diff options
| author | Dave Chinner <dchinner@redhat.com> | 2011-07-08 14:14:45 +1000 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-20 20:47:41 -0400 |
| commit | 8ab47664d51a69ea79fe70bb07ca80664f74f76b (patch) | |
| tree | a0cc73a909840edfb23b4b4490c39fd222cce0fa /Documentation/filesystems/vfs.txt | |
| parent | 0e1fdafd93980eac62e778798549ce0f6073905c (diff) | |
vfs: increase shrinker batch size
Now that the per-sb shrinker is responsible for shrinking 2 or more
caches, increase the batch size to keep econmies of scale for
shrinking each cache. Increase the shrinker batch size to 1024
objects.
To allow for a large increase in batch size, add a conditional
reschedule to prune_icache_sb() so that we don't hold the LRU spin
lock for too long. This mirrors the behaviour of the
__shrink_dcache_sb(), and allows us to increase the batch size
without needing to worry about problems caused by long lock hold
times.
To ensure that filesystems using the per-sb shrinker callouts don't
cause problems, document that the object freeing method must
reschedule appropriately inside loops.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation/filesystems/vfs.txt')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index fd24f34f120f..6bf85b78cfea 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -317,6 +317,12 @@ or bottom half). the VM is trying to reclaim under GFP_NOFS conditions, hence this method does not need to handle that situation itself. + Implementations must include conditional reschedule calls inside any + scanning loop that is done. This allows the VFS to determine + appropriate scan batch sizes without having to worry about whether + implementations will cause holdoff problems due to large scan batch + sizes. + Whoever sets up the inode is responsible for filling in the "i_op" field. This is a pointer to a "struct inode_operations" which describes the methods that can be performed on individual inodes. |