On Tue, Jan 2, 2018 at 6:34 AM, <tang.junhui@xxxxxxxxxx> wrote: > From: Tang Junhui <tang.junhui@xxxxxxxxxx> > >>On 01/02/2018 12:53 AM, tang.junhui@xxxxxxxxxx wrote: >>> If no front-end I/O coming, would this cause write-back IOs one by one >>> (one write-back IO issued must after the completion of the previous IO)? >>> though with zero delay time, is the write-back performance still good? >> >>Yes-- this speeds up writeback during idle from 4k/sec to about 10MB/sec >>on my slow 5400RPM disk. (It writes back at about 20MB/sec with deep >>queues in the same scenario). So in this case it's about 2500x faster >>than current idle writeback, but half as fast as writeback with full >>device utilization. >> >>With only one I/O outstanding at a time, if front-end I/O starts latency >>for the first request is still good. >> > > OK, LGTM. Excellent, thank you! > Reviewed-by: Tang Junhui <tang.junhui@xxxxxxxxxx> Added to bcache-for-next. Mike > > Thanks, > Tang Junhui > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html
