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Re: [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_p
From: |
Fam Zheng |
Subject: |
Re: [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_poll abstraction |
Date: |
Fri, 17 Apr 2015 10:02:30 +0800 |
User-agent: |
Mutt/1.5.23 (2014-03-12) |
On Thu, 04/16 14:03, Stefan Hajnoczi wrote:
> On Thu, Apr 16, 2015 at 12:57:29PM +0800, Fam Zheng wrote:
> > v3: Rebase to master for 2.4.
> > Although epoll_pwait1 syscall is still being worked on [1], the QEMU
> > part
> > (if any) will base on this, so let's merge it first.
> >
> > That part is not included in this version because I'm still evaluating
> > by
> > comparing epoll_pwait1 with epoll+timerfd as with current master they
> > seem
> > to be really close.
> >
> > [1]: http://www.spinics.net/lists/linux-api/msg08216.html
> >
> > v2: Emulate nanoseconds precison of timeout with ppoll and timerfd.
> > Their performance is on par with each other, but both much better than
> > qemu.git:
> >
> > syscall high # of fd low # of fd
> > -------------------------------------------------
> > qemu.git(ppoll) 44 96
> > ppoll+epoll 85 101
> > timerfd+epoll 87 109
> >
> > (In high # of fd case, 3 activated but idle virtio-console devices are
> > attached, which will add us hundereds of fds to poll)
>
> Have you rerun benchmarks with this patch series?
Yes, here:
syscall high # of fd low # of fd
(Unit MB/s) (Unit MB/s)
-------------------------------------------------
qemu.git(ppoll) 24 73
ppoll+epoll 49 77
timerfd+epoll 49 82
>
> I wonder how the ppoll-only performance changes. It seems like there
> are now additional copies of <fd, events, revents> information and
> corresponding malloc/realloc/frees.
>
> Stefan
- [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_poll abstraction, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 1/7] poll: Introduce QEMU Poll API, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 3/7] poll: Add epoll implementation for qemu_poll, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 2/7] posix-aio: Use QEMU poll interface, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 4/7] main-loop: Replace qemu_poll_ns with qemu_poll, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 5/7] tests: Add test case for qemu_poll, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 6/7] poll-glib: Support ppoll, Fam Zheng, 2015/04/16
- [Qemu-devel] [PATCH v3 7/7] poll-linux: Add timerfd support, Fam Zheng, 2015/04/16
- Re: [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_poll abstraction, Stefan Hajnoczi, 2015/04/16
- Re: [Qemu-devel] [PATCH v3 0/7] aio: Support epoll by introducing qemu_poll abstraction,
Fam Zheng <=