From: Avi Kivity <avi@qumranet.com>
To: qemu-devel@nongnu.org
Cc: linux-mips@linux-mips.org
Subject: Re: [Qemu-devel] QEMU/MIPS & dyntick kernel
Date: Tue, 02 Oct 2007 22:27:07 +0200 [thread overview]
Message-ID: <4702A99B.7020008@qumranet.com> (raw)
In-Reply-To: <20071002200644.GA19140@hall.aurel32.net>
Aurelien Jarno wrote:
> Hi,
>
> As announced by Ralf Baechle, dyntick is now available on MIPS. I gave a
> try on QEMU/MIPS, and unfortunately it doesn't work correctly.
>
> In some cases the kernel schedules an event very near in the future,
> which means the timer is scheduled a few cycles only from its current
> value. Unfortunately under QEMU, the timer runs too fast compared to the
> speed at which instructions are execution.
Sounds like a kernel bug. Can't there conceivably exist real hardware
(or a real timeout) that exhibits the same timing?
Especially today with variable clock frequencies, I don't see how the
kernel can rely on exact timing.
--
Any sufficiently difficult bug is indistinguishable from a feature.
next prev parent reply other threads:[~2007-10-02 20:27 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-02 20:06 [Qemu-devel] QEMU/MIPS & dyntick kernel Aurelien Jarno
2007-10-02 20:27 ` Avi Kivity [this message]
2007-10-02 20:37 ` Aurelien Jarno
2007-10-02 20:48 ` Alan Cox
2007-10-02 20:57 ` Aurelien Jarno
2007-10-02 22:35 ` Ralf Baechle
2007-10-04 1:59 ` J. Mayer
2007-10-04 16:19 ` Daniel Jacobowitz
2007-10-15 1:23 ` Paul Brook
2007-10-15 8:15 ` Dor Laor
2007-10-15 15:05 ` Thiemo Seufer
2007-10-15 15:58 ` Ralf Baechle
2007-10-15 16:20 ` Thiemo Seufer
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