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* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2016-07-26186-4134/+7363
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - a few misc bits - ocfs2 - most(?) of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (125 commits) thp: fix comments of __pmd_trans_huge_lock() cgroup: remove unnecessary 0 check from css_from_id() cgroup: fix idr leak for the first cgroup root mm: memcontrol: fix documentation for compound parameter mm: memcontrol: remove BUG_ON in uncharge_list mm: fix build warnings in <linux/compaction.h> mm, thp: convert from optimistic swapin collapsing to conservative mm, thp: fix comment inconsistency for swapin readahead functions thp: update Documentation/{vm/transhuge,filesystems/proc}.txt shmem: split huge pages beyond i_size under memory pressure thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHE khugepaged: add support of collapse for tmpfs/shmem pages shmem: make shmem_inode_info::lock irq-safe khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page() thp: extract khugepaged from mm/huge_memory.c shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappings shmem: add huge pages support shmem: get_unmapped_area align huge page shmem: prepare huge= mount option and sysfs knob mm, rmap: account shmem thp pages ...
| * thp: fix comments of __pmd_trans_huge_lock()Huang Ying2016-07-261-3/+3
| | | | | | | | | | | | | | | | | | | | To make the comments consistent with the already changed code. Link: http://lkml.kernel.org/r/1466200004-6196-1-git-send-email-ying.huang@intel.com Signed-off-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * cgroup: remove unnecessary 0 check from css_from_id()Johannes Weiner2016-07-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | css_idr allocation starts at 1, so index 0 will never point to an item. css_from_id() currently filters that before asking idr_find(), but idr_find() would also just return NULL, so this is not needed. Link: http://lkml.kernel.org/r/20160617162427.GC19084@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Tejun Heo <tj@kernel.org> Cc: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * cgroup: fix idr leak for the first cgroup rootJohannes Weiner2016-07-261-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The valid cgroup hierarchy ID range includes 0, so we can't filter for positive numbers when freeing it, or it'll leak the first ID. No big deal, just disruptive when reading the code. The ID is freed during error handling and when the reference count hits zero, so the double-free test is not necessary; remove it. Link: http://lkml.kernel.org/r/20160617162359.GB19084@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Tejun Heo <tj@kernel.org> Cc: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: memcontrol: fix documentation for compound parameterLi RongQing2016-07-261-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit f627c2f53786 ("memcg: adjust to support new THP refcounting") adds a compound parameter for several functions, and change one as compound for mem_cgroup_move_account but it does not change the comments. Link: http://lkml.kernel.org/r/1465368216-9393-1-git-send-email-roy.qing.li@gmail.com Signed-off-by: Li RongQing <roy.qing.li@gmail.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>
| * mm: memcontrol: remove BUG_ON in uncharge_listLi RongQing2016-07-261-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When calling uncharge_list, if a page is transparent huge we don't need to BUG_ON about non-transparent huge, since nobody should be able to see the page at this stage and this page cannot be raced against with a THP split. This check became unneeded after 0a31bc97c80c ("mm: memcontrol: rewrite uncharge API"). [mhocko@suse.com: changelog enhancements] Link: http://lkml.kernel.org/r/1465369248-13865-1-git-send-email-roy.qing.li@gmail.com Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: fix build warnings in <linux/compaction.h>Minchan Kim2016-07-266-26/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Randy reported below build error. > In file included from ../include/linux/balloon_compaction.h:48:0, > from ../mm/balloon_compaction.c:11: > ../include/linux/compaction.h:237:51: warning: 'struct node' declared inside parameter list [enabled by default] > static inline int compaction_register_node(struct node *node) > ../include/linux/compaction.h:237:51: warning: its scope is only this definition or declaration, which is probably not what you want [enabled by default] > ../include/linux/compaction.h:242:54: warning: 'struct node' declared inside parameter list [enabled by default] > static inline void compaction_unregister_node(struct node *node) > It was caused by non-lru page migration which needs compaction.h but compaction.h doesn't include any header to be standalone. I think proper header for non-lru page migration is migrate.h rather than compaction.h because migrate.h has already headers needed to work non-lru page migration indirectly like isolate_mode_t, migrate_mode MIGRATEPAGE_SUCCESS. [akpm@linux-foundation.org: revert mm-balloon-use-general-non-lru-movable-page-feature-fix.patch temp fix] Link: http://lkml.kernel.org/r/20160610003304.GE29779@bbox Signed-off-by: Minchan Kim <minchan@kernel.org> Reported-by: Randy Dunlap <rdunlap@infradead.org> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Gioh Kim <gi-oh.kim@profitbricks.com> Cc: Rafael Aquini <aquini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: convert from optimistic swapin collapsing to conservativeEbru Akagunduz2016-07-262-23/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To detect whether khugepaged swapin is worthwhile, this patch checks the amount of young pages. There should be at least half of HPAGE_PMD_NR to swapin. Link: http://lkml.kernel.org/r/1468109451-1615-1-git-send-email-ebru.akagunduz@gmail.com Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Suggested-by: Minchan Kim <minchan@kernel.org> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: fix comment inconsistency for swapin readahead functionsEbru Akagunduz2016-07-261-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After fixing swapin issues, comment lines stayed as in old version. This patch updates the comments. Link: http://lkml.kernel.org/r/1468109345-32258-1-git-send-email-ebru.akagunduz@gmail.com Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Boaz Harrosh <boaz@plexistor.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: update Documentation/{vm/transhuge,filesystems/proc}.txtKirill A. Shutemov2016-07-262-36/+101
| | | | | | | | | | | | | | | | | | Add info about tmpfs/shmem with huge pages. Link: http://lkml.kernel.org/r/1466021202-61880-38-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem: split huge pages beyond i_size under memory pressureKirill A. Shutemov2016-07-262-1/+180
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Even if user asked to allocate huge pages always (huge=always), we should be able to free up some memory by splitting pages which are partly byound i_size if memory presure comes or once we hit limit on filesystem size (-o size=). In order to do this we maintain per-superblock list of inodes, which potentially have huge pages on the border of file size. Per-fs shrinker can reclaim memory by splitting such pages. If we hit -ENOSPC during shmem_getpage_gfp(), we try to split a page to free up space on the filesystem and retry allocation if it succeed. Link: http://lkml.kernel.org/r/1466021202-61880-37-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: introduce CONFIG_TRANSPARENT_HUGE_PAGECACHEKirill A. Shutemov2016-07-266-21/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | For file mappings, we don't deposit page tables on THP allocation because it's not strictly required to implement split_huge_pmd(): we can just clear pmd and let following page faults to reconstruct the page table. But Power makes use of deposited page table to address MMU quirk. Let's hide THP page cache, including huge tmpfs, under separate config option, so it can be forbidden on Power. We can revert the patch later once solution for Power found. Link: http://lkml.kernel.org/r/1466021202-61880-36-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> 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>
| * khugepaged: add support of collapse for tmpfs/shmem pagesKirill A. Shutemov2016-07-264-17/+500
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch extends khugepaged to support collapse of tmpfs/shmem pages. We share fair amount of infrastructure with anon-THP collapse. Few design points: - First we are looking for VMA which can be suitable for mapping huge page; - If the VMA maps shmem file, the rest scan/collapse operations operates on page cache, not on page tables as in anon VMA case. - khugepaged_scan_shmem() finds a range which is suitable for huge page. The scan is lockless and shouldn't disturb system too much. - once the candidate for collapse is found, collapse_shmem() attempts to create a huge page: + scan over radix tree, making the range point to new huge page; + new huge page is not-uptodate, locked and freezed (refcount is 0), so nobody can touch them until we say so. + we swap in pages during the scan. khugepaged_scan_shmem() filters out ranges with more than khugepaged_max_ptes_swap swapped out pages. It's HPAGE_PMD_NR/8 by default. + old pages are isolated, unmapped and put to local list in case to be restored back if collapse failed. - if collapse succeed, we retract pte page tables from VMAs where huge pages mapping is possible. The huge page will be mapped as PMD on next minor fault into the range. Link: http://lkml.kernel.org/r/1466021202-61880-35-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem: make shmem_inode_info::lock irq-safeKirill A. Shutemov2016-07-262-26/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are going to need to call shmem_charge() under tree_lock to get accoutning right on collapse of small tmpfs pages into a huge one. The problem is that tree_lock is irq-safe and lockdep is not happy, that we take irq-unsafe lock under irq-safe[1]. Let's convert the lock to irq-safe. [1] https://gist.github.com/kiryl/80c0149e03ed35dfaf26628b8e03cdbc Link: http://lkml.kernel.org/r/1466021202-61880-34-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * khugepaged: move up_read(mmap_sem) out of khugepaged_alloc_page()Kirill A. Shutemov2016-07-261-15/+10
| | | | | | | | | | | | | | | | | | | | Both variants of khugepaged_alloc_page() do up_read(&mm->mmap_sem) first: no point keep it inside the function. Link: http://lkml.kernel.org/r/1466021202-61880-33-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: extract khugepaged from mm/huge_memory.cKirill A. Shutemov2016-07-265-1485/+1515
| | | | | | | | | | | | | | | | | | | | | | | | khugepaged implementation grew to the point when it deserve separate file in source. Let's move it to mm/khugepaged.c. Link: http://lkml.kernel.org/r/1466021202-61880-32-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem, thp: respect MADV_{NO,}HUGEPAGE for file mappingsKirill A. Shutemov2016-07-262-17/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's wire up existing madvise() hugepage hints for file mappings. MADV_HUGEPAGE advise shmem to allocate huge page on page fault in the VMA. It only has effect if the filesystem is mounted with huge=advise or huge=within_size. MADV_NOHUGEPAGE prevents hugepage from being allocated on page fault in the VMA. It doesn't prevent a huge page from being allocated by other means, i.e. page fault into different mapping or write(2) into file. Link: http://lkml.kernel.org/r/1466021202-61880-31-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem: add huge pages supportKirill A. Shutemov2016-07-269-70/+331
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Here's basic implementation of huge pages support for shmem/tmpfs. It's all pretty streight-forward: - shmem_getpage() allcoates huge page if it can and try to inserd into radix tree with shmem_add_to_page_cache(); - shmem_add_to_page_cache() puts the page onto radix-tree if there's space for it; - shmem_undo_range() removes huge pages, if it fully within range. Partial truncate of huge pages zero out this part of THP. This have visible effect on fallocate(FALLOC_FL_PUNCH_HOLE) behaviour. As we don't really create hole in this case, lseek(SEEK_HOLE) may have inconsistent results depending what pages happened to be allocated. - no need to change shmem_fault: core-mm will map an compound page as huge if VMA is suitable; Link: http://lkml.kernel.org/r/1466021202-61880-30-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem: get_unmapped_area align huge pageHugh Dickins2016-07-265-4/+142
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Provide a shmem_get_unmapped_area method in file_operations, called at mmap time to decide the mapping address. It could be conditional on CONFIG_TRANSPARENT_HUGEPAGE, but save #ifdefs in other places by making it unconditional. shmem_get_unmapped_area() first calls the usual mm->get_unmapped_area (which we treat as a black box, highly dependent on architecture and config and executable layout). Lots of conditions, and in most cases it just goes with the address that chose; but when our huge stars are rightly aligned, yet that did not provide a suitable address, go back to ask for a larger arena, within which to align the mapping suitably. There have to be some direct calls to shmem_get_unmapped_area(), not via the file_operations: because of the way shmem_zero_setup() is called to create a shmem object late in the mmap sequence, when MAP_SHARED is requested with MAP_ANONYMOUS or /dev/zero. Though this only matters when /proc/sys/vm/shmem_huge has been set. Link: http://lkml.kernel.org/r/1466021202-61880-29-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * shmem: prepare huge= mount option and sysfs knobKirill A. Shutemov2016-07-264-1/+168
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds new mount option "huge=". It can have following values: - "always": Attempt to allocate huge pages every time we need a new page; - "never": Do not allocate huge pages; - "within_size": Only allocate huge page if it will be fully within i_size. Also respect fadvise()/madvise() hints; - "advise: Only allocate huge pages if requested with fadvise()/madvise(); Default is "never" for now. "mount -o remount,huge= /mountpoint" works fine after mount: remounting huge=never will not attempt to break up huge pages at all, just stop more from being allocated. No new config option: put this under CONFIG_TRANSPARENT_HUGEPAGE, which is the appropriate option to protect those who don't want the new bloat, and with which we shall share some pmd code. Prohibit the option when !CONFIG_TRANSPARENT_HUGEPAGE, just as mpol is invalid without CONFIG_NUMA (was hidden in mpol_parse_str(): make it explicit). Allow enabling THP only if the machine has_transparent_hugepage(). But what about Shmem with no user-visible mount? SysV SHM, memfds, shared anonymous mmaps (of /dev/zero or MAP_ANONYMOUS), GPU drivers' DRM objects, Ashmem. Though unlikely to suit all usages, provide sysfs knob /sys/kernel/mm/transparent_hugepage/shmem_enabled to experiment with huge on those. And allow shmem_enabled two further values: - "deny": For use in emergencies, to force the huge option off from all mounts; - "force": Force the huge option on for all - very useful for testing; Based on patch by Hugh Dickins. Link: http://lkml.kernel.org/r/1466021202-61880-28-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, rmap: account shmem thp pagesKirill A. Shutemov2016-07-268-15/+58
| | | | | | | | | | | | | | | | | | | | | | | | Let's add ShmemHugePages and ShmemPmdMapped fields into meminfo and smaps. It indicates how many times we allocate and map shmem THP. NR_ANON_TRANSPARENT_HUGEPAGES is renamed to NR_ANON_THPS. Link: http://lkml.kernel.org/r/1466021202-61880-27-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * truncate: handle file thpKirill A. Shutemov2016-07-261-5/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | For shmem/tmpfs we only need to tweak truncate_inode_page() and invalidate_mapping_pages(). truncate_inode_pages_range() and invalidate_inode_pages2_range() are adjusted to use page_to_pgoff(). Link: http://lkml.kernel.org/r/1466021202-61880-26-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * filemap: prepare find and delete operations for huge pagesKirill A. Shutemov2016-07-261-56/+122
| | | | | | | | | | | | | | | | | | | | | | | | | | | | For now, we would have HPAGE_PMD_NR entries in radix tree for every huge page. That's suboptimal and it will be changed to use Matthew's multi-order entries later. 'add' operation is not changed, because we don't need it to implement hugetmpfs: shmem uses its own implementation. Link: http://lkml.kernel.org/r/1466021202-61880-25-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * radix-tree: implement radix_tree_maybe_preload_order()Kirill A. Shutemov2016-07-262-5/+80
| | | | | | | | | | | | | | | | | | | | | | | | | | The new helper is similar to radix_tree_maybe_preload(), but tries to preload number of nodes required to insert (1 << order) continuous naturally-aligned elements. This is required to push huge pages into pagecache. Link: http://lkml.kernel.org/r/1466021202-61880-24-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * page-flags: relax policy for PG_mappedtodisk and PG_reclaimKirill A. Shutemov2016-07-261-3/+3
| | | | | | | | | | | | | | | | | | These flags are in use for file THP. Link: http://lkml.kernel.org/r/1466021202-61880-23-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * vmscan: split file huge pages before paging them outKirill A. Shutemov2016-07-261-0/+6
| | | | | | | | | | | | | | | | | | | | This is preparation of vmscan for file huge pages. We cannot write out huge pages, so we need to split them on the way out. Link: http://lkml.kernel.org/r/1466021202-61880-22-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp, mlock: do not mlock PTE-mapped file huge pagesKirill A. Shutemov2016-07-265-10/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As with anon THP, we only mlock file huge pages if we can prove that the page is not mapped with PTE. This way we can avoid mlock leak into non-mlocked vma on split. We rely on PageDoubleMap() under lock_page() to check if the the page may be PTE mapped. PG_double_map is set by page_add_file_rmap() when the page mapped with PTEs. Link: http://lkml.kernel.org/r/1466021202-61880-21-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: file pages support for split_huge_page()Kirill A. Shutemov2016-07-262-45/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basic scheme is the same as for anon THP. Main differences: - File pages are on radix-tree, so we have head->_count offset by HPAGE_PMD_NR. The count got distributed to small pages during split. - mapping->tree_lock prevents non-lockless access to pages under split over radix-tree; - Lockless access is prevented by setting the head->_count to 0 during split; - After split, some pages can be beyond i_size. We drop them from radix-tree. - We don't setup migration entries. Just unmap pages. It helps handling cases when i_size is in the middle of the page: no need handle unmap pages beyond i_size manually. Link: http://lkml.kernel.org/r/1466021202-61880-20-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: run vma_adjust_trans_huge() outside i_mmap_rwsemKirill A. Shutemov2016-07-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | vma_addjust_trans_huge() splits pmd if it's crossing VMA boundary. During split we munlock the huge page which requires rmap walk. rmap wants to take the lock on its own. Let's move vma_adjust_trans_huge() outside i_mmap_rwsem to fix this. Link: http://lkml.kernel.org/r/1466021202-61880-19-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: prepare change_huge_pmd() for file thpKirill A. Shutemov2016-07-261-1/+2
| | | | | | | | | | | | | | | | | | | | | | change_huge_pmd() has assert which is not relvant for file page. For shared mapping it's perfectly fine to have page table entry writable, without explicit mkwrite. Link: http://lkml.kernel.org/r/1466021202-61880-18-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: skip file huge pmd on copy_huge_pmd()Kirill A. Shutemov2016-07-261-18/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | copy_page_range() has a check for "Don't copy ptes where a page fault will fill them correctly." It works on VMA level. We still copy all page table entries from private mappings, even if they map page cache. We can simplify copy_huge_pmd() a bit by skipping file PMDs. We don't map file private pages with PMDs, so they only can map page cache. It's safe to skip them as they can be re-faulted later. Link: http://lkml.kernel.org/r/1466021202-61880-17-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: handle file COW faultsKirill A. Shutemov2016-07-261-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | File COW for THP is handled on pte level: just split the pmd. It's not clear how benefitial would be allocation of huge pages on COW faults. And it would require some code to make them work. I think at some point we can consider teaching khugepaged to collapse pages in COW mappings, but allocating huge on fault is probably overkill. Link: http://lkml.kernel.org/r/1466021202-61880-16-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: handle file pages in split_huge_pmd()Kirill A. Shutemov2016-07-261-2/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Splitting THP PMD is simple: just unmap it as in DAX case. This way we can avoid memory overhead on page table allocation to deposit. It's probably a good idea to try to allocation page table with GFP_ATOMIC in __split_huge_pmd_locked() to avoid refaulting the area, but clearing pmd should be good enough for now. Unlike DAX, we also remove the page from rmap and drop reference. pmd_young() is transfered to PageReferenced(). Link: http://lkml.kernel.org/r/1466021202-61880-15-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp: support file pages in zap_huge_pmd()Kirill A. Shutemov2016-07-261-3/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | split_huge_pmd() for file mappings (and DAX too) is implemented by just clearing pmd entry as we can re-fill this area from page cache on pte level later. This means we don't need deposit page tables when file THP is mapped. Therefore we shouldn't try to withdraw a page table on zap_huge_pmd() file THP PMD. Link: http://lkml.kernel.org/r/1466021202-61880-14-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp, vmstats: add counters for huge file pagesKirill A. Shutemov2016-07-263-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | THP_FILE_ALLOC: how many times huge page was allocated and put page cache. THP_FILE_MAPPED: how many times file huge page was mapped. Link: http://lkml.kernel.org/r/1466021202-61880-13-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: introduce do_set_pmd()Kirill A. Shutemov2016-07-264-8/+74
| | | | | | | | | | | | | | | | | | | | | | | | | | | | With postponed page table allocation we have chance to setup huge pages. do_set_pte() calls do_set_pmd() if following criteria met: - page is compound; - pmd entry in pmd_none(); - vma has suitable size and alignment; Link: http://lkml.kernel.org/r/1466021202-61880-12-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * rmap: support file thpKirill A. Shutemov2016-07-266-20/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Naive approach: on mapping/unmapping the page as compound we update ->_mapcount on each 4k page. That's not efficient, but it's not obvious how we can optimize this. We can look into optimization later. PG_double_map optimization doesn't work for file pages since lifecycle of file pages is different comparing to anon pages: file page can be mapped again at any time. Link: http://lkml.kernel.org/r/1466021202-61880-11-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: postpone page table allocation until we have page to mapKirill A. Shutemov2016-07-263-127/+197
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea (and most of code) is borrowed again: from Hugh's patchset on huge tmpfs[1]. Instead of allocation pte page table upfront, we postpone this until we have page to map in hands. This approach opens possibility to map the page as huge if filesystem supports this. Comparing to Hugh's patch I've pushed page table allocation a bit further: into do_set_pte(). This way we can postpone allocation even in faultaround case without moving do_fault_around() after __do_fault(). do_set_pte() got renamed to alloc_set_pte() as it can allocate page table if required. [1] http://lkml.kernel.org/r/alpine.LSU.2.11.1502202015090.14414@eggly.anvils Link: http://lkml.kernel.org/r/1466021202-61880-10-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: introduce fault_envKirill A. Shutemov2016-07-2610-516/+475
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The idea borrowed from Peter's patch from patchset on speculative page faults[1]: Instead of passing around the endless list of function arguments, replace the lot with a single structure so we can change context without endless function signature changes. The changes are mostly mechanical with exception of faultaround code: filemap_map_pages() got reworked a bit. This patch is preparation for the next one. [1] http://lkml.kernel.org/r/20141020222841.302891540@infradead.org Link: http://lkml.kernel.org/r/1466021202-61880-9-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: do not pass mm_struct into handle_mm_faultKirill A. Shutemov2016-07-2636-51/+48
| | | | | | | | | | | | | | | | | | We always have vma->vm_mm around. Link: http://lkml.kernel.org/r/1466021202-61880-8-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * thp, mlock: update unevictable-lru.txtKirill A. Shutemov2016-07-261-0/+21
| | | | | | | | | | | | | | | | | | Add description of THP handling into unevictable-lru.txt. Link: http://lkml.kernel.org/r/1466021202-61880-7-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * khugepaged: recheck pmd after mmap_sem re-acquiredKirill A. Shutemov2016-07-261-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | Vlastimil noted[1] that pmd can be no longer valid after we drop mmap_sem. We need recheck it once mmap_sem taken again. [1] http://lkml.kernel.org/r/12918dcd-a695-c6f4-e06f-69141c5f357f@suse.cz Link: http://lkml.kernel.org/r/1466021202-61880-6-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: fix locking inconsistency in collapse_huge_pageEbru Akagunduz2016-07-261-4/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | After creating revalidate vma function, locking inconsistency occured due to directing the code path to wrong label. This patch directs to correct label and fix the inconsistency. Related commit that caused inconsistency: http://git.kernel.org/cgit/linux/kernel/git/next/linux-next.git/commit/?id=da4360877094368f6dfe75bbe804b0f0a5d575b0 Link: http://lkml.kernel.org/r/1464956884-4644-1-git-send-email-ebru.akagunduz@gmail.com Link: http://lkml.kernel.org/r/1466021202-61880-4-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Rik van Riel <riel@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, thp: make swapin readahead under down_read of mmap_semEbru Akagunduz2016-07-261-29/+62
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently khugepaged makes swapin readahead under down_write. This patch supplies to make swapin readahead under down_read instead of down_write. The patch was tested with a test program that allocates 800MB of memory, writes to it, and then sleeps. The system was forced to swap out all. Afterwards, the test program touches the area by writing, it skips a page in each 20 pages of the area. [akpm@linux-foundation.org: update comment to match new code] [kirill.shutemov@linux.intel.com: passing 'vma' to hugepage_vma_revlidate() is useless] Link: http://lkml.kernel.org/r/20160530095058.GA53044@black.fi.intel.com Link: http://lkml.kernel.org/r/1466021202-61880-3-git-send-email-kirill.shutemov@linux.intel.com Link: http://lkml.kernel.org/r/1464335964-6510-4-git-send-email-ebru.akagunduz@gmail.com Link: http://lkml.kernel.org/r/1466021202-61880-2-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Rik van Riel <riel@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Mel Gorman <mgorman@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Minchan Kim <minchan.kim@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: make swapin readahead to improve thp collapse rateEbru Akagunduz2016-07-264-4/+69
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes swapin readahead to improve thp collapse rate. When khugepaged scanned pages, there can be a few of the pages in swap area. With the patch THP can collapse 4kB pages into a THP when there are up to max_ptes_swap swap ptes in a 2MB range. The patch was tested with a test program that allocates 400B of memory, writes to it, and then sleeps. I force the system to swap out all. Afterwards, the test program touches the area by writing, it skips a page in each 20 pages of the area. Without the patch, system did not swap in readahead. THP rate was %65 of the program of the memory, it did not change over time. With this patch, after 10 minutes of waiting khugepaged had collapsed %99 of the program's memory. [kirill.shutemov@linux.intel.com: trivial cleanup of exit path of the function] [kirill.shutemov@linux.intel.com: __collapse_huge_page_swapin(): drop unused 'pte' parameter] [kirill.shutemov@linux.intel.com: do not hold anon_vma lock during swap in] Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm: make optimistic check for swapin readaheadEbru Akagunduz2016-07-262-8/+51
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new sysfs integer knob /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_swap which makes optimistic check for swapin readahead to increase thp collapse rate. Before getting swapped out pages to memory, checks them and allows up to a certain number. It also prints out using tracepoints amount of unmapped ptes. [vdavydov@parallels.com: fix scan not aborted on SCAN_EXCEED_SWAP_PTE] [sfr@canb.auug.org.au: build fix] Link: http://lkml.kernel.org/r/20160616154503.65806e12@canb.auug.org.au Signed-off-by: Ebru Akagunduz <ebru.akagunduz@gmail.com> Acked-by: Rik van Riel <riel@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: David Rientjes <rientjes@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm/memblock.c:memblock_add_range(): if nr_new is 0 just returnnimisolo2016-07-261-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If nr_new is 0 which means there's no region would be added, so just return to the caller. Signed-off-by: nimisolo <nimisolo@gmail.com> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Wei Yang <weiyang@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, memcg: use consistent gfp flags during readaheadMichal Hocko2016-07-268-16/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Vladimir has noticed that we might declare memcg oom even during readahead because read_pages only uses GFP_KERNEL (with mapping_gfp restriction) while __do_page_cache_readahead uses page_cache_alloc_readahead which adds __GFP_NORETRY to prevent from OOMs. This gfp mask discrepancy is really unfortunate and easily fixable. Drop page_cache_alloc_readahead() which only has one user and outsource the gfp_mask logic into readahead_gfp_mask and propagate this mask from __do_page_cache_readahead down to read_pages. This alone would have only very limited impact as most filesystems are implementing ->readpages and the common implementation mpage_readpages does GFP_KERNEL (with mapping_gfp restriction) again. We can tell it to use readahead_gfp_mask instead as this function is called only during readahead as well. The same applies to read_cache_pages. ext4 has its own ext4_mpage_readpages but the path which has pages != NULL can use the same gfp mask. Btrfs, cifs, f2fs and orangefs are doing a very similar pattern to mpage_readpages so the same can be applied to them as well. [akpm@linux-foundation.org: coding-style fixes] [mhocko@suse.com: restrict gfp mask in mpage_alloc] Link: http://lkml.kernel.org/r/20160610074223.GC32285@dhcp22.suse.cz Link: http://lkml.kernel.org/r/1465301556-26431-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Chris Mason <clm@fb.com> Cc: Steve French <sfrench@samba.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Jan Kara <jack@suse.cz> Cc: Mike Marshall <hubcap@omnibond.com> Cc: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Changman Lee <cm224.lee@samsung.com> Cc: Chao Yu <yuchao0@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * mm, oom_reaper: make sure that mmput_async is called only when memory was reapedMichal Hocko2016-07-261-7/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tetsuo is worried that mmput_async might still lead to a premature new oom victim selection due to the following race: __oom_reap_task exit_mm find_lock_task_mm atomic_inc(mm->mm_users) # = 2 task_unlock task_lock task->mm = NULL up_read(&mm->mmap_sem) < somebody write locks mmap_sem > task_unlock mmput atomic_dec_and_test # = 1 exit_oom_victim down_read_trylock # failed - no reclaim mmput_async # Takes unpredictable amount of time < new OOM situation > the final __mmput will be executed in the delayed context which might happen far in the future. Such a race is highly unlikely because the write holder of mmap_sem would have to be an external task (all direct holders are already killed or exiting) and it usually have to pin mm_users in order to do anything reasonable. We can, however, make sure that the mmput_async is only called when we do not back off and reap some memory. That would reduce the impact of the delayed __mmput because the real content would be already freed. Pin mm_count to keep it alive after we drop task_lock and before we try to get mmap_sem. If the mmap_sem succeeds we can try to grab mm_users reference and then go on with unmapping the address space. It is not clear whether this race is possible at all but it is better to be more robust and do not pin mm_users unless we are sure we are actually doing some real work during __oom_reap_task. Link: http://lkml.kernel.org/r/1465306987-30297-1-git-send-email-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| * include/linux/memblock.h: Clean up code for several trivial detailsChen Gang2016-07-261-11/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct the function parameters alignment, since original code already use both tabs and white spaces together for the incorrect parameters alignment functions. If one line can hold one statement within 80 columns, let it in one line (original code did not consider about the tabs/spaces for 2nd line when a statement is separated into 2 lines). Try to let '' aligned within one macro, since all related lines are short enough. Remove useless statement "idx = 0;", and always assign rgn within the 'for' statement. Link: http://lkml.kernel.org/r/1464904899-1714-1-git-send-email-chengang@emindsoft.com.cn Signed-off-by: Chen Gang <gang.chen.5i5j@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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