Kirill A. Shutemov
2012-Jun-08 21:28 UTC
[RFC, PATCH] fs: push rcu_barrier() from deactivate_locked_super() to filesystems
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> There''s no reason to call rcu_barrier() on every deactivate_locked_super(). We only need to make sure that all delayed rcu free inodes are flushed before we destroy related cache. Removing rcu_barrier() from deactivate_locked_super() affects some fas paths. E.g. on my machine exit_group() of a last process in IPC namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> --- fs/9p/v9fs.c | 5 +++++ fs/adfs/super.c | 5 +++++ fs/affs/super.c | 5 +++++ fs/afs/super.c | 5 +++++ fs/befs/linuxvfs.c | 5 +++++ fs/bfs/inode.c | 5 +++++ fs/btrfs/extent_io.c | 6 ++++++ fs/btrfs/inode.c | 5 +++++ fs/ceph/super.c | 5 +++++ fs/cifs/cifsfs.c | 5 +++++ fs/coda/inode.c | 5 +++++ fs/ecryptfs/main.c | 6 ++++++ fs/efs/super.c | 5 +++++ fs/exofs/super.c | 5 +++++ fs/ext2/super.c | 5 +++++ fs/ext3/super.c | 5 +++++ fs/ext4/super.c | 5 +++++ fs/fat/inode.c | 5 +++++ fs/freevxfs/vxfs_super.c | 5 +++++ fs/fuse/inode.c | 6 ++++++ fs/hfs/super.c | 6 ++++++ fs/hfsplus/super.c | 6 ++++++ fs/hpfs/super.c | 5 +++++ fs/hugetlbfs/inode.c | 5 +++++ fs/isofs/inode.c | 5 +++++ fs/jffs2/super.c | 6 ++++++ fs/jfs/super.c | 6 ++++++ fs/logfs/inode.c | 5 +++++ fs/minix/inode.c | 5 +++++ fs/ncpfs/inode.c | 5 +++++ fs/nfs/inode.c | 5 +++++ fs/nilfs2/super.c | 6 ++++++ fs/ntfs/super.c | 6 ++++++ fs/ocfs2/dlmfs/dlmfs.c | 5 +++++ fs/ocfs2/super.c | 5 +++++ fs/openpromfs/inode.c | 5 +++++ fs/qnx4/inode.c | 5 +++++ fs/qnx6/inode.c | 5 +++++ fs/reiserfs/super.c | 5 +++++ fs/romfs/super.c | 5 +++++ fs/squashfs/super.c | 5 +++++ fs/super.c | 6 ------ fs/sysv/inode.c | 5 +++++ fs/ubifs/super.c | 6 ++++++ fs/udf/super.c | 5 +++++ fs/ufs/super.c | 5 +++++ fs/xfs/xfs_super.c | 5 +++++ 47 files changed, 240 insertions(+), 6 deletions(-) diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c index b85efa7..392c5da 100644 --- a/fs/9p/v9fs.c +++ b/fs/9p/v9fs.c @@ -560,6 +560,11 @@ static int v9fs_init_inode_cache(void) */ static void v9fs_destroy_inode_cache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(v9fs_inode_cache); } diff --git a/fs/adfs/super.c b/fs/adfs/super.c index 06fdcc9..f137165 100644 --- a/fs/adfs/super.c +++ b/fs/adfs/super.c @@ -276,6 +276,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(adfs_inode_cachep); } diff --git a/fs/affs/super.c b/fs/affs/super.c index 0782653..4fe18a8 100644 --- a/fs/affs/super.c +++ b/fs/affs/super.c @@ -129,6 +129,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(affs_inode_cachep); } diff --git a/fs/afs/super.c b/fs/afs/super.c index f02b31e..af69050 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -123,6 +123,11 @@ void __exit afs_fs_exit(void) BUG(); } + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(afs_inode_cachep); _leave(""); } diff --git a/fs/befs/linuxvfs.c b/fs/befs/linuxvfs.c index e18da23..02f3331 100644 --- a/fs/befs/linuxvfs.c +++ b/fs/befs/linuxvfs.c @@ -454,6 +454,11 @@ befs_init_inodecache(void) static void befs_destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(befs_inode_cachep); } diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c index 9870417..d5fc598 100644 --- a/fs/bfs/inode.c +++ b/fs/bfs/inode.c @@ -280,6 +280,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(bfs_inode_cachep); } diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index 2c8f7b2..010623a 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -106,6 +106,12 @@ void extent_io_exit(void) list_del(&eb->leak_list); kmem_cache_free(extent_buffer_cache, eb); } + + /* + * Make sure all delayed rcu free are flushed before we + * destroy caches. + */ + rcu_barrier(); if (extent_state_cache) kmem_cache_destroy(extent_state_cache); if (extent_buffer_cache) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index f6ab6f5..971d222 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -6976,6 +6976,11 @@ static void init_once(void *foo) void btrfs_destroy_cachep(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); if (btrfs_inode_cachep) kmem_cache_destroy(btrfs_inode_cachep); if (btrfs_trans_handle_cachep) diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 1e67dd7..ecc251e 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -602,6 +602,11 @@ bad_cap: static void destroy_caches(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ceph_inode_cachep); kmem_cache_destroy(ceph_cap_cachep); kmem_cache_destroy(ceph_dentry_cachep); diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 8b6e344..93ce9b3f 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -975,6 +975,11 @@ cifs_init_inodecache(void) static void cifs_destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(cifs_inode_cachep); } diff --git a/fs/coda/inode.c b/fs/coda/inode.c index f181312..0c70460 100644 --- a/fs/coda/inode.c +++ b/fs/coda/inode.c @@ -85,6 +85,11 @@ int coda_init_inodecache(void) void coda_destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(coda_inode_cachep); } diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index 6895493..f6acf8a 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -693,6 +693,12 @@ static void ecryptfs_free_kmem_caches(void) { int i; + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + for (i = 0; i < ARRAY_SIZE(ecryptfs_cache_infos); i++) { struct ecryptfs_cache_info *info; diff --git a/fs/efs/super.c b/fs/efs/super.c index e755ec7..2002431 100644 --- a/fs/efs/super.c +++ b/fs/efs/super.c @@ -96,6 +96,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(efs_inode_cachep); } diff --git a/fs/exofs/super.c b/fs/exofs/super.c index 4337836..d271f96 100644 --- a/fs/exofs/super.c +++ b/fs/exofs/super.c @@ -206,6 +206,11 @@ static int init_inodecache(void) */ static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(exofs_inode_cachep); } diff --git a/fs/ext2/super.c b/fs/ext2/super.c index b3621cb..de2051c 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -204,6 +204,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ext2_inode_cachep); } diff --git a/fs/ext3/super.c b/fs/ext3/super.c index 8c3a44b..bd60e08 100644 --- a/fs/ext3/super.c +++ b/fs/ext3/super.c @@ -543,6 +543,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ext3_inode_cachep); } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index eb7aa3e..4e2aacb 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1046,6 +1046,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ext4_inode_cachep); } diff --git a/fs/fat/inode.c b/fs/fat/inode.c index a3d81eb..35113bc 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -526,6 +526,11 @@ static int __init fat_init_inodecache(void) static void __exit fat_destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(fat_inode_cachep); } diff --git a/fs/freevxfs/vxfs_super.c b/fs/freevxfs/vxfs_super.c index d4fabd2..fed2c8a 100644 --- a/fs/freevxfs/vxfs_super.c +++ b/fs/freevxfs/vxfs_super.c @@ -279,6 +279,11 @@ static void __exit vxfs_cleanup(void) { unregister_filesystem(&vxfs_fs_type); + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(vxfs_inode_cachep); } diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 1cd6165..9078173 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -1171,6 +1171,12 @@ static void fuse_fs_cleanup(void) { unregister_filesystem(&fuse_fs_type); unregister_fuseblk(); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(fuse_inode_cachep); } diff --git a/fs/hfs/super.c b/fs/hfs/super.c index 7b4c537..373a9e5 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -483,6 +483,12 @@ static int __init init_hfs_fs(void) static void __exit exit_hfs_fs(void) { unregister_filesystem(&hfs_fs_type); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(hfs_inode_cachep); } diff --git a/fs/hfsplus/super.c b/fs/hfsplus/super.c index a9bca4b..bde9ecf 100644 --- a/fs/hfsplus/super.c +++ b/fs/hfsplus/super.c @@ -615,6 +615,12 @@ static int __init init_hfsplus_fs(void) static void __exit exit_hfsplus_fs(void) { unregister_filesystem(&hfsplus_fs_type); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(hfsplus_inode_cachep); } diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c index 706a12c..3cb1da5 100644 --- a/fs/hpfs/super.c +++ b/fs/hpfs/super.c @@ -210,6 +210,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(hpfs_inode_cachep); } diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c index cc9281b..b482175 100644 --- a/fs/hugetlbfs/inode.c +++ b/fs/hugetlbfs/inode.c @@ -1042,6 +1042,11 @@ static int __init init_hugetlbfs_fs(void) static void __exit exit_hugetlbfs_fs(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(hugetlbfs_inode_cachep); kern_unmount(hugetlbfs_vfsmount); unregister_filesystem(&hugetlbfs_fs_type); diff --git a/fs/isofs/inode.c b/fs/isofs/inode.c index 29037c3..f94cde4 100644 --- a/fs/isofs/inode.c +++ b/fs/isofs/inode.c @@ -114,6 +114,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(isofs_inode_cachep); } diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index 61ea413..ff48795 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -418,6 +418,12 @@ static void __exit exit_jffs2_fs(void) unregister_filesystem(&jffs2_fs_type); jffs2_destroy_slab_caches(); jffs2_compressors_exit(); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(jffs2_inode_cachep); } diff --git a/fs/jfs/super.c b/fs/jfs/super.c index 4a82950..2fc7602 100644 --- a/fs/jfs/super.c +++ b/fs/jfs/super.c @@ -898,6 +898,12 @@ static void __exit exit_jfs_fs(void) jfs_proc_clean(); #endif unregister_filesystem(&jfs_fs_type); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(jfs_inode_cachep); } diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c index a422f42..3d1b9fa 100644 --- a/fs/logfs/inode.c +++ b/fs/logfs/inode.c @@ -401,5 +401,10 @@ int logfs_init_inode_cache(void) void logfs_destroy_inode_cache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(logfs_inode_cache); } diff --git a/fs/minix/inode.c b/fs/minix/inode.c index 2a503ad..dc8d362 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -100,6 +100,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(minix_inode_cachep); } diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c index 333df07..0c62c55 100644 --- a/fs/ncpfs/inode.c +++ b/fs/ncpfs/inode.c @@ -89,6 +89,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ncp_inode_cachep); } diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c index e605d69..39aae2e 100644 --- a/fs/nfs/inode.c +++ b/fs/nfs/inode.c @@ -1566,6 +1566,11 @@ static int __init nfs_init_inodecache(void) static void nfs_destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(nfs_inode_cachep); } diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index 1099a76..956e5a4 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -1386,6 +1386,12 @@ static void nilfs_segbuf_init_once(void *obj) static void nilfs_destroy_cachep(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); + if (nilfs_inode_cachep) kmem_cache_destroy(nilfs_inode_cachep); if (nilfs_transaction_cachep) diff --git a/fs/ntfs/super.c b/fs/ntfs/super.c index b341492..ecc8625 100644 --- a/fs/ntfs/super.c +++ b/fs/ntfs/super.c @@ -3185,6 +3185,12 @@ static void __exit exit_ntfs_fs(void) ntfs_debug("Unregistering NTFS driver."); unregister_filesystem(&ntfs_fs_type); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ntfs_big_inode_cache); kmem_cache_destroy(ntfs_inode_cache); kmem_cache_destroy(ntfs_name_cache); diff --git a/fs/ocfs2/dlmfs/dlmfs.c b/fs/ocfs2/dlmfs/dlmfs.c index e31d6ae..6934459 100644 --- a/fs/ocfs2/dlmfs/dlmfs.c +++ b/fs/ocfs2/dlmfs/dlmfs.c @@ -691,6 +691,11 @@ static void __exit exit_dlmfs_fs(void) flush_workqueue(user_dlm_worker); destroy_workqueue(user_dlm_worker); + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(dlmfs_inode_cache); bdi_destroy(&dlmfs_backing_dev_info); diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 68f4541..0e91ec2 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -1818,6 +1818,11 @@ static int ocfs2_initialize_mem_caches(void) static void ocfs2_free_mem_caches(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); if (ocfs2_inode_cachep) kmem_cache_destroy(ocfs2_inode_cachep); ocfs2_inode_cachep = NULL; diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c index bc49c97..1b76370 100644 --- a/fs/openpromfs/inode.c +++ b/fs/openpromfs/inode.c @@ -463,6 +463,11 @@ static int __init init_openprom_fs(void) static void __exit exit_openprom_fs(void) { unregister_filesystem(&openprom_fs_type); + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(op_inode_cachep); } diff --git a/fs/qnx4/inode.c b/fs/qnx4/inode.c index 552e994..9534b4f 100644 --- a/fs/qnx4/inode.c +++ b/fs/qnx4/inode.c @@ -391,6 +391,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(qnx4_inode_cachep); } diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c index e44012d..3cba5d2 100644 --- a/fs/qnx6/inode.c +++ b/fs/qnx6/inode.c @@ -652,6 +652,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(qnx6_inode_cachep); } diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c index 651ce76..ad39139 100644 --- a/fs/reiserfs/super.c +++ b/fs/reiserfs/super.c @@ -603,6 +603,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(reiserfs_inode_cachep); } diff --git a/fs/romfs/super.c b/fs/romfs/super.c index e64f6b5..f901eaf 100644 --- a/fs/romfs/super.c +++ b/fs/romfs/super.c @@ -648,6 +648,11 @@ error_register: static void __exit exit_romfs_fs(void) { unregister_filesystem(&romfs_fs_type); + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(romfs_inode_cachep); } diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c index 29cd014..260e392 100644 --- a/fs/squashfs/super.c +++ b/fs/squashfs/super.c @@ -425,6 +425,11 @@ static int __init init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(squashfs_inode_cachep); } diff --git a/fs/super.c b/fs/super.c index cf00177..2d962aa 100644 --- a/fs/super.c +++ b/fs/super.c @@ -256,12 +256,6 @@ void deactivate_locked_super(struct super_block *s) /* caches are now gone, we can safely kill the shrinker now */ unregister_shrinker(&s->s_shrink); - - /* - * We need to call rcu_barrier so all the delayed rcu free - * inodes are flushed before we release the fs module. - */ - rcu_barrier(); put_filesystem(fs); put_super(s); } else { diff --git a/fs/sysv/inode.c b/fs/sysv/inode.c index 08d0b25..a08341c 100644 --- a/fs/sysv/inode.c +++ b/fs/sysv/inode.c @@ -376,5 +376,10 @@ int __init sysv_init_icache(void) void sysv_destroy_icache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(sysv_inode_cachep); } diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 5862dd9..e8ae748 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2302,6 +2302,12 @@ static void __exit ubifs_exit(void) dbg_debugfs_exit(); ubifs_compressors_exit(); unregister_shrinker(&ubifs_shrinker_info); + + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ubifs_inode_slab); unregister_filesystem(&ubifs_fs_type); } diff --git a/fs/udf/super.c b/fs/udf/super.c index ac8a348..ebe9f52 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -170,6 +170,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(udf_inode_cachep); } diff --git a/fs/ufs/super.c b/fs/ufs/super.c index 302f340..f655c1d 100644 --- a/fs/ufs/super.c +++ b/fs/ufs/super.c @@ -1449,6 +1449,11 @@ static int init_inodecache(void) static void destroy_inodecache(void) { + /* + * Make sure all delayed rcu free inodes are flushed before we + * destroy cache. + */ + rcu_barrier(); kmem_cache_destroy(ufs_inode_cachep); } diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index 0d9de41..bbcbf2a 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -1582,6 +1582,11 @@ xfs_init_zones(void) STATIC void xfs_destroy_zones(void) { + /* + * Make sure all delayed rcu free are flushed before we + * destroy caches. + */ + rcu_barrier(); kmem_zone_destroy(xfs_ili_zone); kmem_zone_destroy(xfs_inode_zone); kmem_zone_destroy(xfs_efi_zone); -- 1.7.10 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/
Linus Torvalds
2012-Jun-08 21:43 UTC
[Ocfs2-devel] [RFC, PATCH] fs: push rcu_barrier() from deactivate_locked_super() to filesystems
On Fri, Jun 8, 2012 at 2:28 PM, Kirill A. Shutemov <kirill.shutemov at linux.intel.com> wrote:> From: "Kirill A. Shutemov" <kirill.shutemov at linux.intel.com> > > There's no reason to call rcu_barrier() on every deactivate_locked_super(). > We only need to make sure that all delayed rcu free inodes are flushed > before we destroy related cache. > > Removing rcu_barrier() from deactivate_locked_super() affects some > fas paths. E.g. on my machine exit_group() of a last process in IPC > namespace takes 0.07538s. rcu_barrier() takes 0.05188s of that time.I think we should just delete it. kmem_cache_destroy() (at least for SLUB) already has: if (s->flags & SLAB_DESTROY_BY_RCU) rcu_barrier(); in it. But I think it's too late - it gets called *after* we do kmem_cache_close(), and I get the feeling that we should do it before. Shouldn't that be sufficient? And if other slab allocators don't have this, we should add it to them too. Hmm? Linus