From: Amir Goldstein Date: Tue, 4 Oct 2022 10:34:33 +0000 (+0300) Subject: ovl: use plain list filler in indexdir and workdir cleanup X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=af4dcb6d78b2b05a0431dfd3f67713bba8dc0900;p=linux.git ovl: use plain list filler in indexdir and workdir cleanup Those two cleanup routines are using the helper ovl_dir_read() with the merge dir filler, which populates an rb tree, that is never used. The index dir entry names all have a long (42 bytes) constant prefix, so it is not surprising that perf top has demostrated high CPU usage by rb tree population during cleanup of a large index dir: - 9.53% ovl_fill_merge - 78.41% ovl_cache_entry_find_link.constprop.27 + 72.11% strncmp Use the plain list filler that does not populate the unneeded rb tree. Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi --- diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c index 2b210640036c4..31227e2d85e4f 100644 --- a/fs/overlayfs/readdir.c +++ b/fs/overlayfs/readdir.c @@ -1071,14 +1071,10 @@ static int ovl_workdir_cleanup_recurse(struct ovl_fs *ofs, const struct path *pa int err; struct inode *dir = path->dentry->d_inode; LIST_HEAD(list); - struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { - .ctx.actor = ovl_fill_merge, - .dentry = NULL, + .ctx.actor = ovl_fill_plain, .list = &list, - .root = &root, - .is_lowest = false, }; bool incompat = false; @@ -1159,14 +1155,10 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs) struct inode *dir = indexdir->d_inode; struct path path = { .mnt = ovl_upper_mnt(ofs), .dentry = indexdir }; LIST_HEAD(list); - struct rb_root root = RB_ROOT; struct ovl_cache_entry *p; struct ovl_readdir_data rdd = { - .ctx.actor = ovl_fill_merge, - .dentry = NULL, + .ctx.actor = ovl_fill_plain, .list = &list, - .root = &root, - .is_lowest = false, }; err = ovl_dir_read(&path, &rdd);