On 18/06/2014 06:04, Ming Lei wrote: > For virtio-blk, I don't think it is always better to take more queues, and > we need to leverage below things in host side: > > - host storage top performance, generally it reaches that with more > than 1 jobs with libaio(suppose it is N, so basically we can use N > iothread per device in qemu to try to get top performance) > > - iothreads' loading(if iothreads are at full loading, increasing > queues doesn't help at all) > > In my test, I only use the current per-dev iothread(x-dataplane) > in qemu to handle 2 vqs' notification and precess all I/O from > the 2 vqs, and looks it can improve IOPS by ~30%. > > For virtio-scsi, the current usage doesn't make full use of blk-mq's > advantage too because only one vq is active at the same time, so I > guess the multi vqs' benefit won't be very much and I'd like to post > patches to support that first, then provide test data with > more queues(8, 16). Hi Ming Lei, would you like to repost these patches now that MQ support is in the kernel? Also, I changed my mind about moving linux-aio to AioContext. I now think it's a good idea, because it limits the number of io_getevents syscalls. O:-) So I would be happy to review your patches for that as well. Paolo _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
