1. 17 3月, 2020 1 次提交
    • Y
      pagecache: support percpu refcount to imporve performance · 8b9ea901
      Yunfeng Ye 提交于
      euleros inclusion
      category: feature
      feature: pagecache percpu refcount
      bugzilla: 31398
      CVE: NA
      
      -------------------------------------------------
      
      The pagecache manages the file physical pages, and the life cycle of
      page is managed by atomic counting. With the increasing number of cpu
      cores, the cost of atomic counting is very large when reading file
      pagecaches at large concurrent.
      
      For example, when running nginx http application, the biggest hotspot is
      found in the atomic operation of find_get_entry():
      
       11.94% [kernel] [k] find_get_entry
        7.45% [kernel] [k] do_tcp_sendpages
        6.12% [kernel] [k] generic_file_buffered_read
      
      So we using the percpu refcount mechanism to fix this problem. and the
      test result show that the read performance of nginx http can be improved
      by 100%:
      
        worker   original(requests/sec)   percpu(requests/sec)   imporve
        64       759656.87                1627088.95             114.2%
      
      Notes: we use page->lru to save percpu information, so the pages with
      percpu attribute will not be recycled by memory recycling process, we
      should avoid grow the file size unlimited.
      Signed-off-by: NYunfeng Ye <yeyunfeng@huawei.com>
      Reviewed-by: NKefeng Wang <wangkefeng.wang@huawei.com>
      Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
      8b9ea901
  2. 27 12月, 2019 2 次提交
  3. 12 4月, 2018 1 次提交
  4. 16 11月, 2017 4 次提交
  5. 02 11月, 2017 1 次提交
    • G
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman 提交于
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: NKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: NPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: NThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  6. 07 9月, 2017 2 次提交
  7. 03 8月, 2017 1 次提交
    • K
      mm: allow page_cache_get_speculative in interrupt context · 1ee1c3f5
      Kan Liang 提交于
      Kernel panic when calling the IRQ-safe __get_user_pages_fast in NMI
      handler.
      
      The bug was introduced by commit 2947ba05 ("x86/mm/gup: Switch GUP
      to the generic get_user_page_fast() implementation").
      
      The original x86 __get_user_page_fast used plain get_page() or
      page_ref_add().  However, the generic __get_user_page_fast uses
      page_cache_get_speculative(), which has VM_BUG_ON(in_interrupt()).
      
      There is no reason to prevent page_cache_get_speculative from using in
      interrupt context.  According to the author, putting a BUG_ON there is
      just because the code is not verifying correctness of interrupt races.
      I did some tests in interrupt context.  There is no issue found.
      
      Removing VM_BUG_ON(in_interrupt()) for page_cache_get_speculative().
      
      Link: http://lkml.kernel.org/r/1501609146-59730-1-git-send-email-kan.liang@intel.com
      Fixes: 2947ba05 ("x86/mm/gup: Switch GUP to the generic get_user_page_fast() implementation")
      Signed-off-by: NKan Liang <kan.liang@intel.com>
      Cc: Jens Axboe <axboe@fb.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Cc: Ying Huang <ying.huang@intel.com>
      Cc: Nicholas Piggin <npiggin@gmail.com>
      Cc: Ingo Molnar <mingo@kernel.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1ee1c3f5
  8. 06 7月, 2017 1 次提交
    • J
      mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error · 8ed1e46a
      Jeff Layton 提交于
      When a writeback error occurs, we want later callers to be able to pick
      up that fact when they go to wait on that writeback to complete.
      Traditionally, we've used AS_EIO/AS_ENOSPC flags to track that, but
      that's problematic since only one "checker" will be informed when an
      error occurs.
      
      In later patches, we're going to want to convert many of these callers
      to check for errors since a well-defined point in time. For now, ensure
      that we can handle both sorts of checks by both setting errors in both
      places when there is a writeback failure.
      Signed-off-by: NJeff Layton <jlayton@redhat.com>
      8ed1e46a
  9. 20 6月, 2017 1 次提交
    • I
      sched/wait: Rename wait_queue_t => wait_queue_entry_t · ac6424b9
      Ingo Molnar 提交于
      Rename:
      
      	wait_queue_t		=>	wait_queue_entry_t
      
      'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
      but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
      which had to carry the name.
      
      Start sorting this out by renaming it to 'wait_queue_entry_t'.
      
      This also allows the real structure name 'struct __wait_queue' to
      lose its double underscore and become 'struct wait_queue_entry',
      which is the more canonical nomenclature for such data types.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: NIngo Molnar <mingo@kernel.org>
      ac6424b9
  10. 28 3月, 2017 1 次提交
  11. 23 2月, 2017 2 次提交
  12. 26 12月, 2016 1 次提交
    • N
      mm: add PageWaiters indicating tasks are waiting for a page bit · 62906027
      Nicholas Piggin 提交于
      Add a new page flag, PageWaiters, to indicate the page waitqueue has
      tasks waiting. This can be tested rather than testing waitqueue_active
      which requires another cacheline load.
      
      This bit is always set when the page has tasks on page_waitqueue(page),
      and is set and cleared under the waitqueue lock. It may be set when
      there are no tasks on the waitqueue, which will cause a harmless extra
      wakeup check that will clears the bit.
      
      The generic bit-waitqueue infrastructure is no longer used for pages.
      Instead, waitqueues are used directly with a custom key type. The
      generic code was not flexible enough to have PageWaiters manipulation
      under the waitqueue lock (which simplifies concurrency).
      
      This improves the performance of page lock intensive microbenchmarks by
      2-3%.
      
      Putting two bits in the same word opens the opportunity to remove the
      memory barrier between clearing the lock bit and testing the waiters
      bit, after some work on the arch primitives (e.g., ensuring memory
      operand widths match and cover both bits).
      Signed-off-by: NNicholas Piggin <npiggin@gmail.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Bob Peterson <rpeterso@redhat.com>
      Cc: Steven Whitehouse <swhiteho@redhat.com>
      Cc: Andrew Lutomirski <luto@kernel.org>
      Cc: Andreas Gruenbacher <agruenba@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      62906027
  13. 25 12月, 2016 1 次提交
  14. 01 12月, 2016 1 次提交
  15. 12 10月, 2016 1 次提交
    • M
      mm: split gfp_mask and mapping flags into separate fields · 9c5d760b
      Michal Hocko 提交于
      mapping->flags currently encodes two different things into a single flag.
      It contains sticky gfp_mask for page cache allocations and AS_ codes used
      to report errors/enospace and other states which are mapping specific.
      Condensing the two semantically unrelated things saves few bytes but it
      also complicates other things.  For one thing the gfp flags space is
      reduced and in fact we are already running out of available bits.  It can
      be assumed that more gfp flags will be necessary later on.
      
      To not introduce the address_space grow (at least on x86_64) we can stick
      it right after private_lock because we have a hole there.
      
      struct address_space {
              struct inode *             host;                 /*     0     8 */
              struct radix_tree_root     page_tree;            /*     8    16 */
              spinlock_t                 tree_lock;            /*    24     4 */
              atomic_t                   i_mmap_writable;      /*    28     4 */
              struct rb_root             i_mmap;               /*    32     8 */
              struct rw_semaphore        i_mmap_rwsem;         /*    40    40 */
              /* --- cacheline 1 boundary (64 bytes) was 16 bytes ago --- */
              long unsigned int          nrpages;              /*    80     8 */
              long unsigned int          nrexceptional;        /*    88     8 */
              long unsigned int          writeback_index;      /*    96     8 */
              const struct address_space_operations  * a_ops;  /*   104     8 */
              long unsigned int          flags;                /*   112     8 */
              spinlock_t                 private_lock;         /*   120     4 */
      
              /* XXX 4 bytes hole, try to pack */
      
              /* --- cacheline 2 boundary (128 bytes) --- */
              struct list_head           private_list;         /*   128    16 */
              void *                     private_data;         /*   144     8 */
      
              /* size: 152, cachelines: 3, members: 14 */
              /* sum members: 148, holes: 1, sum holes: 4 */
              /* last cacheline: 24 bytes */
      };
      
      Link: http://lkml.kernel.org/r/20160912114852.GI14524@dhcp22.suse.czSigned-off-by: NMichal Hocko <mhocko@suse.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      9c5d760b
  16. 08 10月, 2016 2 次提交
    • H
      mm: remove page_file_index · 8cd79788
      Huang Ying 提交于
      After using the offset of the swap entry as the key of the swap cache,
      the page_index() becomes exactly same as page_file_index().  So the
      page_file_index() is removed and the callers are changed to use
      page_index() instead.
      
      Link: http://lkml.kernel.org/r/1473270649-27229-2-git-send-email-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
      Cc: Trond Myklebust <trond.myklebust@primarydata.com>
      Cc: Anna Schumaker <anna.schumaker@netapp.com>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Michal Hocko <mhocko@suse.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
      Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
      Cc: Eric Dumazet <edumazet@google.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8cd79788
    • H
      mm: don't use radix tree writeback tags for pages in swap cache · 371a096e
      Huang Ying 提交于
      File pages use a set of radix tree tags (DIRTY, TOWRITE, WRITEBACK,
      etc.) to accelerate finding the pages with a specific tag in the radix
      tree during inode writeback.  But for anonymous pages in the swap cache,
      there is no inode writeback.  So there is no need to find the pages with
      some writeback tags in the radix tree.  It is not necessary to touch
      radix tree writeback tags for pages in the swap cache.
      
      Per Rik van Riel's suggestion, a new flag AS_NO_WRITEBACK_TAGS is
      introduced for address spaces which don't need to update the writeback
      tags.  The flag is set for swap caches.  It may be used for DAX file
      systems, etc.
      
      With this patch, the swap out bandwidth improved 22.3% (from ~1.2GB/s to
      ~1.48GBps) in the vm-scalability swap-w-seq test case with 8 processes.
      The test is done on a Xeon E5 v3 system.  The swap device used is a RAM
      simulated PMEM (persistent memory) device.  The improvement comes from
      the reduced contention on the swap cache radix tree lock.  To test
      sequential swapping out, the test case uses 8 processes, which
      sequentially allocate and write to the anonymous pages until RAM and
      part of the swap device is used up.
      
      Details of comparison is as follow,
      
      base             base+patch
      ---------------- --------------------------
               %stddev     %change         %stddev
                   \          |                \
         2506952 ±  2%     +28.1%    3212076 ±  7%  vm-scalability.throughput
         1207402 ±  7%     +22.3%    1476578 ±  6%  vmstat.swap.so
           10.86 ± 12%     -23.4%       8.31 ± 16%  perf-profile.cycles-pp._raw_spin_lock_irq.__add_to_swap_cache.add_to_swap_cache.add_to_swap.shrink_page_list
           10.82 ± 13%     -33.1%       7.24 ± 14%  perf-profile.cycles-pp._raw_spin_lock_irqsave.__remove_mapping.shrink_page_list.shrink_inactive_list.shrink_zone_memcg
           10.36 ± 11%    -100.0%       0.00 ± -1%  perf-profile.cycles-pp._raw_spin_lock_irqsave.__test_set_page_writeback.bdev_write_page.__swap_writepage.swap_writepage
           10.52 ± 12%    -100.0%       0.00 ± -1%  perf-profile.cycles-pp._raw_spin_lock_irqsave.test_clear_page_writeback.end_page_writeback.page_endio.pmem_rw_page
      
      Link: http://lkml.kernel.org/r/1472578089-5560-1-git-send-email-ying.huang@intel.comSigned-off-by: N"Huang, Ying" <ying.huang@intel.com>
      Acked-by: NRik van Riel <riel@redhat.com>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Shaohua Li <shli@kernel.org>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: Tejun Heo <tj@kernel.org>
      Cc: Wu Fengguang <fengguang.wu@intel.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      371a096e
  17. 28 9月, 2016 1 次提交
    • A
      get rid of separate multipage fault-in primitives · 4bce9f6e
      Al Viro 提交于
      * the only remaining callers of "short" fault-ins are just as happy with generic
      variants (both in lib/iov_iter.c); switch them to multipage variants, kill the
      "short" ones
      * rename the multipage variants to now available plain ones.
      * get rid of compat macro defining iov_iter_fault_in_multipage_readable by
      expanding it in its only user.
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      4bce9f6e
  18. 26 9月, 2016 1 次提交
  19. 21 9月, 2016 1 次提交
    • A
      fix fault_in_multipages_...() on architectures with no-op access_ok() · e23d4159
      Al Viro 提交于
      Switching iov_iter fault-in to multipages variants has exposed an old
      bug in underlying fault_in_multipages_...(); they break if the range
      passed to them wraps around.  Normally access_ok() done by callers will
      prevent such (and it's a guaranteed EFAULT - ERR_PTR() values fall into
      such a range and they should not point to any valid objects).
      
      However, on architectures where userland and kernel live in different
      MMU contexts (e.g. s390) access_ok() is a no-op and on those a range
      with a wraparound can reach fault_in_multipages_...().
      
      Since any wraparound means EFAULT there, the fix is trivial - turn
      those
      
          while (uaddr <= end)
      	    ...
      into
      
          if (unlikely(uaddr > end))
      	    return -EFAULT;
          do
      	    ...
          while (uaddr <= end);
      Reported-by: NJan Stancek <jstancek@redhat.com>
      Tested-by: NJan Stancek <jstancek@redhat.com>
      Cc: stable@vger.kernel.org # v3.5+
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e23d4159
  20. 08 8月, 2016 1 次提交
  21. 05 8月, 2016 1 次提交
  22. 27 7月, 2016 1 次提交
    • M
      mm, memcg: use consistent gfp flags during readahead · 8a5c743e
      Michal Hocko 提交于
      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.orgSigned-off-by: NMichal 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      8a5c743e
  23. 21 5月, 2016 1 次提交
  24. 20 5月, 2016 1 次提交
    • J
      mm: rename _count, field of the struct page, to _refcount · 0139aa7b
      Joonsoo Kim 提交于
      Many developers already know that field for reference count of the
      struct page is _count and atomic type.  They would try to handle it
      directly and this could break the purpose of page reference count
      tracepoint.  To prevent direct _count modification, this patch rename it
      to _refcount and add warning message on the code.  After that, developer
      who need to handle reference count will find that field should not be
      accessed directly.
      
      [akpm@linux-foundation.org: fix comments, per Vlastimil]
      [akpm@linux-foundation.org: Documentation/vm/transhuge.txt too]
      [sfr@canb.auug.org.au: sync ethernet driver changes]
      Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Johannes Berg <johannes@sipsolutions.net>
      Cc: "David S. Miller" <davem@davemloft.net>
      Cc: Sunil Goutham <sgoutham@cavium.com>
      Cc: Chris Metcalf <cmetcalf@mellanox.com>
      Cc: Manish Chopra <manish.chopra@qlogic.com>
      Cc: Yuval Mintz <yuval.mintz@qlogic.com>
      Cc: Tariq Toukan <tariqt@mellanox.com>
      Cc: Saeed Mahameed <saeedm@mellanox.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      0139aa7b
  25. 05 4月, 2016 3 次提交
  26. 18 3月, 2016 1 次提交
    • J
      mm: introduce page reference manipulation functions · fe896d18
      Joonsoo Kim 提交于
      The success of CMA allocation largely depends on the success of
      migration and key factor of it is page reference count.  Until now, page
      reference is manipulated by direct calling atomic functions so we cannot
      follow up who and where manipulate it.  Then, it is hard to find actual
      reason of CMA allocation failure.  CMA allocation should be guaranteed
      to succeed so finding offending place is really important.
      
      In this patch, call sites where page reference is manipulated are
      converted to introduced wrapper function.  This is preparation step to
      add tracepoint to each page reference manipulation function.  With this
      facility, we can easily find reason of CMA allocation failure.  There is
      no functional change in this patch.
      
      In addition, this patch also converts reference read sites.  It will
      help a second step that renames page._count to something else and
      prevents later attempt to direct access to it (Suggested by Andrew).
      Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
      Acked-by: NMichal Nazarewicz <mina86@mina86.com>
      Acked-by: NVlastimil Babka <vbabka@suse.cz>
      Cc: Minchan Kim <minchan@kernel.org>
      Cc: Mel Gorman <mgorman@techsingularity.net>
      Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
      Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
      Cc: Steven Rostedt <rostedt@goodmis.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      fe896d18
  27. 16 3月, 2016 1 次提交
  28. 23 1月, 2016 1 次提交
    • R
      mm: add find_get_entries_tag() · 7e7f7749
      Ross Zwisler 提交于
      Add find_get_entries_tag() to the family of functions that include
      find_get_entries(), find_get_pages() and find_get_pages_tag().  This is
      needed for DAX dirty page handling because we need a list of both page
      offsets and radix tree entries ('indices' and 'entries' in this
      function) that are marked with the PAGECACHE_TAG_TOWRITE tag.
      Signed-off-by: NRoss Zwisler <ross.zwisler@linux.intel.com>
      Reviewed-by: NJan Kara <jack@suse.cz>
      Cc: "H. Peter Anvin" <hpa@zytor.com>
      Cc: "J. Bruce Fields" <bfields@fieldses.org>
      Cc: "Theodore Ts'o" <tytso@mit.edu>
      Cc: Alexander Viro <viro@zeniv.linux.org.uk>
      Cc: Andreas Dilger <adilger.kernel@dilger.ca>
      Cc: Dave Chinner <david@fromorbit.com>
      Cc: Ingo Molnar <mingo@redhat.com>
      Cc: Jeff Layton <jlayton@poochiereds.net>
      Cc: Matthew Wilcox <willy@linux.intel.com>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: Dan Williams <dan.j.williams@intel.com>
      Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
      Cc: Dave Hansen <dave.hansen@linux.intel.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      7e7f7749
  29. 16 1月, 2016 2 次提交
    • K
      thp: reintroduce split_huge_page() · e9b61f19
      Kirill A. Shutemov 提交于
      This patch adds implementation of split_huge_page() for new
      refcountings.
      
      Unlike previous implementation, new split_huge_page() can fail if
      somebody holds GUP pin on the page.  It also means that pin on page
      would prevent it from bening split under you.  It makes situation in
      many places much cleaner.
      
      The basic scheme of split_huge_page():
      
        - Check that sum of mapcounts of all subpage is equal to page_count()
          plus one (caller pin). Foll off with -EBUSY. This way we can avoid
          useless PMD-splits.
      
        - Freeze the page counters by splitting all PMD and setup migration
          PTEs.
      
        - Re-check sum of mapcounts against page_count(). Page's counts are
          stable now. -EBUSY if page is pinned.
      
        - Split compound page.
      
        - Unfreeze the page by removing migration entries.
      Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
      Tested-by: NSasha Levin <sasha.levin@oracle.com>
      Tested-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
      Acked-by: NJerome 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      e9b61f19
    • K
      page-flags: define PG_locked behavior on compound pages · 48c935ad
      Kirill A. Shutemov 提交于
      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: NKirill 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: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      48c935ad
  30. 07 11月, 2015 1 次提交