The patch titled fs/inode.c: properly init address_space->writeback_index has been removed from the -mm tree. Its filename was fs-inodec-properly-init-address_space-writeback_index.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: fs/inode.c: properly init address_space->writeback_index From: Chris Mason <chris.mason@xxxxxxxxxx> write_cache_pages() uses i_mapping->writeback_index to pick up where it left off the last time a given inode was found by pdflush or balance_dirty_pages (or anyone else who sets wbc->range_cyclic) alloc_inode() should set it to a sane value so that writeback doesn't start in the middle of a file. It is somewhat difficult to notice the bug since write_cache_pages will loop around to the start of the file and the elevator helps hide the resulting seeks. For whatever reason, Btrfs hits this often. Unpatched, untarring 30 copies of the linux kernel in series runs at 47MB/s on a single sata drive. With this fix, it jumps to 62MB/s. Signed-off-by: Chris Mason <chris.mason@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/inode.c | 1 + 1 file changed, 1 insertion(+) diff -puN fs/inode.c~fs-inodec-properly-init-address_space-writeback_index fs/inode.c --- a/fs/inode.c~fs-inodec-properly-init-address_space-writeback_index +++ a/fs/inode.c @@ -166,6 +166,7 @@ static struct inode *alloc_inode(struct mapping_set_gfp_mask(mapping, GFP_HIGHUSER_PAGECACHE); mapping->assoc_mapping = NULL; mapping->backing_dev_info = &default_backing_dev_info; + mapping->writeback_index = 0; /* * If the block_device provides a backing_dev_info for client _ Patches currently in -mm which might be from chris.mason@xxxxxxxxxx are origin.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html