Messages in this thread | | | Date | Tue, 15 Oct 2013 09:05:00 +0800 | From | Shaohua Li <> | Subject | [patch 0/4 v2] blk-mq: use percpu_ida to manage tags |
| |
Hi, blk-mq and percpu_ida use similar algorithm to manage tags. The difference is when a cpu can't allocate tags, blk-mq will use ipi to purge remote cpu cache, while percpu-ida directly purges remote cpu cache. In practice, the percpu-ida approach is much faster when we can't allocate enough for percpu cache.
This patch makes blk-mq use percpu_ida to manage tags, this avoids some duplicate code and has better performance as I mentioned. To test the patches, rebase blk-mq tree to latest kernel first.
The v2 patch updated some log descriptions, fixed one issue Kent pointed out and added performance data.
Thanks, Shaohua
| |