1. 12 4月, 2015 7 次提交
  2. 26 3月, 2015 1 次提交
  3. 14 3月, 2015 2 次提交
    • C
      fs: split generic and aio kiocb · 04b2fa9f
      Christoph Hellwig 提交于
      Most callers in the kernel want to perform synchronous file I/O, but
      still have to bloat the stack with a full struct kiocb.  Split out
      the parts needed in filesystem code from those in the aio code, and
      only allocate those needed to pass down argument on the stack.  The
      aio code embedds the generic iocb in the one it allocates and can
      easily get back to it by using container_of.
      
      Also add a ->ki_complete method to struct kiocb, this is used to call
      into the aio code and thus removes the dependency on aio for filesystems
      impementing asynchronous operations.  It will also allow other callers
      to substitute their own completion callback.
      
      We also add a new ->ki_flags field to work around the nasty layering
      violation recently introduced in commit 5e33f6 ("usb: gadget: ffs: add
      eventfd notification about ffs events").
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      04b2fa9f
    • C
      fuse: handle synchronous iocbs internally · 9d5722b7
      Christoph Hellwig 提交于
      Based on a patch from Maxim Patlasov <MPatlasov@parallels.com>.
      Signed-off-by: NChristoph Hellwig <hch@lst.de>
      Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
      9d5722b7
  4. 11 2月, 2015 1 次提交
  5. 21 1月, 2015 1 次提交
  6. 12 12月, 2014 3 次提交
  7. 20 11月, 2014 1 次提交
  8. 27 9月, 2014 1 次提交
  9. 08 8月, 2014 1 次提交
  10. 14 7月, 2014 2 次提交
  11. 05 6月, 2014 1 次提交
    • M
      mm: non-atomically mark page accessed during page cache allocation where possible · 2457aec6
      Mel Gorman 提交于
      aops->write_begin may allocate a new page and make it visible only to have
      mark_page_accessed called almost immediately after.  Once the page is
      visible the atomic operations are necessary which is noticable overhead
      when writing to an in-memory filesystem like tmpfs but should also be
      noticable with fast storage.  The objective of the patch is to initialse
      the accessed information with non-atomic operations before the page is
      visible.
      
      The bulk of filesystems directly or indirectly use
      grab_cache_page_write_begin or find_or_create_page for the initial
      allocation of a page cache page.  This patch adds an init_page_accessed()
      helper which behaves like the first call to mark_page_accessed() but may
      called before the page is visible and can be done non-atomically.
      
      The primary APIs of concern in this care are the following and are used
      by most filesystems.
      
      	find_get_page
      	find_lock_page
      	find_or_create_page
      	grab_cache_page_nowait
      	grab_cache_page_write_begin
      
      All of them are very similar in detail to the patch creates a core helper
      pagecache_get_page() which takes a flags parameter that affects its
      behavior such as whether the page should be marked accessed or not.  Then
      old API is preserved but is basically a thin wrapper around this core
      function.
      
      Each of the filesystems are then updated to avoid calling
      mark_page_accessed when it is known that the VM interfaces have already
      done the job.  There is a slight snag in that the timing of the
      mark_page_accessed() has now changed so in rare cases it's possible a page
      gets to the end of the LRU as PageReferenced where as previously it might
      have been repromoted.  This is expected to be rare but it's worth the
      filesystem people thinking about it in case they see a problem with the
      timing change.  It is also the case that some filesystems may be marking
      pages accessed that previously did not but it makes sense that filesystems
      have consistent behaviour in this regard.
      
      The test case used to evaulate this is a simple dd of a large file done
      multiple times with the file deleted on each iterations.  The size of the
      file is 1/10th physical memory to avoid dirty page balancing.  In the
      async case it will be possible that the workload completes without even
      hitting the disk and will have variable results but highlight the impact
      of mark_page_accessed for async IO.  The sync results are expected to be
      more stable.  The exception is tmpfs where the normal case is for the "IO"
      to not hit the disk.
      
      The test machine was single socket and UMA to avoid any scheduling or NUMA
      artifacts.  Throughput and wall times are presented for sync IO, only wall
      times are shown for async as the granularity reported by dd and the
      variability is unsuitable for comparison.  As async results were variable
      do to writback timings, I'm only reporting the maximum figures.  The sync
      results were stable enough to make the mean and stddev uninteresting.
      
      The performance results are reported based on a run with no profiling.
      Profile data is based on a separate run with oprofile running.
      
      async dd
                                          3.15.0-rc3            3.15.0-rc3
                                             vanilla           accessed-v2
      ext3    Max      elapsed     13.9900 (  0.00%)     11.5900 ( 17.16%)
      tmpfs	Max      elapsed      0.5100 (  0.00%)      0.4900 (  3.92%)
      btrfs   Max      elapsed     12.8100 (  0.00%)     12.7800 (  0.23%)
      ext4	Max      elapsed     18.6000 (  0.00%)     13.3400 ( 28.28%)
      xfs	Max      elapsed     12.5600 (  0.00%)      2.0900 ( 83.36%)
      
      The XFS figure is a bit strange as it managed to avoid a worst case by
      sheer luck but the average figures looked reasonable.
      
              samples percentage
      ext3       86107    0.9783  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
      ext3       23833    0.2710  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
      ext3        5036    0.0573  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
      ext4       64566    0.8961  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
      ext4        5322    0.0713  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
      ext4        2869    0.0384  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
      xfs        62126    1.7675  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
      xfs         1904    0.0554  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
      xfs          103    0.0030  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
      btrfs      10655    0.1338  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
      btrfs       2020    0.0273  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
      btrfs        587    0.0079  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
      tmpfs      59562    3.2628  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
      tmpfs       1210    0.0696  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
      tmpfs         94    0.0054  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
      
      [akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
      Signed-off-by: NMel Gorman <mgorman@suse.de>
      Cc: Johannes Weiner <hannes@cmpxchg.org>
      Cc: Vlastimil Babka <vbabka@suse.cz>
      Cc: Jan Kara <jack@suse.cz>
      Cc: Michal Hocko <mhocko@suse.cz>
      Cc: Hugh Dickins <hughd@google.com>
      Cc: Dave Hansen <dave.hansen@intel.com>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
      Cc: Oleg Nesterov <oleg@redhat.com>
      Cc: Rik van Riel <riel@redhat.com>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Tested-by: NPrabhakar Lad <prabhakar.csengg@gmail.com>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      2457aec6
  12. 02 6月, 2014 1 次提交
    • J
      locks: ensure that fl_owner is always initialized properly in flock and lease codepaths · 130d1f95
      Jeff Layton 提交于
      Currently, the fl_owner isn't set for flock locks. Some filesystems use
      byte-range locks to simulate flock locks and there is a common idiom in
      those that does:
      
          fl->fl_owner = (fl_owner_t)filp;
          fl->fl_start = 0;
          fl->fl_end = OFFSET_MAX;
      
      Since flock locks are generally "owned" by the open file description,
      move this into the common flock lock setup code. The fl_start and fl_end
      fields are already set appropriately, so remove the unneeded setting of
      that in flock ops in those filesystems as well.
      
      Finally, the lease code also sets the fl_owner as if they were owned by
      the process and not the open file description. This is incorrect as
      leases have the same ownership semantics as flock locks. Set them the
      same way. The lease code doesn't actually use the fl_owner value for
      anything, so this is more for consistency's sake than a bugfix.
      Reported-by: NTrond Myklebust <trond.myklebust@primarydata.com>
      Signed-off-by: NJeff Layton <jlayton@poochiereds.net>
      Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> (Staging portion)
      Acked-by: NJ. Bruce Fields <bfields@fieldses.org>
      130d1f95
  13. 07 5月, 2014 13 次提交
  14. 28 4月, 2014 5 次提交