2012/3/15 Holger Kiehl <Holger.Kiehl@xxxxxx>: > On Wed, 14 Mar 2012, Shaohua Li wrote: > >> Maybe the discard runs slow with small size request in the disk. >> please drop patch "blk: add plug for blkdev_issue_discard" and try again. >> Since >> we can't do merge, the plug just introduces latency. >> > Tried again without the patch applied, but there is only a very small > performance increase (520->600 agains 4000 fps without discard). > > The benchmark creates lots of small files (2 KiB) and deletes them again. > > >> if it doesn't help, please capture a blktrace when you do the benchmark >> and >> send it to me. >> > Ok, I will do this tomorrow. Need some sleep :-) > > Thanks for your work on supporting discard in MD! I tried your benchmark, create 2000k 2k files and delete them and follows a sync. the discard runs pretty fast for both raid 0/1. So can't reproduce the issue. I'm using a fusionio card though. I'm afraid nothing I can do till get you blktrace. Thanks, Shaohua -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
