From mboxrd@z Thu Jan 1 00:00:00 1970 From: akpm@linux-foundation.org Subject: [patch 05/11] fs/block_dev.c: __read_mostly improvement and sb_is_blkdev_sb utilization Date: Mon, 01 Dec 2008 14:34:56 -0800 Message-ID: <200812012234.mB1MYu81021121@imap1.linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, crquan@gmail.com To: viro@zeniv.linux.org.uk Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:34008 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752365AbYLAWf2 (ORCPT ); Mon, 1 Dec 2008 17:35:28 -0500 Sender: linux-fsdevel-owner@vger.kernel.org List-ID: From: Denis ChengRq - iget5_locked in bdget really needs blockdev_superblock, instead of bd_mnt, so bd_mnt could be just a local variable; - blockdev_superblock really needs __read_mostly, while local var bd_mnt not; - make use of sb_is_blkdev_sb in bd_forget, instead of direct reference to blockdev_superblock. Signed-off-by: Denis ChengRq Cc: Al Viro Signed-off-by: Andrew Morton --- fs/block_dev.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff -puN fs/block_dev.c~fs-block_devc-__read_mostly-improvement-and-sb_is_blkdev_sb-utilization fs/block_dev.c --- a/fs/block_dev.c~fs-block_devc-__read_mostly-improvement-and-sb_is_blkdev_sb-utilization +++ a/fs/block_dev.c @@ -326,12 +326,13 @@ static struct file_system_type bd_type = .kill_sb = kill_anon_super, }; -static struct vfsmount *bd_mnt __read_mostly; -struct super_block *blockdev_superblock; +struct super_block *blockdev_superblock __read_mostly; void __init bdev_cache_init(void) { int err; + struct vfsmount *bd_mnt; + bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| SLAB_MEM_SPREAD|SLAB_PANIC), @@ -373,7 +374,7 @@ struct block_device *bdget(dev_t dev) struct block_device *bdev; struct inode *inode; - inode = iget5_locked(bd_mnt->mnt_sb, hash(dev), + inode = iget5_locked(blockdev_superblock, hash(dev), bdev_test, bdev_set, &dev); if (!inode) @@ -463,7 +464,7 @@ void bd_forget(struct inode *inode) spin_lock(&bdev_lock); if (inode->i_bdev) { - if (inode->i_sb != blockdev_superblock) + if (!sb_is_blkdev_sb(inode->i_sb)) bdev = inode->i_bdev; __bd_forget(inode); } _