projects/linux·commit 833f7329

[PATCH] EXT2: Remove superblock lock contention in ext2_statfs

833f7329 · Dave Kleikamp <[email protected]> · 2006-09-18 20:12:33 -07:00

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 <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Commit
833f73299fdf4497af1552e219e95661f4d2cdca
Parents
ac7fb273

Changes

3 files changed · +0 −4

FileStatusAddDelContent
fs/ext2/balloc.cmodified+0−1View file
fs/ext2/ialloc.cmodified+0−1View file
fs/ext2/super.cmodified+0−2View file

fs/ext2/balloc.c

View file
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index d487043..b1981d0 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;

fs/ext2/ialloc.c

View file
diff --git a/fs/ext2/ialloc.c b/fs/ext2/ialloc.c
index de85c61..695f69c 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;

fs/ext2/super.c

View file
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index ca5bfb6..4286ff6 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;
}