On Mon, Apr 09, 2012 at 05:20:46PM -0400, Calvin Walton wrote: > On Mon, 2012-04-09 at 16:54 -0400, Josef Bacik wrote: > > On Mon, Apr 09, 2012 at 01:10:04PM -0400, Calvin Walton wrote: > > > On Mon, 2012-04-09 at 11:53 -0400, Calvin Walton wrote: > > > > Hi, > > > > > > > > I have a system that's using a dracut-generated initramfs to mount a > > > > btrfs root. After upgrading to kernel 3.4.0-rc2 to test it out, I've > > > > noticed that the process of mounting the root filesystem takes much > > > > longer with 3.4.0-rc2 than it did with 3.3.1 - nearly 30 seconds slower! > > > > And the bisect results are in: > > > 285ff5af6ce358e73f53b55c9efadd4335f4c2ff is the first bad commit > > > commit 285ff5af6ce358e73f53b55c9efadd4335f4c2ff > > > Author: Josef Bacik <jo...@redhat.com> > > > Date: Fri Jan 13 15:27:45 2012 -0500 > > > > > > Btrfs: remove the ideal caching code> > > > > Ok can you give this a whirl? You are going to have to boot/reboot a few > > times > > to let the cache get re-generated again to make sure it's taken effect, but > > hopefully this will help out. Thanks, > > Unfortunately, it doesn't seem to help. Even after 3 or 4 reboots with > this patch applied I'm still seeing the same delay. >
Ok drop that previous patch and give this one a whirl, it helped on my laptop. This is only half of the problem AFAICS, but it's the easier half to fix, in the meantime I need to lock down why we're not writing out cache for a bunch of block groups, but thats trickier since the messages I need are spit out while I'm shutting down, so I need to get creative. Let me know if/how much this helps. Thanks, Josef diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a844204..4a871f0 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -529,9 +529,7 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, * allocate blocks for the tree root we can't do the fast caching since * we likely hold important locks. */ - if (trans && (!trans->transaction->in_commit) && - (root && root != root->fs_info->tree_root) && - btrfs_test_opt(root, SPACE_CACHE)) { + if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) { ret = load_free_space_cache(fs_info, cache); spin_lock(&cache->lock); diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 054707e..baaa518 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -748,13 +748,6 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, u64 used = btrfs_block_group_used(&block_group->item); /* - * If we're unmounting then just return, since this does a search on the - * normal root and not the commit root and we could deadlock. - */ - if (btrfs_fs_closing(fs_info)) - return 0; - - /* * If this block group has been marked to be cleared for one reason or * another then we can't trust the on disk cache, so just return. */ @@ -768,6 +761,8 @@ int load_free_space_cache(struct btrfs_fs_info *fs_info, path = btrfs_alloc_path(); if (!path) return 0; + path->search_commit_root = 1; + path->skip_locking = 1; inode = lookup_free_space_inode(root, block_group, path); if (IS_ERR(inode)) { -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html