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| author | Dmitry Monakhov <dmonakhov@openvz.org> | 2010-10-27 22:08:46 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2010-10-27 22:08:46 -0400 |
| commit | 3d287de3b828226e5a450c7fd5bf4283792dc2b0 (patch) | |
| tree | 4adcc534e2042aed924750df3ef2433bd2f14fd8 | |
| parent | beed5ecbaa377fa8bb6a54a6608e8725a21efdbc (diff) | |
| download | kernel_samsung_smdk4412-3d287de3b828226e5a450c7fd5bf4283792dc2b0.zip kernel_samsung_smdk4412-3d287de3b828226e5a450c7fd5bf4283792dc2b0.tar.gz kernel_samsung_smdk4412-3d287de3b828226e5a450c7fd5bf4283792dc2b0.tar.bz2 | |
ext4: optimize orphan_list handling for ext4_setattr
Surprisingly chown() on ext4 is not SMP scalable operation.
Due to unconditional orphan_del(NULL, inode) in ext4_setattr()
result in significant performance overhead because of global orphan
mutex, especially in no-journal mode (where orphan_add() is noop).
It is possible to skip explicit orphan_del if possible.
Results of fchown() micro-benchmark in no-journal mode
while (1) {
iteration++;
fchown(fd, uid, gid);
fchown(fd, uid + 1, gid + 1)
}
measured: iterations per millisecond
| nr_tasks | w/o patch | with patch |
| 1 | 142 | 185 |
| 4 | 109 | 642 |
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
| -rw-r--r-- | fs/ext4/inode.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9e60d0b..3ba237b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -5281,6 +5281,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = dentry->d_inode; int error, rc = 0; + int orphan = 0; const unsigned int ia_valid = attr->ia_valid; error = inode_change_ok(inode, attr); @@ -5336,8 +5337,10 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) error = PTR_ERR(handle); goto err_out; } - - error = ext4_orphan_add(handle, inode); + if (ext4_handle_valid(handle)) { + error = ext4_orphan_add(handle, inode); + orphan = 1; + } EXT4_I(inode)->i_disksize = attr->ia_size; rc = ext4_mark_inode_dirty(handle, inode); if (!error) @@ -5355,6 +5358,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) goto err_out; } ext4_orphan_del(handle, inode); + orphan = 0; ext4_journal_stop(handle); goto err_out; } @@ -5377,7 +5381,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr) * If the call to ext4_truncate failed to get a transaction handle at * all, we need to clean up the in-core orphan list manually. */ - if (inode->i_nlink) + if (orphan && inode->i_nlink) ext4_orphan_del(NULL, inode); if (!rc && (ia_valid & ATTR_MODE)) |