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Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Lin
From: |
Peter Maydell |
Subject: |
Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host |
Date: |
Wed, 9 May 2012 21:46:28 +0100 |
On 9 May 2012 21:11, Jan Kiszka <address@hidden> wrote:
> OK. Then what about sigaltstack (once fixed)? Is it also slower? If not,
> can we converge over it?
sigaltstack is going to be significantly faster than the gthread
implementation (about the same speed as ucontext for coroutine
switch, a bit slower for coroutine creation).
It suffers from the same problem of being a code path which nobody
has seriously stress tested, though. And it does at least one thing
which is "not permitted by the standards but works anyway".
> I would really hate staying with this time bomb
> of broken RT signals unless someone tells me we will kick out all these
> coroutines rather sooner than later.
I think that regardless of the long term choice it would be
a pretty risky decision to switch coroutine implementation
this close to release when we have the option of just using
a different signal that avoids the bug.
Longer term (ie post 1.1) I'm strongly in favour of kicking
out coroutines, because I think there clearly is no single
solid portable implementation possible. C just isn't designed
to allow them; better not to try to swim against the current.
-- PMM
- [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Jan Kiszka, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Michael Tokarev, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Jan Kiszka, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Anthony Liguori, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Jan Kiszka, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Anthony Liguori, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Jan Kiszka, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host,
Peter Maydell <=
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Anthony Liguori, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Peter Maydell, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Anthony Liguori, 2012/05/09
- Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Anthony Liguori, 2012/05/09
Re: [Qemu-devel] [PATCH 1.1] coroutine: Avoid ucontext usage on i386 Linux host, Michael Tokarev, 2012/05/09