From 7f9838fd01833ffb30177d964983076924344c9e Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Thu, 21 Jul 2011 19:59:22 -0400 Subject: sysfs: count subdirectories sysfs: count subdirectories This patch introduces a subdirectory counter for each sysfs directory. Without the patch, sysfs_refresh_inode would walk all entries of the directory to calculate the number of subdirectories. This patch improves time of "ls -la /sys/block" when there are 10000 block devices from 9 seconds to 0.19 seconds. Signed-off-by: Mikulas Patocka Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'fs/sysfs/dir.c') diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index ea9120a830d8..7d240e6b7176 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -47,6 +47,9 @@ static void sysfs_link_sibling(struct sysfs_dirent *sd) BUG_ON(sd->s_sibling); + if (sysfs_type(sd) == SYSFS_DIR) + parent_sd->s_dir.subdirs++; + /* Store directory entries in order by ino. This allows * readdir to properly restart without having to add a * cursor into the s_dir.children list. @@ -73,6 +76,9 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) { struct sysfs_dirent **pos; + if (sysfs_type(sd) == SYSFS_DIR) + sd->s_parent->s_dir.subdirs--; + for (pos = &sd->s_parent->s_dir.children; *pos; pos = &(*pos)->s_sibling) { if (*pos == sd) { -- cgit v1.2.3-55-g7522