linux-toradex.git/fs/buffer.c, branch v2.6.38.5

fs: Use this_cpu_inc_return in buffer.c

2010-12-17T14:18:05+00:00

__this_cpu_inc can create a single instruction with the same effect
as the _get_cpu_var(..)++ construct in buffer.c.

Cc: Wu Fengguang 
Cc: Christoph Hellwig 
Acked-by: H. Peter Anvin 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

fs: Use this_cpu_xx operations in buffer.c

2010-12-17T14:07:19+00:00

Optimize various per cpu area operations through these new percpu
operations.  These operations avoid address calculations through the
use of segment prefixes and multiple memory references through RMW
instructions etc.

Reduces code size:

Before:

christoph@linux-2.6$ size fs/buffer.o
   text	   data	    bss	    dec	    hex	filename
  19169	     80	     28	  19277	   4b4d	fs/buffer.o

After:

christoph@linux-2.6$ size fs/buffer.o
   text	   data	    bss	    dec	    hex	filename
  19138	     80	     28	  19246	   4b2e	fs/buffer.o

V3->V4:
	- Move the use of this_cpu_inc_return into a later patch so that
	  this one can go in without percpu infrastructure changes.

Cc: Wu Fengguang 
Cc: Christoph Hellwig 
Acked-by: H. Peter Anvin 
Signed-off-by: Christoph Lameter 
Signed-off-by: Tejun Heo

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6

2010-10-27T00:58:44+00:00

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
  split invalidate_inodes()
  fs: skip I_FREEING inodes in writeback_sb_inodes
  fs: fold invalidate_list into invalidate_inodes
  fs: do not drop inode_lock in dispose_list
  fs: inode split IO and LRU lists
  fs: switch bdev inode bdi's correctly
  fs: fix buffer invalidation in invalidate_list
  fsnotify: use dget_parent
  smbfs: use dget_parent
  exportfs: use dget_parent
  fs: use RCU read side protection in d_validate
  fs: clean up dentry lru modification
  fs: split __shrink_dcache_sb
  fs: improve DCACHE_REFERENCED usage
  fs: use percpu counter for nr_dentry and nr_dentry_unused
  fs: simplify __d_free
  fs: take dcache_lock inside __d_path
  fs: do not assign default i_ino in new_inode
  fs: introduce a per-cpu last_ino allocator
  new helper: ihold()
  ...

fs/buffer.c: remove duplicated assignment to b_private

2010-10-26T23:52:13+00:00

bh->b_private is initialized within init_buffer(), thus this assignment is
redundant.

Signed-off-by: Namhyung Kim 
Cc: Al Viro 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

writeback: remove nonblocking/encountered_congestion references

2010-10-26T23:52:05+00:00

This removes more dead code that was somehow missed by commit 0d99519efef
(writeback: remove unused nonblocking and congestion checks).  There are
no behavior change except for the removal of two entries from one of the
ext4 tracing interface.

The nonblocking checks in ->writepages are no longer used because the
flusher now prefer to block on get_request_wait() than to skip inodes on
IO congestion.  The latter will lead to more seeky IO.

The nonblocking checks in ->writepage are no longer used because it's
redundant with the WB_SYNC_NONE check.

We no long set ->nonblocking in VM page out and page migration, because
a) it's effectively redundant with WB_SYNC_NONE in current code
b) it's old semantic of "Don't get stuck on request queues" is mis-behavior:
   that would skip some dirty inodes on congestion and page out others, which
   is unfair in terms of LRU age.

Inspired by Christoph Hellwig. Thanks!

Signed-off-by: Wu Fengguang 
Cc: Theodore Ts'o 
Cc: David Howells 
Cc: Sage Weil 
Cc: Steve French 
Cc: Chris Mason 
Cc: Jens Axboe 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

fs/buffer.c: call __block_write_begin() if we have page

2010-10-26T01:18:23+00:00

If we have the appropriate page already, call __block_write_begin()
directly instead of releasing and regrabbing it inside of
block_write_begin().

Signed-off-by: Namhyung Kim 
Signed-off-by: Al Viro

fs/buffer.c: remove duplicated assignment on b_private

2010-10-26T01:18:22+00:00

bh->b_private is initialized within init_buffer(), thus the
assignment should be redundant. Remove it.

Signed-off-by: Namhyung Kim 
Signed-off-by: Al Viro

fs: kill block_prepare_write

2010-10-26T01:18:20+00:00

__block_write_begin and block_prepare_write are identical except for slightly
different calling conventions.  Convert all callers to the __block_write_begin
calling conventions and drop block_prepare_write.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro

block: remove the BH_Eopnotsupp flag

2010-09-10T10:35:40+00:00

This flag was only set for barrier buffers, which we don't submit
anymore.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Tejun Heo 
Signed-off-by: Jens Axboe

remove SWRITE* I/O types

2010-08-18T05:09:01+00:00

These flags aren't real I/O types, but tell ll_rw_block to always
lock the buffer instead of giving up on a failed trylock.

Instead add a new write_dirty_buffer helper that implements this semantic
and use it from the existing SWRITE* callers.  Note that the ll_rw_block
code had a bug where it didn't promote WRITE_SYNC_PLUG properly, which
this patch fixes.

In the ufs code clean up the helper that used to call ll_rw_block
to mirror sync_dirty_buffer, which is the function it implements for
compound buffers.

Signed-off-by: Christoph Hellwig 
Signed-off-by: Al Viro