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From: Avi Kivity <avi@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: Kevin Wolf <kwolf@redhat.com>,
	Jan Kiszka <jan.kiszka@siemens.com>,
	Anthony Liguori <aliguori@us.ibm.com>,
	Michael Tokarev <mjt@tls.msk.ru>,
	qemu-devel <qemu-devel@nongnu.org>
Subject: Re: [Qemu-devel] coroutine-ucontext broken for x86-32
Date: Wed, 09 May 2012 17:37:40 +0300	[thread overview]
Message-ID: <4FAA8134.9060701@redhat.com> (raw)
In-Reply-To: <CAFEAcA-RK+_RAYZP9qYvhyuzF_o2OF=q7kYsqPOwtKLknPqPeQ@mail.gmail.com>

On 05/09/2012 02:15 PM, Peter Maydell wrote:
> I think it's becoming increasingly obvious that the setcontext/getcontext
> code path is not very well used and prone to nasty libc bugs. Trying
> to implement coroutines in C is just a really bad idea and I think
> we should be trying to reduce our use of them if we possibly can,
> presumably by switching to actually using threads where we really
> need the parallelism.
>

I happen to like coroutines, but if we switch to threads, we should
ensure that we eliminate the extra context switch if the layer below
(usually posix-aio-compat) also uses threads.  That leaves a theoretical
regression with qcow2-on-native-aio, but that's a fairly rare use case.

-- 
error compiling committee.c: too many arguments to function

  parent reply	other threads:[~2012-05-09 14:37 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-05-08 19:35 [Qemu-devel] coroutine-ucontext broken for x86-32 Jan Kiszka
2012-05-09  7:32 ` Michael Tokarev
2012-05-09 11:12   ` Jan Kiszka
2012-05-09 10:11 ` Kevin Wolf
2012-05-09 10:55   ` Jan Kiszka
2012-05-09 11:15   ` Peter Maydell
2012-05-09 11:38     ` Jan Kiszka
2012-05-09 17:17       ` Anthony Liguori
2012-05-09 17:25         ` Jan Kiszka
2012-05-09 17:31           ` Anthony Liguori
2012-05-09 18:21             ` Jan Kiszka
2012-05-09 14:37     ` Avi Kivity [this message]
2012-05-09 18:05 ` Michael Tokarev

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