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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 /include | |
| parent | beed5ecbaa377fa8bb6a54a6608e8725a21efdbc (diff) | |
| download | linux-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>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions