kernel BUG at fs/hugetlbfs/inode.c:428! In the fallocate hole punch case, this bug could prevent pages from being unmapped as in the truncate case. However, for hole punch the result is that unmapped pages will not be removed during the operation. For hole punch, it is also possible that more pages than desired will be unmapped. This unnecessary unmapping will cause page faults to reestablish the mappings on subsequent page access. Fixes: 1bfad99ab (" hugetlbfs: hugetlb_vmtruncate_list() needs to take a range")Reported-by: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: <stable@vger.kernel.org> [4.3] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm: fix locking order in mm_take_all_locks()Kirill A. Shutemov
Dmitry Vyukov has reported[1] possible deadlock (triggered by his syzkaller fuzzer): Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&hugetlbfs_i_mmap_rwsem_key); lock(&mapping->i_mmap_rwsem); lock(&hugetlbfs_i_mmap_rwsem_key); lock(&mapping->i_mmap_rwsem); Both traces points to mm_take_all_locks() as a source of the problem. It doesn't take care about ordering or hugetlbfs_i_mmap_rwsem_key (aka mapping->i_mmap_rwsem for hugetlb mapping) vs. i_mmap_rwsem. huge_pmd_share() does memory allocation under hugetlbfs_i_mmap_rwsem_key and allocator can take i_mmap_rwsem if it hit reclaim. So we need to take i_mmap_rwsem from all hugetlb VMAs before taking i_mmap_rwsem from rest of VMAs. The patch also documents locking order for hugetlbfs_i_mmap_rwsem_key. [1] http://lkml.kernel.org/r/CACT4Y+Zu95tBs-0EvdiAKzUOsb4tczRRfCRTpLr4bg_OP9HuVg@mail.gmail.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Michal Hocko <mhocko@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15cgroup, memcg, writeback: drop spurious rcu locking around ↵Tejun Heo
mem_cgroup_css_from_page() In earlier versions, mem_cgroup_css_from_page() could return non-root css on a legacy hierarchy which can go away and required rcu locking; however, the eventual version simply returns the root cgroup if memcg is on a legacy hierarchy and thus doesn't need rcu locking around or in it. Remove spurious rcu lockings. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.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>
2016-01-15dax: re-enable dax pmd mappingsDan Williams
Now that the get_user_pages() path knows how to handle dax-pmd mappings, remove the protections that disabled dax-pmd support. Tests available from github.com/pmem/ndctl: make TESTS="lib/test-dax.sh lib/test-mmap.sh" check Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15dax: provide diagnostics for pmd mapping failuresDan Williams
There is a wide gamut of conditions that can trigger the dax pmd path to fallback to pte mappings. Ideally we'd have a syscall interface to determine mapping characteristics after the fact. In the meantime provide debug messages. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Suggested-by: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, dax: convert vmf_insert_pfn_pmd() to pfn_tDan Williams
Similar to the conversion of vm_insert_mixed() use pfn_t in the vmf_insert_pfn_pmd() to tag the resulting pte with _PAGE_DEVICE when the pfn is backed by a devm_memremap_pages() mapping. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, dax, gpu: convert vm_insert_mixed to pfn_tDan Williams
Convert the raw unsigned long 'pfn' argument to pfn_t for the purpose of evaluating the PFN_MAP and PFN_DEV flags. When both are set it triggers _PAGE_DEVMAP to be set in the resulting pte. There are no functional changes to the gpu drivers as a result of this conversion. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave@sr71.net> Cc: David Airlie <airlied@linux.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, dax, pmem: introduce pfn_tDan Williams
For the purpose of communicating the optional presence of a 'struct page' for the pfn returned from ->direct_access(), introduce a type that encapsulates a page-frame-number plus flags. These flags contain the historical "page_link" encoding for a scatterlist entry, but can also denote "device memory". Where "device memory" is a set of pfns that are not part of the kernel's linear mapping by default, but are accessed via the same memory controller as ram. The motivation for this new type is large capacity persistent memory that needs struct page entries in the 'memmap' to support 3rd party DMA (i.e. O_DIRECT I/O with a persistent memory source/target). However, we also need it in support of maintaining a list of mapped inodes which need to be unmapped at driver teardown or freeze_bdev() time. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave@sr71.net> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15dax: Split pmd map when fallback on COWToshi Kani
An infinite loop of PMD faults was observed when attempted to mlock() a private read-only PMD mmap'd range of a DAX file. __dax_pmd_fault() simply returns with VM_FAULT_FALLBACK when falling back to PTE on COW. However, __handle_mm_fault() returns without falling back to handle_pte_fault() because a PMD map is present in this case. Change __dax_pmd_fault() to split the PMD map, if present, before returning with VM_FAULT_FALLBACK. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15dax: fix lifetime of in-kernel dax mappings with dax_map_atomic()Dan Williams
The DAX implementation needs to protect new calls to ->direct_access() and usage of its return value against the driver for the underlying block device being disabled. Use blk_queue_enter()/blk_queue_exit() to hold off blk_cleanup_queue() from proceeding, or otherwise fail new mapping requests if the request_queue is being torn down. This also introduces blk_dax_ctl to simplify the interface from fs/dax.c through dax_map_atomic() to bdev_direct_access(). [willy@linux.intel.com: fix read() of a hole] Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jens Axboe <axboe@fb.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15dax: guarantee page aligned results from bdev_direct_access()Dan Williams
If a ->direct_access() implementation ever returns a map count less than PAGE_SIZE, catch the error in bdev_direct_access(). This simplifies error checking in upper layers. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15dax: increase granularity of dax_clear_blocks() operationsDan Williams
dax_clear_blocks is currently performing a cond_resched() after every PAGE_SIZE memset. We need not check so frequently, for example md-raid only calls cond_resched() at stripe granularity. Also, in preparation for introducing a dax_map_atomic() operation that temporarily pins a dax mapping move the call to cond_resched() to the outer loop. The worst case latency between calls to cond_resched() after this change is 500us the average latency is 133us. This is up from a 10us max and 4us average. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15pmem, dax: clean up clear_pmem()Dan Williams
To date, we have implemented two I/O usage models for persistent memory, PMEM (a persistent "ram disk") and DAX (mmap persistent memory into userspace). This series adds a third, DAX-GUP, that allows DAX mappings to be the target of direct-i/o. It allows userspace to coordinate DMA/RDMA from/to persistent memory. The implementation leverages the ZONE_DEVICE mm-zone that went into 4.3-rc1 (also discussed at kernel summit) to flag pages that are owned and dynamically mapped by a device driver. The pmem driver, after mapping a persistent memory range into the system memmap via devm_memremap_pages(), arranges for DAX to distinguish pfn-only versus page-backed pmem-pfns via flags in the new pfn_t type. The DAX code, upon seeing a PFN_DEV+PFN_MAP flagged pfn, flags the resulting pte(s) inserted into the process page tables with a new _PAGE_DEVMAP flag. Later, when get_user_pages() is walking ptes it keys off _PAGE_DEVMAP to pin the device hosting the page range active. Finally, get_page() and put_page() are modified to take references against the device driver established page mapping. Finally, this need for "struct page" for persistent memory requires memory capacity to store the memmap array. Given the memmap array for a large pool of persistent may exhaust available DRAM introduce a mechanism to allocate the memmap from persistent memory. The new "struct vmem_altmap *" parameter to devm_memremap_pages() enables arch_add_memory() to use reserved pmem capacity rather than the page allocator. This patch (of 25): Both __dax_pmd_fault, and clear_pmem() were taking special steps to clear memory a page at a time to take advantage of non-temporal clear_page() implementations. However, x86_64 does not use non-temporal instructions for clear_page(), and arch_clear_pmem() was always incurring the cost of __arch_wb_cache_pmem(). Clean up the assumption that doing clear_pmem() a page at a time is more performant. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: David Airlie <airlied@linux.ie> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jan Kara <jack@suse.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Jens Axboe <axboe@fb.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Logan Gunthorpe <logang@deltatee.com> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm: differentiate page_mapped() from page_mapcount() for compound pagesKirill A. Shutemov
Let's define page_mapped() to be true for compound pages if any sub-pages of the compound page is mapped (with PMD or PTE). On other hand page_mapcount() return mapcount for this particular small page. This will make cases like page_get_anon_vma() behave correctly once we allow huge pages to be mapped with PTE. Most users outside core-mm should use page_mapcount() instead of page_mapped(). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, thp: remove infrastructure for handling splitting PMDsKirill A. Shutemov
With new refcounting we don't need to mark PMDs splitting. Let's drop code to handle this. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, proc: adjust PSS calculationKirill A. Shutemov
The goal of this patchset is to make refcounting on THP pages cheaper with simpler semantics and allow the same THP compound page to be mapped with PMD and PTEs. This is required to get reasonable THP-pagecache implementation. With the new refcounting design it's much easier to protect against split_huge_page(): simple reference on a page will make you the deal. It makes gup_fast() implementation simpler and doesn't require special-case in futex code to handle tail THP pages. It should improve THP utilization over the system since splitting THP in one process doesn't necessary lead to splitting the page in all other processes have the page mapped. The patchset drastically lower complexity of get_page()/put_page() codepaths. I encourage people look on this code before-and-after to justify time budget on reviewing this patchset. This patch (of 37): With new refcounting all subpages of the compound page are not necessary have the same mapcount. We need to take into account mapcount of every sub-page. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15page-flags: define PG_locked behavior on compound pagesKirill A. Shutemov
lock_page() must operate on the whole compound page. It doesn't make much sense to lock part of compound page. Change code to use head page's PG_locked, if tail page is passed. This patch also gets rid of custom helper functions -- __set_page_locked() and __clear_page_locked(). They are replaced with helpers generated by __SETPAGEFLAG/__CLEARPAGEFLAG. Tail pages to these helper would trigger VM_BUG_ON(). SLUB uses PG_locked as a bit spin locked. IIUC, tail pages should never appear there. VM_BUG_ON() is added to make sure that this assumption is correct. [akpm@linux-foundation.org: fix fs/cifs/file.c] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Jérôme Glisse <jglisse@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15Merge tag 'nfsd-4.5' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
Pull nfsd updates from Bruce Fields: "Smaller bugfixes and cleanup, including a fix for a failures of kerberized NFSv4.1 mounts, and Scott Mayhew's work addressing ACK storms that can affect some high-availability NFS setups" * tag 'nfsd-4.5' of git://linux-nfs.org/~bfields/linux: nfsd: add new io class tracepoint nfsd: give up on CB_LAYOUTRECALLs after two lease periods nfsd: Fix nfsd leaks sunrpc module references lockd: constify nlmsvc_binding structure lockd: use to_delayed_work nfsd: use to_delayed_work Revert "svcrdma: Do not send XDR roundup bytes for a write chunk" lockd: Register callbacks on the inetaddr_chain and inet6addr_chain nfsd: Register callbacks on the inetaddr_chain and inet6addr_chain sunrpc: Add a function to close temporary transports immediately nfsd: don't base cl_cb_status on stale information nfsd4: fix gss-proxy 4.1 mounts for some AD principals nfsd: fix unlikely NULL deref in mach_creds_match nfsd: minor consolidation of mach_cred handling code nfsd: helper for dup of possibly NULL string svcrpc: move some initialization to common code nfsd: fix a warning message nfsd: constify nfsd4_callback_ops structure nfsd: recover: constify nfsd4_client_tracking_ops structures svcrdma: Do not send XDR roundup bytes for a write chunk
2016-01-15Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull UDF fixes and quota cleanups from Jan Kara: "Several UDF fixes and some minor quota cleanups" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: udf: Check output buffer length when converting name to CS0 udf: Prevent buffer overrun with multi-byte characters quota: constify qtree_fmt_operations structures udf: avoid uninitialized variable use udf: Fix lost indirect extent block udf: Factor out code for creating indirect extent udf: limit the maximum number of indirect extents in a row udf: limit the maximum number of TD redirections fs: make quota/dquot.c explicitly non-modular fs: make quota/netlink.c explicitly non-modular
2016-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge first patch-bomb from Andrew Morton: - A few hotfixes which missed 4.4 becasue I was asleep. cc'ed to -stable - A few misc fixes - OCFS2 updates - Part of MM. Including pretty large changes to page-flags handling and to thp management which have been buffered up for 2-3 cycles now. I have a lot of MM material this time. [ It turns out the THP part wasn't quite ready, so that got dropped from this series - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) zsmalloc: reorganize struct size_class to pack 4 bytes hole mm/zbud.c: use list_last_entry() instead of list_tail_entry() zram/zcomp: do not zero out zcomp private pages zram: pass gfp from zcomp frontend to backend zram: try vmalloc() after kmalloc() zram/zcomp: use GFP_NOIO to allocate streams mm: add tracepoint for scanning pages drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64 mm/page_isolation: use macro to judge the alignment mm: fix noisy sparse warning in LIBCFS_ALLOC_PRE() mm: rework virtual memory accounting include/linux/memblock.h: fix ordering of 'flags' argument in comments mm: move lru_to_page to mm_inline.h Documentation/filesystems: describe the shared memory usage/accounting memory-hotplug: don't BUG() in register_memory_resource() hugetlb: make mm and fs code explicitly non-modular mm/swapfile.c: use list_for_each_entry_safe in free_swap_count_continuations mm: /proc/pid/clear_refs: no need to clear VM_SOFTDIRTY in clear_soft_dirty_pmd() mm: make sure isolate_lru_page() is never called for tail page vmstat: make vmstat_updater deferrable again and shut down on idle ...
2016-01-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial Pull trivial tree updates from Jiri Kosina. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: floppy: make local variable non-static exynos: fixes an incorrect header guard dt-bindings: fixes some incorrect header guards cpufreq-dt: correct dead link in documentation cpufreq: ARM big LITTLE: correct dead link in documentation treewide: Fix typos in printk Documentation: filesystem: Fix typo in fs/eventfd.c fs/super.c: use && instead of & for warn_on condition Documentation: fix sysfs-ptp lib: scatterlist: fix Kconfig description
2016-01-14Merge tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client updates from Trond Myklebust: "Highlights include: Stable fixes: - Fix a regression in the SunRPC socket polling code - Fix the attribute cache revalidation code - Fix race in __update_open_stateid() - Fix an lo->plh_block_lgets imbalance in layoutreturn - Fix an Oopsable typo in ff_mirror_match_fh() Features: - pNFS layout recall performance improvements. - pNFS/flexfiles: Support server-supplied layoutstats sampling period Bugfixes + cleanups: - NFSv4: Don't perform cached access checks before we've OPENed the file - Fix starvation issues with background flushes - Reclaim writes should be flushed as unstable writes if there are already entries in the commit lists - Various bugfixes from Chuck to fix NFS/RDMA send queue ordering problems - Ensure that we propagate fatal layoutget errors back to the application - Fixes for sundry flexfiles layoutstats bugs - Fix files/flexfiles to not cache invalidated layouts in the DS commit buckets" * tag 'nfs-for-4.5-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (68 commits) NFS: Fix a compile warning about unused variable in nfs_generic_pg_pgios() NFSv4: Fix a compile warning about no prototype for nfs4_ioctl() NFS: Use wait_on_atomic_t() for unlock after readahead SUNRPC: Fixup socket wait for memory NFSv4.1/pNFS: Cleanup constify struct pnfs_layout_range arguments NFSv4.1/pnfs: Cleanup copying of pnfs_layout_range structures NFSv4.1/pNFS: Cleanup pnfs_mark_matching_lsegs_invalid() NFSv4.1/pNFS: Fix a race in initiate_file_draining() NFSv4.1/pNFS: pnfs_error_mark_layout_for_return() must always return layout NFSv4.1/pNFS: pnfs_mark_matching_lsegs_return() should set the iomode NFSv4.1/pNFS: Use nfs4_stateid_copy for copying stateids NFSv4.1/pNFS: Don't pass stateids by value to pnfs_send_layoutreturn() NFS: Relax requirements in nfs_flush_incompatible NFSv4.1/pNFS: Don't queue up a new commit if the layout segment is invalid NFS: Allow multiple commit requests in flight per file NFS/pNFS: Fix up pNFS write reschedule layering violations and bugs SUNRPC: Fix a missing break in rpc_anyaddr() pNFS/flexfiles: Fix an Oopsable typo in ff_mirror_match_fh() NFS: Fix attribute cache revalidation NFS: Ensure we revalidate attributes before using execute_ok() ...
2016-01-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fix from Al Viro: "Don't put symlink bodies in pagecache into highmem" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Make sure that highmem pages are not added to symlink page cache
2016-01-14mm: rework virtual memory accountingKonstantin Khlebnikov
When inspecting a vague code inside prctl(PR_SET_MM_MEM) call (which testing the RLIMIT_DATA value to figure out if we're allowed to assign new @start_brk, @brk, @start_data, @end_data from mm_struct) it's been commited that RLIMIT_DATA in a form it's implemented now doesn't do anything useful because most of user-space libraries use mmap() syscall for dynamic memory allocations. Linus suggested to convert RLIMIT_DATA rlimit into something suitable for anonymous memory accounting. But in this patch we go further, and the changes are bundled together as: * keep vma counting if CONFIG_PROC_FS=n, will be used for limits * replace mm->shared_vm with better defined mm->data_vm * account anonymous executable areas as executable * account file-backed growsdown/up areas as stack * drop struct file* argument from vm_stat_account * enforce RLIMIT_DATA for size of data areas This way code looks cleaner: now code/stack/data classification depends only on vm_flags state: VM_EXEC & ~VM_WRITE -> code (VmExe + VmLib in proc) VM_GROWSUP | VM_GROWSDOWN -> stack (VmStk) VM_WRITE & ~VM_SHARED & !stack -> data (VmData) The rest (VmSize - VmData - VmStk - VmExe - VmLib) could be called "shared", but that might be strange beast like readonly-private or VM_IO area. - RLIMIT_AS limits whole address space "VmSize" - RLIMIT_STACK limits stack "VmStk" (but each vma individually) - RLIMIT_DATA now limits "VmData" Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Willy Tarreau <w@1wt.eu> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Kees Cook <keescook@google.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14hugetlb: make mm and fs code explicitly non-modularPaul Gortmaker
The Kconfig currently controlling compilation of this code is: config HUGETLBFS bool "HugeTLB file system support" ...meaning that it currently is not being built as a module by anyone. Lets remove the modular code that is essentially orphaned, so that when reading the driver there is no doubt it is builtin-only. Since module_init translates to device_initcall in the non-modular case, the init ordering gets moved to earlier levels when we use the more appropriate initcalls here. Originally I had the fs part and the mm part as separate commits, just by happenstance of the nature of how I detected these non-modular use cases. But that can possibly introduce regressions if the patch merge ordering puts the fs part 1st -- as the 0-day testing reported a splat at mount time. Investigating with "initcall_debug" showed that the delta was init_hugetlbfs_fs being called _before_ hugetlb_init instead of after. So both the fs change and the mm change are here together. In addition, it worked before due to luck of link order, since they were both in the same initcall category. So we now have the fs part using fs_initcall, and the mm part using subsys_initcall, which puts it one bucket earlier. It now passes the basic sanity test that failed in earlier 0-day testing. We delete the MODULE_LICENSE tag and capture that information at the top of the file alongside author comments, etc. We don't replace module.h with init.h since the file already has that. Also note that MODULE_ALIAS is a no-op for non-modular code. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Reported-by: kernel test robot <ying.huang@linux.intel.com> Cc: Nadia Yvette Chambers <nyc@holomorphy.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Acked-by: Davidlohr Bueso <dave@stgolabs.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm: /proc/pid/clear_refs: no need to clear VM_SOFTDIRTY in ↵Oleg Nesterov
clear_soft_dirty_pmd() clear_soft_dirty_pmd() is called by clear_refs_write(CLEAR_REFS_SOFT_DIRTY), VM_SOFTDIRTY was already cleared before walk_page_range(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14proc: meminfo: estimate available memory more conservativelyJohannes Weiner
The MemAvailable item in /proc/meminfo is to give users a hint of how much memory is allocatable without causing swapping, so it excludes the zones' low watermarks as unavailable to userspace. However, for a userspace allocation, kswapd will actually reclaim until the free pages hit a combination of the high watermark and the page allocator's lowmem protection that keeps a certain amount of DMA and DMA32 memory from userspace as well. Subtract the full amount we know to be unavailable to userspace from the number of free pages when calculating MemAvailable. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> 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>
2016-01-14fs/block_dev.c:bdev_write_page(): use blk_queue_enter(..., GFP_NOIO)Andrew Morton
bdev_write_page() is used by swapout and by writepage where we cannot use __GFP_FS or __GFP_IO. So it is misleading to mention GFP_KERNEL here. blk_queue_enter() only actually looks at __GFP_DIRECT_RECLAIM, so no bugs were harmed in the making of this patch. Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jens Axboe <axboe@fb.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, procfs: breakdown RSS for anon, shmem and file in /proc/pid/statusJerome Marchand
There are several shortcomings with the accounting of shared memory (SysV shm, shared anonymous mapping, mapping of a tmpfs file). The values in /proc/<pid>/status and <...>/statm don't allow to distinguish between shmem memory and a shared mapping to a regular file, even though theirs implication on memory usage are quite different: during reclaim, file mapping can be dropped or written back on disk, while shmem needs a place in swap. Also, to distinguish the memory occupied by anonymous and file mappings, one has to read the /proc/pid/statm file, which has a field for the file mappings (again, including shmem) and total memory occupied by these mappings (i.e. equivalent to VmRSS in the <...>/status file. Getting the value for anonymous mappings only is thus not exactly user-friendly (the statm file is intended to be rather efficiently machine-readable). To address both of these shortcomings, this patch adds a breakdown of VmRSS in /proc/<pid>/status via new fields RssAnon, RssFile and RssShmem, making use of the previous preparatory patch. These fields tell the user the memory occupied by private anonymous pages, mapped regular files and shmem, respectively. Other existing fields in /status and /statm files are left without change. The /statm file can be extended in the future, if there's a need for that. Example (part of) /proc/pid/status output including the new Rss* fields: VmPeak: 2001008 kB VmSize: 2001004 kB VmLck: 0 kB VmPin: 0 kB VmHWM: 5108 kB VmRSS: 5108 kB RssAnon: 92 kB RssFile: 1324 kB RssShmem: 3692 kB VmData: 192 kB VmStk: 136 kB VmExe: 4 kB VmLib: 1784 kB VmPTE: 3928 kB VmPMD: 20 kB VmSwap: 0 kB HugetlbPages: 0 kB [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, shmem: add internal shmem resident memory accountingJerome Marchand
Currently looking at /proc/<pid>/status or statm, there is no way to distinguish shmem pages from pages mapped to a regular file (shmem pages are mapped to /dev/zero), even though their implication in actual memory use is quite different. The internal accounting currently counts shmem pages together with regular files. As a preparation to extend the userspace interfaces, this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for shmem pages separately from MM_FILEPAGES. The next patch will expose it to userspace - this patch doesn't change the exported values yet, by adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was used before. The only user-visible change after this patch is the OOM killer message that separates the reported "shmem-rss" from "file-rss". [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm, proc: reduce cost of /proc/pid/smaps for unpopulated shmem mappingsVlastimil Babka
Following the previous patch, further reduction of /proc/pid/smaps cost is possible for private writable shmem mappings with unpopulated areas where the page walk invokes the .pte_hole function. We can use radix tree iterator for each such area instead of calling find_get_entry() in a loop. This is possible at the extra maintenance cost of introducing another shmem function shmem_partial_swap_usage(). To demonstrate the diference, I have measured this on a process that creates a private writable 2GB mapping of a partially swapped out /dev/shm/file (which cannot employ the optimizations from the prvious patch) and doesn't populate it at all. I time how long does it take to cat /proc/pid/smaps of this process 100 times. Before this patch: real 0m3.831s user 0m0.180s sys 0m3.212s After this patch: real 0m1.176s user 0m0.180s sys 0m0.684s The time is similar to the case where a radix tree iterator is employed on the whole mapping. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> 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>
2016-01-14mm, proc: reduce cost of /proc/pid/smaps for shmem mappingsVlastimil Babka
The previous patch has improved swap accounting for shmem mapping, which however made /proc/pid/smaps more expensive for shmem mappings, as we consult the radix tree for each pte_none entry, so the overal complexity is O(n*log(n)). We can reduce this significantly for mappings that cannot contain COWed pages, because then we can either use the statistics tha shmem object itself tracks (if the mapping contains the whole object, or the swap usage of the whole object is zero), or use the radix tree iterator, which is much more effective than repeated find_get_entry() calls. This patch therefore introduces a function shmem_swap_usage(vma) and makes /proc/pid/smaps use it when possible. Only for writable private mappings of shmem objects (i.e. tmpfs files) with the shmem object itself (partially) swapped outwe have to resort to the find_get_entry() approach. Hopefully such mappings are relatively uncommon. To demonstrate the diference, I have measured this on a process that creates a 2GB mapping and dirties single pages with a stride of 2MB, and time how long does it take to cat /proc/pid/smaps of this process 100 times. Private writable mapping of a /dev/shm/file (the most complex case): real 0m3.831s user 0m0.180s sys 0m3.212s Shared mapping of an almost full mapping of a partially swapped /dev/shm/file (which needs to employ the radix tree iterator). real 0m1.351s user 0m0.096s sys 0m0.768s Same, but with /dev/shm/file not swapped (so no radix tree walk needed) real 0m0.935s user 0m0.128s sys 0m0.344s Private anonymous mapping: real 0m0.949s user 0m0.116s sys 0m0.348s The cost is now much closer to the private anonymous mapping case, unless the shmem mapping is private and writable. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> 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>
2016-01-14mm, proc: account for shmem swap in /proc/pid/smapsVlastimil Babka
Currently, /proc/pid/smaps will always show "Swap: 0 kB" for shmem-backed mappings, even if the mapped portion does contain pages that were swapped out. This is because unlike private anonymous mappings, shmem does not change pte to swap entry, but pte_none when swapping the page out. In the smaps page walk, such page thus looks like it was never faulted in. This patch changes smaps_pte_entry() to determine the swap status for such pte_none entries for shmem mappings, similarly to how mincore_page() does it. Swapped out shmem pages are thus accounted for. For private mappings of tmpfs files that COWed some of the pages, swaped out status of the original shmem pages is naturally ignored. If some of the private copies was also swapped out, they are accounted via their page table swap entries, so the resulting reported swap usage is then a sum of both swapped out private copies, and swapped out shmem pages that were not COWed. No double accounting can thus happen. The accounting is arguably still not as precise as for private anonymous mappings, since now we will count also pages that the process in question never accessed, but another process populated them and then let them become swapped out. I believe it is still less confusing and subtle than not showing any swap usage by shmem mappings at all. Swapped out counter might of interest of users who would like to prevent from future swapins during performance critical operation and pre-fault them at their convenience. Especially for larger swapped out regions the cost of swapin is much higher than a fresh page allocation. So a differentiation between pte_none vs. swapped out is important for those usecases. One downside of this patch is that it makes /proc/pid/smaps more expensive for shmem mappings, as we consult the radix tree for each pte_none entry, so the overal complexity is O(n*log(n)). I have measured this on a process that creates a 2GB mapping and dirties single pages with a stride of 2MB, and time how long does it take to cat /proc/pid/smaps of this process 100 times. Private anonymous mapping: real 0m0.949s user 0m0.116s sys 0m0.348s Mapping of a /dev/shm/file: real 0m3.831s user 0m0.180s sys 0m3.212s The difference is rather substantial, so the next patch will reduce the cost for shared or read-only mappings. In a less controlled experiment, I've gathered pids of processes on my desktop that have either '/dev/shm/*' or 'SYSV*' in smaps. This included the Chrome browser and some KDE processes. Again, I've run cat /proc/pid/smaps on each 100 times. Before this patch: real 0m9.050s user 0m0.518s sys 0m8.066s After this patch: real 0m9.221s user 0m0.541s sys 0m8.187s This suggests low impact on average systems. Note that this patch doesn't attempt to adjust the SwapPss field for shmem mappings, which would need extra work to determine who else could have the pages mapped. Thus the value stays zero except for COWed swapped out pages in a shmem mapping, which are accounted as usual. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Jerome Marchand <jmarchan@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14mm/mempolicy.c: convert the shared_policy lock to a rwlockNathan Zimmer
When running the SPECint_rate gcc on some very large boxes it was noticed that the system was spending lots of time in mpol_shared_policy_lookup(). The gamess benchmark can also show it and is what I mostly used to chase down the issue since the setup for that I found to be easier. To be clear the binaries were on tmpfs because of disk I/O requirements. We then used text replication to avoid icache misses and having all the copies banging on the memory where the instruction code resides. This results in us hitting a bottleneck in mpol_shared_policy_lookup() since lookup is serialised by the shared_policy lock. I have only reproduced this on very large (3k+ cores) boxes. The problem starts showing up at just a few hundred ranks getting worse until it threatens to livelock once it gets large enough. For example on the gamess benchmark at 128 ranks this area consumes only ~1% of time, at 512 ranks it consumes nearly 13%, and at 2k ranks it is over 90%. To alleviate the contention in this area I converted the spinlock to an rwlock. This allows a large number of lookups to happen simultaneously. The results were quite good reducing this consumtion at max ranks to around 2%. [akpm@linux-foundation.org: tidy up code comments] Signed-off-by: Nathan Zimmer <nzimmer@sgi.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Nadia Yvette Chambers <nyc@holomorphy.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14kmemcg: account certain kmem allocations to memcgVladimir Davydov
Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.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>
2016-01-14Revert "kernfs: do not account ino_ida allocations to memcg"Vladimir Davydov
Currently, all kmem allocations (namely every kmem_cache_alloc, kmalloc, alloc_kmem_pages call) are accounted to memory cgroup automatically. Callers have to explicitly opt out if they don't want/need accounting for some reason. Such a design decision leads to several problems: - kmalloc users are highly sensitive to failures, many of them implicitly rely on the fact that kmalloc never fails, while memcg makes failures quite plausible. - A lot of objects are shared among different containers by design. Accounting such objects to one of containers is just unfair. Moreover, it might lead to pinning a dead memcg along with its kmem caches, which aren't tiny, which might result in noticeable increase in memory consumption for no apparent reason in the long run. - There are tons of short-lived objects. Accounting them to memcg will only result in slight noise and won't change the overall picture, but we still have to pay accounting overhead. For more info, see - http://lkml.kernel.org/r/20151105144002.GB15111%40dhcp22.suse.cz - http://lkml.kernel.org/r/20151106090555.GK29259@esperanza Therefore this patchset switches to the white list policy. Now kmalloc users have to explicitly opt in by passing __GFP_ACCOUNT flag. Currently, the list of accounted objects is quite limited and only includes those allocations that (1) are known to be easily triggered from userspace and (2) can fail gracefully (for the full list see patch no. 6) and it still misses many object types. However, accounting only those objects should be a satisfactory approximation of the behavior we used to have for most sane workloads. This patch (of 6): Revert 499611ed451508a42d1d7d ("kernfs: do not account ino_ida allocations to memcg"). Black-list kmem accounting policy (aka __GFP_NOACCOUNT) turned out to be fragile and difficult to maintain, because there seem to be many more allocations that should not be accounted than those that should be. Besides, false accounting an allocation might result in much worse consequences than not accounting at all, namely increased memory consumption due to pinned dead kmem caches. So it was decided to switch to the white-list policy. This patch reverts bits introducing the black-list policy. The white-list policy will be introduced later in the series. Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.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>
2016-01-14ocfs2/dlm: cleanup redunant lksb flags in dlmcommon.hJoseph Qi
lksb flags are defined both in dlmapi.h and dlmcommon.h. So clean them up from dlmcommon.h. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Jiufei Xue <xuejiufei@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14ocfs2: dlm: remove redundant codeJunxiao Bi
Found this when do patch review, remove to make it clear and save a little cpu time. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14ocfs2: access orphan dinode before delete entry in ocfs2_orphan_delJoseph Qi
In ocfs2_orphan_del, currently it finds and deletes entry first, and then access orphan dir dinode. This will have a problem once ocfs2_journal_access_di fails. In this case, entry will be removed from orphan dir, but in deed the inode hasn't been deleted successfully. In other words, the file is missing but not actually deleted. So we should access orphan dinode first like unlink and rename. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Jiufei Xue <xuejiufei@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14ocfs2/dlm: do not insert a new mle when another process is already migratingxuejiufei
When two processes are migrating the same lockres, dlm_add_migration_mle() return -EEXIST, but insert a new mle in hash list. dlm_migrate_lockres() will detach the old mle and free the new one which is already in hash list, that will destroy the list. Signed-off-by: Jiufei Xue <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Reviewed-by: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>