linux/fs/gfs2
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
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: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
..
acl.c Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-fixes 2010-05-25 08:17:51 -07:00
acl.h gfs: constify xattr_handler 2010-05-21 18:31:20 -04:00
aops.c fs: kill block_prepare_write 2010-10-25 21:18:20 -04:00
bmap.c GFS2: reserve more blocks for transactions 2010-09-28 09:44:24 +01:00
bmap.h GFS2: New truncate sequence 2010-09-20 11:18:16 +01:00
dentry.c fs: change d_hash for rcu-walk 2011-01-07 17:50:20 +11:00
dir.c GFS2: Make . and .. qstrs constant 2010-09-20 11:21:09 +01:00
dir.h GFS2: Make . and .. qstrs constant 2010-09-20 11:21:09 +01:00
export.c GFS2: Fix inode deallocation race 2010-11-15 12:44:42 +00:00
file.c locks: let the caller free file_lock on ->setlease failure 2010-10-31 06:35:15 -07:00
gfs2.h [GFS2] Remove remote lock dropping code 2008-06-27 09:39:44 +01:00
glock.c GFS2: Fix inode deallocation race 2010-11-15 12:44:42 +00:00
glock.h GFS2: fixed typo 2010-10-18 14:38:07 +01:00
glops.c GFS2: Fix type mapping for demote_rq interface 2010-10-06 09:58:44 +01:00
glops.h GFS2: Add a "demote a glock" interface to sysfs 2009-03-24 11:21:22 +00:00
incore.h GFS2: Improve journal allocation via sysfs 2010-09-29 15:04:18 +01:00
inode.c GFS2: Fix inode deallocation race 2010-11-15 12:44:42 +00:00
inode.h GFS2: Fix inode deallocation race 2010-11-15 12:44:42 +00:00
Kconfig GFS2: No longer experimental 2010-09-20 11:18:46 +01:00
lock_dlm.c GFS2: Update handling of DLM return codes to match reality 2010-09-20 11:20:12 +01:00
log.c Merge branch 'v2.6.36-rc8' into for-2.6.37/barrier 2010-10-19 09:13:04 +02:00
log.h GFS2: Rework reclaiming unlinked dinodes 2010-05-21 16:11:36 +01:00
lops.c GFS2: Various gfs2_logd improvements 2010-05-05 09:39:18 +01:00
lops.h [GFS2] Only do lo_incore_commit once 2008-03-31 10:39:54 +01:00
main.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq 2010-10-22 17:13:10 -07:00
Makefile GFS2: Rename eattr.[ch] as xattr.[ch] 2009-08-26 18:51:04 +01:00
meta_io.c writeback: remove nonblocking/encountered_congestion references 2010-10-26 16:52:05 -07:00
meta_io.h GFS2: Metadata address space clean up 2010-03-01 14:07:37 +00:00
ops_fstype.c convert gfs2 2010-10-29 04:17:16 -04:00
ops_inode.c new helper: ihold() 2010-10-25 21:26:11 -04:00
quota.c GFS2: Userland expects quota limit/warn/usage in 512b blocks 2010-11-19 11:20:29 +00:00
quota.h mm: add context argument to shrinker callback 2010-07-19 14:56:17 +10:00
recovery.c GFS2: Fix spectator umount issue 2010-09-29 14:20:52 +01:00
recovery.h gfs2: use workqueue instead of slow-work 2010-07-23 13:14:25 +02:00
rgrp.c GFS2: Fix inode deallocation race 2010-11-15 12:44:42 +00:00
rgrp.h GFS2 fatal: filesystem consistency error on rename 2010-09-30 17:23:03 +01:00
super.c fs: icache RCU free inodes 2011-01-07 17:50:26 +11:00
super.h gfs: constify xattr_handler 2010-05-21 18:31:20 -04:00
sys.c GFS2: Fix type mapping for demote_rq interface 2010-10-06 09:58:44 +01:00
sys.h GFS2: Remove ancient, unused code 2009-01-05 07:39:13 +00:00
trace_gfs2.h GFS2: Don't enforce min hold time when two demotes occur in rapid succession 2010-09-20 11:19:50 +01:00
trans.c GFS2: Various gfs2_logd improvements 2010-05-05 09:39:18 +01:00
trans.h GFS2: reserve more blocks for transactions 2010-09-28 09:44:24 +01:00
util.c include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 2010-03-30 22:02:32 +09:00
util.h GFS2: Metadata address space clean up 2010-03-01 14:07:37 +00:00
xattr.c GFS2: reserve more blocks for transactions 2010-09-28 09:44:24 +01:00
xattr.h sanitize xattr handler prototypes 2009-12-16 12:16:49 -05:00