The patch titled ext4: allocate ->s_blockgroup_lock separately has been removed from the -mm tree. Its filename was ext4-allocate-s_blockgroup_lock-separately.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: ext4: allocate ->s_blockgroup_lock separately From: Pekka Enberg <penberg@xxxxxxxxxxxxxx> As spotted by kmemtrace, struct ext4_sb_info is 17664 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 ext4_sb_info enough to fit a 2 KB slab cache so now we allocate 16 KB + 2 KB instead of 32 KB saving 14 KB of memory. Acked-by: Andreas Dilger <adilger@xxxxxxx> Signed-off-by: Pekka Enberg <penberg@xxxxxxxxxxxxxx> Cc: <linux-ext4@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/ext4/ext4_sb.h | 4 ++-- fs/ext4/super.c | 10 +++++++++- 2 files changed, 11 insertions(+), 3 deletions(-) diff -puN fs/ext4/ext4_sb.h~ext4-allocate-s_blockgroup_lock-separately fs/ext4/ext4_sb.h --- a/fs/ext4/ext4_sb.h~ext4-allocate-s_blockgroup_lock-separately +++ a/fs/ext4/ext4_sb.h @@ -62,7 +62,7 @@ struct ext4_sb_info { struct percpu_counter s_freeinodes_counter; struct percpu_counter s_dirs_counter; struct percpu_counter s_dirtyblocks_counter; - struct blockgroup_lock s_blockgroup_lock; + struct blockgroup_lock *s_blockgroup_lock; struct proc_dir_entry *s_proc; /* Journaling */ @@ -149,7 +149,7 @@ struct ext4_sb_info { static inline spinlock_t * sb_bgl_lock(struct ext4_sb_info *sbi, unsigned int block_group) { - return bgl_lock_ptr(&sbi->s_blockgroup_lock, block_group); + return bgl_lock_ptr(sbi->s_blockgroup_lock, block_group); } #endif /* _EXT4_SB */ diff -puN fs/ext4/super.c~ext4-allocate-s_blockgroup_lock-separately fs/ext4/super.c --- a/fs/ext4/super.c~ext4-allocate-s_blockgroup_lock-separately +++ a/fs/ext4/super.c @@ -615,6 +615,7 @@ static void ext4_put_super(struct super_ ext4_blkdev_remove(sbi); } sb->s_fs_info = NULL; + kfree(sbi->s_blockgroup_lock); kfree(sbi); return; } @@ -2021,6 +2022,13 @@ static int ext4_fill_super(struct super_ 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 = EXT4_DEF_RESUID; @@ -2332,7 +2340,7 @@ static int ext4_fill_super(struct super_ &sbi->s_inode_readahead_blks); #endif - 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, logical_sb_block, i); _ Patches currently in -mm which might be from penberg@xxxxxxxxxxxxxx are repeatable-slab-corruption-with-ltp-msgctl08.patch linux-next.patch cifs-use-kzfree.patch md-use-kzfree.patch s390-use-kzfree.patch usb-use-kzfree.patch crypto-use-kzfree.patch mm-fix-lazy-vmap-purging-use-after-free-error.patch oom_kill-dont-call-for-int_sqrt0.patch ecryptfs-use-kzfree.patch nilfs2-integrated-block-mapping-remove-nilfs-bmap-wrapper-macros.patch nilfs2-integrated-block-mapping-remove-nilfs-bmap-wrapper-macros-checkpatch-fixes.patch nilfs2-avoid-double-error-caused-by-nilfs_transaction_end.patch nilfs2-clean-up-indirect-function-calling-conventions.patch nilfs2-use-unlocked_ioctl.patch nilfs2-replace-bug_on-and-bug-calls-triggerable-from-ioctl.patch slab-leaks3-default-y.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html