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| author | Pekka Enberg <penberg@cs.helsinki.fi> | 2009-01-07 18:07:25 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-08 08:31:00 -0800 |
| commit | 5df096d67ec2b6578518caed7d57317a4b807aa1 (patch) | |
| tree | 8e92d19c89dea347eed6fc018fc6e4388bf9ebdc /fs | |
| parent | f420d4dc4272fd223986762df2ad06056ddebada (diff) | |
| download | lwn-5df096d67ec2b6578518caed7d57317a4b807aa1.tar.gz lwn-5df096d67ec2b6578518caed7d57317a4b807aa1.zip | |
ext3: allocate ->s_blockgroup_lock separately
As spotted by kmemtrace, struct ext3_sb_info is 17152 bytes on 64-bit
which makes it a very bad fit for SLAB allocators. The culprit of the
wasted memory is ->s_blockgroup_lock which can be as big as 16 KB when
NR_CPUS >= 32.
To fix that, allocate ->s_blockgroup_lock, which fits nicely in a order 2
page in the worst case, separately. This shinks down struct ext3_sb_info
enough to fit a 1 KB slab cache so now we allocate 16 KB + 1 KB instead of
32 KB saving 15 KB of memory.
Acked-by: Andreas Dilger <adilger@sun.com>
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext3/super.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/fs/ext3/super.c b/fs/ext3/super.c index c22d01467bd1..01c235bc2054 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -439,6 +439,7 @@ static void ext3_put_super (struct super_block * sb) ext3_blkdev_remove(sbi); } sb->s_fs_info = NULL; + kfree(sbi->s_blockgroup_lock); kfree(sbi); return; } @@ -1546,6 +1547,13 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) sbi = kzalloc(sizeof(*sbi), GFP_KERNEL); if (!sbi) return -ENOMEM; + + sbi->s_blockgroup_lock = + kzalloc(sizeof(struct blockgroup_lock), GFP_KERNEL); + if (!sbi->s_blockgroup_lock) { + kfree(sbi); + return -ENOMEM; + } sb->s_fs_info = sbi; sbi->s_mount_opt = 0; sbi->s_resuid = EXT3_DEF_RESUID; @@ -1786,7 +1794,7 @@ static int ext3_fill_super (struct super_block *sb, void *data, int silent) goto failed_mount; } - bgl_lock_init(&sbi->s_blockgroup_lock); + bgl_lock_init(sbi->s_blockgroup_lock); for (i = 0; i < db_count; i++) { block = descriptor_loc(sb, logic_sb_block, i); |