Re: [Qemu-devel] Lock contention in QEMU

2016-12-19 Thread Weiwei Jia
Got it. Thank you very much. Best, Weiwei Jia On Mon, Dec 19, 2016 at 5:58 AM, Stefan Hajnoczi wrote: > On Fri, Dec 16, 2016 at 04:42:54PM -0500, Weiwei Jia wrote: >> Has x-data-plane been used (or accepted) widely in systems. I have >> this concern since if it hasn't been

Re: [Qemu-devel] Lock contention in QEMU

2016-12-19 Thread Stefan Hajnoczi
On Fri, Dec 16, 2016 at 04:42:54PM -0500, Weiwei Jia wrote: > Has x-data-plane been used (or accepted) widely in systems. I have > this concern since if it hasn't been widely accepted, it may > have/cause some problems we don't know. Do you know some hidden > problems which may caused by QEMU

Re: [Qemu-devel] Lock contention in QEMU

2016-12-16 Thread Weiwei Jia
Hi Stefan, I still have another concern like following. Has x-data-plane been used (or accepted) widely in systems. I have this concern since if it hasn't been widely accepted, it may have/cause some problems we don't know. Do you know some hidden problems which may caused by QEMU x-data-plane

Re: [Qemu-devel] Lock contention in QEMU

2016-12-16 Thread Weiwei Jia
On Fri, Dec 16, 2016 at 4:48 AM, Stefan Hajnoczi wrote: > On Thu, Dec 15, 2016 at 11:04:23AM -0500, Weiwei Jia wrote: >> On Thu, Dec 15, 2016 at 3:06 AM, Stefan Hajnoczi wrote: >> > On Thu, Dec 15, 2016 at 12:17:09AM -0500, Weiwei Jia wrote: >> >> BTW, do

Re: [Qemu-devel] Lock contention in QEMU

2016-12-16 Thread Stefan Hajnoczi
On Thu, Dec 15, 2016 at 11:04:23AM -0500, Weiwei Jia wrote: > On Thu, Dec 15, 2016 at 3:06 AM, Stefan Hajnoczi wrote: > > On Thu, Dec 15, 2016 at 12:17:09AM -0500, Weiwei Jia wrote: > >> BTW, do we have an example to show users how to config following > >> virtio-blk dataplane

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Weiwei Jia
I will try it later on. Thank you. Best, Weiwei Jia On Thu, Dec 15, 2016 at 7:13 AM, Paolo Bonzini wrote: > > > On 15/12/2016 09:04, Stefan Hajnoczi wrote: >>> Does this feature only work for VirtIO? Does it work for SCSI or IDE? >> This only works for virtio-blk and

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Weiwei Jia
On Thu, Dec 15, 2016 at 3:06 AM, Stefan Hajnoczi wrote: > On Thu, Dec 15, 2016 at 12:17:09AM -0500, Weiwei Jia wrote: >> BTW, do we have an example to show users how to config following >> virtio-blk dataplane commands into XML configuration file? >> >> qemu -object

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Weiwei Jia
On Thu, Dec 15, 2016 at 3:04 AM, Stefan Hajnoczi wrote: > On Wed, Dec 14, 2016 at 08:06:10PM -0500, Weiwei Jia wrote: >> Hi Stefan, >> >> Thanks for your reply. Please see the inline replies. >> >> On Wed, Dec 14, 2016 at 2:31 PM, Stefan Hajnoczi wrote: >>

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Paolo Bonzini
On 15/12/2016 09:04, Stefan Hajnoczi wrote: >> Does this feature only work for VirtIO? Does it work for SCSI or IDE? > This only works for virtio-blk and virtio-scsi. The virtio-scsi > dataplane support is more recent and I don't remember if it is complete. > I've CCed Fam and Paolo who worked

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Stefan Hajnoczi
On Thu, Dec 15, 2016 at 12:17:09AM -0500, Weiwei Jia wrote: > BTW, do we have an example to show users how to config following > virtio-blk dataplane commands into XML configuration file? > > qemu -object iothread,id=iothread0 \ > -drive if=none,id=drive0,file=test.img,format=raw,cache=none

Re: [Qemu-devel] Lock contention in QEMU

2016-12-15 Thread Stefan Hajnoczi
On Wed, Dec 14, 2016 at 08:06:10PM -0500, Weiwei Jia wrote: > Hi Stefan, > > Thanks for your reply. Please see the inline replies. > > On Wed, Dec 14, 2016 at 2:31 PM, Stefan Hajnoczi wrote: > > On Wed, Dec 14, 2016 at 12:58:11AM -0500, Weiwei Jia wrote: > >> I find the

Re: [Qemu-devel] Lock contention in QEMU

2016-12-14 Thread Weiwei Jia
BTW, do we have an example to show users how to config following virtio-blk dataplane commands into XML configuration file? qemu -object iothread,id=iothread0 \ -drive if=none,id=drive0,file=test.img,format=raw,cache=none \ -device virtio-blk-pci,iothread=iothread0,drive=drive0

Re: [Qemu-devel] Lock contention in QEMU

2016-12-14 Thread Weiwei Jia
Hi Stefan, Thanks for your reply. Please see the inline replies. On Wed, Dec 14, 2016 at 2:31 PM, Stefan Hajnoczi wrote: > On Wed, Dec 14, 2016 at 12:58:11AM -0500, Weiwei Jia wrote: >> I find the timeslice of vCPU thread in QEMU/KVM is unstable when there >> are lots of

Re: [Qemu-devel] Lock contention in QEMU

2016-12-14 Thread Stefan Hajnoczi
On Wed, Dec 14, 2016 at 12:58:11AM -0500, Weiwei Jia wrote: > I find the timeslice of vCPU thread in QEMU/KVM is unstable when there > are lots of read requests (for example, read 4KB each time (8GB in > total) from one file) from Guest OS. I also find that this phenomenon > may be caused by lock

[Qemu-devel] Lock contention in QEMU

2016-12-13 Thread Weiwei Jia
Hi Stefan, I find the timeslice of vCPU thread in QEMU/KVM is unstable when there are lots of read requests (for example, read 4KB each time (8GB in total) from one file) from Guest OS. I also find that this phenomenon may be caused by lock contention in QEMU layer. I find this problem under