From: Dave Kleikamp Date: Tue, 19 Sep 2006 03:12:33 +0000 (-0700) Subject: [PATCH] EXT2: Remove superblock lock contention in ext2_statfs X-Git-Tag: v2.6.18~5 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=833f73299fdf4497af1552e219e95661f4d2cdca;p=linux-2.6-omap-h63xx.git [PATCH] EXT2: Remove superblock lock contention in ext2_statfs Fix a performance degradation introduced in 2.6.17. (30% degradation running dbench with 16 threads) Commit 21730eed11de42f22afcbd43f450a1872a0b5ea1, which claims to make EXT2_DEBUG work again, moves the taking of the kernel lock out of debug-only code in ext2_count_free_inodes and ext2_count_free_blocks and into ext2_statfs. The same problem was fixed in ext3 by removing the lock completely (commit 5b11687924e40790deb0d5f959247ade82196665) Signed-off-by: Dave Kleikamp Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c index d4870432ecf..b1981d0e95a 100644 --- a/fs/ext2/balloc.c +++ b/fs/ext2/balloc.c @@ -539,7 +539,6 @@ unsigned long ext2_count_free (struct buffer_head * map, unsigned int numchars) #endif /* EXT2FS_DEBUG */ -/* Superblock must be locked */ unsigned long ext2_count_free_blocks (struct super_block * sb) { struct ext2_group_desc * desc; diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c index de85c61c58c..695f69ccf90 100644 --- a/fs/ext2/ialloc.c +++ b/fs/ext2/ialloc.c @@ -637,7 +637,6 @@ fail: return ERR_PTR(err); } -/* Superblock must be locked */ unsigned long ext2_count_free_inodes (struct super_block * sb) { struct ext2_group_desc *desc; diff --git a/fs/ext2/super.c b/fs/ext2/super.c index ca5bfb6914d..4286ff6330b 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -1083,7 +1083,6 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) unsigned long overhead; int i; - lock_super(sb); if (test_opt (sb, MINIX_DF)) overhead = 0; else { @@ -1124,7 +1123,6 @@ static int ext2_statfs (struct dentry * dentry, struct kstatfs * buf) buf->f_files = le32_to_cpu(sbi->s_es->s_inodes_count); buf->f_ffree = ext2_count_free_inodes (sb); buf->f_namelen = EXT2_NAME_LEN; - unlock_super(sb); return 0; }