Commit d530148ae8bffe1b33f50d1776d185a6e85dc774
Committed by
Jan Kara
Jan Kara
1 parent
d56557af19
Exists in
master
and in
7 other branches
dquot: do full inode dirty in allocating space
Alex Shi found a regression when doing ffsb test. The test has several threads, and each thread creates a small file, write to it and then delete it. ffsb reports about 20% regression and Alex bisected it to 43d2932d88e4. The test will call __mark_inode_dirty 3 times. without this commit, we only take inode_lock one time, while with it, we take the lock 3 times with flags ( I_DIRTY_SYNC,I_DIRTY_PAGES,I_DIRTY). Perf shows the lock contention increased too much. Below proposed patch fixes it. fs is allocating blocks, which usually means file writes and the inode will be dirtied soon. We fully dirty the inode to reduce some inode_lock contention in several calls of __mark_inode_dirty. Jan Kara: Added comment. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Alex Shi <alex.shi@intel.com> Signed-off-by: Jan Kara <jack@suse.cz>
Showing 1 changed file with 8 additions and 2 deletions Side-by-side Diff
include/linux/quotaops.h
| ... | ... | @@ -274,8 +274,14 @@ |
| 274 | 274 | int ret; |
| 275 | 275 | |
| 276 | 276 | ret = dquot_alloc_space_nodirty(inode, nr); |
| 277 | - if (!ret) | |
| 278 | - mark_inode_dirty_sync(inode); | |
| 277 | + if (!ret) { | |
| 278 | + /* | |
| 279 | + * Mark inode fully dirty. Since we are allocating blocks, inode | |
| 280 | + * would become fully dirty soon anyway and it reportedly | |
| 281 | + * reduces inode_lock contention. | |
| 282 | + */ | |
| 283 | + mark_inode_dirty(inode); | |
| 284 | + } | |
| 279 | 285 | return ret; |
| 280 | 286 | } |
| 281 | 287 |