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From: Jan Kiszka <jan.kiszka@web.de>
To: Anthony Liguori <aliguori@us.ibm.com>
Cc: Amit Shah <amit.shah@redhat.com>,
	Paolo Bonzini <pbonzini@redhat.com>,
	qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 00/19] chardev flow control
Date: Sun, 24 Mar 2013 19:02:13 +0100	[thread overview]
Message-ID: <514F3FA5.2050903@web.de> (raw)
In-Reply-To: <1361224096-21075-1-git-send-email-aliguori@us.ibm.com>

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On 2013-02-18 22:47, Anthony Liguori wrote:
> This series implements an idea from Paolo to introduce flow control
> in the char layer by converting all char backends to use GIOChannels
> internally.  Then we can just use the existing IO watch support in glib
> to implement flow control.
> 
> This is based on a rebased version of an old series of mine plus a
> number of improvements from Amit Shah.

There is a problem with these changes, maybe just a small bug but I do
not see a simple solution yet:

If an input channel signals readiness but the frontend has no space
(can_read returns 0), the main loop will start busy-waiting, causing
100% CPU load.

It's trivial to reproduce: qemu-system-x86_64 -serial stdio -S, and then
hit a key twice on that console.

Jan



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      parent reply	other threads:[~2013-03-24 18:02 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <1361224096-21075-1-git-send-email-aliguori@us.ibm.com>
     [not found] ` <1361224096-21075-17-git-send-email-aliguori@us.ibm.com>
2013-03-05 17:23   ` [Qemu-devel] [PATCH 16/19] qemu-char: move msmouse registeration to msmouse.c Amit Shah
2013-03-24 18:02 ` Jan Kiszka [this message]

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