From: Dave Chinner <dchinner@xxxxxxxxxx> 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@xxxxxxxxxx> --- Documentation/filesystems/vfs.txt | 6 ++++++ fs/super.c | 1 + 2 files changed, 7 insertions(+), 0 deletions(-) diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index fd24f34..6bf85b7 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. diff --git a/fs/super.c b/fs/super.c index ca8e735..c1e0836 100644 --- a/fs/super.c +++ b/fs/super.c @@ -183,6 +183,7 @@ static struct super_block *alloc_super(struct file_system_type *type) s->s_shrink.seeks = DEFAULT_SEEKS; s->s_shrink.shrink = prune_super; + s->s_shrink.batch = 1024; } out: return s; -- 1.7.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
