[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode |
Date: |
Tue, 15 Nov 2016 10:32:02 +0000 |
User-agent: |
Mutt/1.7.1 (2016-10-04) |
On Mon, Nov 14, 2016 at 09:52:00PM +0100, Paolo Bonzini wrote:
> On 14/11/2016 21:12, Karl Rister wrote:
> > 256 46,929
> > 512 35,627
> > 1,024 46,477
> > 2,000 35,247
> > 2,048 46,322
> > 4,000 46,540
> > 4,096 46,368
> > 8,000 47,054
> > 8,192 46,671
> > 16,000 46,466
> > 16,384 32,504
> > 32,000 20,620
> > 32,768 20,807
>
> Huh, it breaks down exactly when it should start going faster
> (10^9/46000 = ~21000).
Could it be because we're not breaking the polling loop for BHs, new
timers, or aio_notify()?
Once that is fixed polling should achieve maximum performance when
QEMU_AIO_MAX_POLL_NS is at least as long as the duration of a request.
This is logical if there are enough pinned CPUs so the polling thread
can run flat out.
Stefan
signature.asc
Description: PGP signature
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, (continued)
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Stefan Hajnoczi, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Paolo Bonzini, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Stefan Hajnoczi, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Fam Zheng, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Paolo Bonzini, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Stefan Hajnoczi, 2016/11/15
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Karl Rister, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Karl Rister, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Paolo Bonzini, 2016/11/14
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode,
Stefan Hajnoczi <=
- Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Karl Rister, 2016/11/15
Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, no-reply, 2016/11/13
Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Christian Borntraeger, 2016/11/14
Re: [Qemu-devel] [RFC 0/3] aio: experimental virtio-blk polling mode, Christian Borntraeger, 2016/11/14