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  1. 21 Mar, 2012 2 commits
  3. 07 Jan, 2012 1 commit
  5. 04 Jan, 2012 5 commits
  7. 02 Nov, 2011 1 commit
  9. 28 May, 2011 1 commit
  11. 26 May, 2011 2 commits
  13. 10 Mar, 2011 1 commit
  15. 03 Mar, 2011 1 commit
  17. 13 Jan, 2011 1 commit
  19. 07 Jan, 2011 3 commits
    • Nick Piggin's avatar
      fs: dcache reduce branches in lookup path · fb045adb
      Nick Piggin authored 
      
Reduce some branches and memory accesses in dcache lookup by adding dentry
flags to indicate common d_ops are set, rather than having to check them.
This saves a pointer memory access (dentry->d_op) in common path lookup
situations, and saves another pointer load and branch in cases where we
have d_op but not the particular operation.

Patched with:

git grep -E '[.>]([[:space:]])*d_op([[:space:]])*=' | xargs sed -e 's/\([^\t ]*\)->d_op = \(.*\);/d_set_d_op(\1, \2);/' -e 's/\([^\t ]*\)\.d_op = \(.*\);/d_set_d_op(\&\1, \2);/' -i
Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      fb045adb
    • Nick Piggin's avatar
      fs: icache RCU free inodes · fa0d7e3d
      Nick Piggin authored 
      
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.
Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      fa0d7e3d
    • Nick Piggin's avatar
      fs: change d_hash for rcu-walk · b1e6a015
      Nick Piggin authored 
      
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.

For in-tree filesystems, this is just a mechanical change.
Signed-off-by: default avatarNick Piggin <npiggin@kernel.dk>
      b1e6a015
  21. 29 Oct, 2010 1 commit
  23. 26 Oct, 2010 1 commit
  25. 11 Aug, 2010 6 commits
  27. 09 Aug, 2010 8 commits
  29. 29 Jun, 2010 1 commit
  31. 28 May, 2010 2 commits
    • Al Viro's avatar
      fix fs/sysv s_dirt handling · 4c9002de
      Al Viro authored 
      
got broken on ->sync_fs() conversion a year ago, nobody noticed...
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      4c9002de
    • Christoph Hellwig's avatar
      rename the generic fsync implementations · 1b061d92
      Christoph Hellwig authored 
      
We don't name our generic fsync implementations very well currently.
The no-op implementation for in-memory filesystems currently is called
simple_sync_file which doesn't make too much sense to start with,
the the generic one for simple filesystems is called simple_fsync
which can lead to some confusion.

This patch renames the generic file fsync method to generic_file_fsync
to match the other generic_file_* routines it is supposed to be used
with, and the no-op implementation to noop_fsync to make it obvious
what to expect.  In addition add some documentation for both methods.
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
      1b061d92
  33. 21 May, 2010 1 commit
  35. 15 May, 2010 1 commit
  37. 05 Mar, 2010 1 commit