From: Avi Kivity <avi@qumranet.com>
To: Michael Malone <michael.malone@tait.co.nz>
Cc: kvm mailing list <kvm@vger.kernel.org>
Subject: Re: serial problems cont..
Date: Mon, 01 Sep 2008 12:26:48 +0300 [thread overview]
Message-ID: <48BBB558.6060909@qumranet.com> (raw)
In-Reply-To: <48BB059E.1050600@tait.co.nz>
Michael Malone wrote:
> Hi everyone,
>
> I've written a couple of questions regarding the serial device in
> KVM. After slightly more investigation I think I have found what's
> going awry. Correct me if I'm wrong, but I believe that KVM generates
> an interrupt for every single character it sends through the serial
> port. This throws CPU usage through the roof and I suspect this means
> that the timers aren't being handled correctly and it failed on a
> string of 0's for me due to the timing slips. GNU/Linux and Windows
> don't have anywhere near the processor usage for their serial ports.
> Now, I know nothing of serial programming and don't have any time to
> investigate it too heavily just now, but I have pulled down the source
> and had a look through that, but it looks to be doing the right thing
> (I suppose?). I was mainly wondering how GNU/Linux and windows
> handle serial interrupts or if some of the serial character events
> could be buffered, rather than overload the processor? I guess this
> is a low priority for you, but any help would be greatly appreciated
> (And when I have some more time, I will spend some of it helping to
> develop KVM! Quid pro quo, Clarice...)
>
What version of kvm are you testing? There were some changes to the
serial emulation recently. See for example
02f0b4c0cc26f3a2578d515d96781f5a6258888d in kvm-73.
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2008-09-01 9:26 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-08-31 20:57 serial problems cont Michael Malone
2008-09-01 9:26 ` Avi Kivity [this message]
2008-09-02 1:25 ` Michael Malone
2008-09-02 8:32 ` Avi Kivity
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