Re: [Qemu-devel] Performance about x-data-plane

2017-01-16 Thread Weiwei Jia
On Mon, Jan 16, 2017 at 10:00 AM, Karl Rister wrote: > On 01/16/2017 07:15 AM, Stefan Hajnoczi wrote: >> On Tue, Jan 03, 2017 at 12:02:14PM -0500, Weiwei Jia wrote: The expensive part is the virtqueue kick. Recently we tried polling the virtqueue instead of waiting

Re: [Qemu-devel] Performance about x-data-plane

2017-01-16 Thread Weiwei Jia
On Mon, Jan 16, 2017 at 8:15 AM, Stefan Hajnoczi wrote: > On Tue, Jan 03, 2017 at 12:02:14PM -0500, Weiwei Jia wrote: >> > The expensive part is the virtqueue kick. Recently we tried polling the >> > virtqueue instead of waiting for the ioeventfd file descriptor and got >> >

Re: [Qemu-devel] Performance about x-data-plane

2017-01-16 Thread Karl Rister
On 01/16/2017 07:15 AM, Stefan Hajnoczi wrote: > On Tue, Jan 03, 2017 at 12:02:14PM -0500, Weiwei Jia wrote: >>> The expensive part is the virtqueue kick. Recently we tried polling the >>> virtqueue instead of waiting for the ioeventfd file descriptor and got >>> double-digit performance

Re: [Qemu-devel] Performance about x-data-plane

2017-01-16 Thread Stefan Hajnoczi
On Tue, Jan 03, 2017 at 12:02:14PM -0500, Weiwei Jia wrote: > > The expensive part is the virtqueue kick. Recently we tried polling the > > virtqueue instead of waiting for the ioeventfd file descriptor and got > > double-digit performance improvements: > >

Re: [Qemu-devel] Performance about x-data-plane

2017-01-03 Thread Weiwei Jia
Hi Stefan, Thanks for your reply. On Tue, Jan 3, 2017 at 10:50 AM, Stefan Hajnoczi wrote: > On Thu, Dec 22, 2016 at 01:34:47AM -0500, Weiwei Jia wrote: >> With QEMU x-data-plane, I find the performance has not been improved >> very much. Please see following two settings. >

Re: [Qemu-devel] Performance about x-data-plane

2017-01-03 Thread Stefan Hajnoczi
On Thu, Dec 22, 2016 at 01:34:47AM -0500, Weiwei Jia wrote: > With QEMU x-data-plane, I find the performance has not been improved > very much. Please see following two settings. Using IOThreads improves scalability for SMP guests with many disks. It does not improve performance for a single

[Qemu-devel] Performance about x-data-plane

2016-12-21 Thread Weiwei Jia
Hi, With QEMU x-data-plane, I find the performance has not been improved very much. Please see following two settings. Setting 1: I/O thread in host OS (VMM) reads 4KB each time from disk (8GB in total). Pin the I/O thread to pCPU 5 which will serve I/O thread dedicatedly. I find the performance