[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [6391] Fix nographic mode and VNC
From: |
Paul Brook |
Subject: |
Re: [Qemu-devel] [6391] Fix nographic mode and VNC |
Date: |
Fri, 23 Jan 2009 18:59:01 +0000 |
User-agent: |
KMail/1.9.9 |
> > > The third possibility is to have the select() run in a separate thread
> > > from the TCG cpu_exec() loop. cpu_exec() would do an atomic read of
> > > 'event_pending' and the IO thread would do an atomic write of
> > > 'event_pending' whenever select() returned a writable file descriptor.
> >
> > This suffers from the same problem described above. You need to
> > force the main execution thread to break out of the translated
> > loop. In practice this probably means sending a signal to the main
> > thread. You could check event_pending at the start of every TB, but
> > that's likely to incur a fairly big performance hit.
>
> What would the signal handler do ? siglongjmp out of the translated
> loop ? Surely the timer implementation doesn't do that right now.
The same as the current one does. Call cpu_interrupt to unlink the TB and
cause execution to fall back to cpu_exec sometime in the near future.
cpu_interrupt is not threadsafe[1] so has to be called from the main execution
thread.
[1] TB [un-]chaining involves direct patching of the translated code. Most SMP
systems do not have a coherent icache.
Paul
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, (continued)
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Samuel Thibault, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Blue Swirl, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Samuel Thibault, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Blue Swirl, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Anthony Liguori, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Paul Brook, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Anthony Liguori, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Paul Brook, 2009/01/21
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Ian Jackson, 2009/01/22
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC,
Paul Brook <=
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Anthony Liguori, 2009/01/22
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Paul Brook, 2009/01/23
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Anthony Liguori, 2009/01/23
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Jamie Lokier, 2009/01/25
- Re: [Qemu-devel] [6391] Fix nographic mode and VNC, Paul Brook, 2009/01/25