[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6
From: |
Ming Lei |
Subject: |
Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2 |
Date: |
Fri, 27 Jun 2014 09:15:59 +0800 |
On Thu, Jun 26, 2014 at 11:57 PM, Paolo Bonzini <address@hidden> wrote:
> This is indeed a difference between the ioq-based and block-based backends.
> ioq could submit more than one request with the same io_submit system call.
>
Yes, I have been thinking that is advantage of qemu virtio dataplane, but
it isn't any longer, and qemu dataplane has not any performance
advantage compared with lkvm now.
> We can implement (advisory) calls like bdrv_plug/bdrv_unplug in order to
> restore the previous levels of performance.
Yes, that is also what I am thinking, or interfaces like bdrv_queue_io()
and bdrv_submit_io(), which may match with aio interfaces.
>
> Note that some fallout of the conversion was expected. Dataplane told us
> experimentally what level of performance could be reached, but was a dead
> end in terms of functionality. Now Stefan added a whole lot of
> functionality to dataplane (accounting, throttling, file formats and
> protocols, thread-pool based I/O, etc.) and we need to bring back any
> performance we lost in the process.
These features are very good, but looks the conversion is a bit early, :-(
>
> Out of curiosity, how does aio=threads (after the patch) fare in comparison
> to aio=native (before the patch)?
Looks no obvious difference.
Thanks,
--
Ming Lei
- [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Ming Lei, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Paolo Bonzini, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Ming Lei, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Paolo Bonzini, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Ming Lei, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Paolo Bonzini, 2014/06/26
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2,
Ming Lei <=
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Paolo Bonzini, 2014/06/27
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Kevin Wolf, 2014/06/27
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Paolo Bonzini, 2014/06/27
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Ming Lei, 2014/06/27
- Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Ming Lei, 2014/06/27
Re: [Qemu-devel] [regression] dataplane: throughout -40% by commit 580b6b2aa2, Stefan Hajnoczi, 2014/06/27