That is pretty terrible performance. If you could try digging around a bit with perf, blktrace, etc. that'd be much appreciated - otherwise I'll see if I can come up with some way of reproducing it as soon as I have time. I haven't done a lot of performance testing on upstream kernels, unfortunately. On Wed, May 23, 2012 at 9:14 PM, Qinling <mail.qinling@xxxxxxxxxx> wrote: > Hi Kent, > > > > I have tested bcache on my platform, but the result is not good. I think > maybe the wrong config caused it. Would you pls help me to check the config, > or give me some advice for bcache performance testing? > > > > My SSD card is a PCIe SSD card (about 120,000 IOPS), and I used 10GB. > > > > I have download the code from > git://evilpiepirate.org/~kent/linux-bcache.git. > > The commands creating bcache is below: > > make-bcache –B /dev/sdb8 > > make-bcache –C –w4k –b1M –writeback /dev/hioa5 > > > > I use FIO to test the seq./random IO performance, and the result is below: > > write read randwrite randread > > bcache 10809 KB/s 164502.5 KB/s 2713 KB/s 29640 KB/s > > cache_hit_rate 80 79 94 > 92 > > > > > > And the basic test result is: > > Write read randwrite randread > > HDD 81211.6 KB/s 172242 KB/s 2606 KB/s 1855 KB/s > > SSD 250948.2 KB/s 813855 KB/s 238892.7 KB/s 657319.5 KB/s > > -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
