Re: [patch] Real-Time Preemption, -RT-2.6.12-rc6-V0.7.48-00

From: William Weston
Date: Thu Jun 23 2005 - 20:52:57 EST


On Thu, 23 Jun 2005, William Weston wrote:

> Running -50-17 on the Xeon/HT box, now with the ICH5 USB controller
> disabled in BIOS.
>
> The strangely regular ~200us idle jumps for both CPUs went away. Now I'm
> seeing one CPU at a time disappear (often completely absent) in the
> traces, with a the maximum wakeup generally hitting between 150us and
> 300us. While compiling a kernel and running vlc (which would skip frames
> like mad, even with RR scheduling) I was able to get one trace of 2556us.
>
> There's also BUG warnings for update_out_trace(). I'm not quite sure if
> the trace behavior I'm seeing is related to this bug, but judging by the
> behavior of vlc, I wouldn't bet on it.
>
> Since the 2556us trace is quite large all the info is posted at:
>
> http://sysex.net/testing/2.6.12-RT-V0.7.50-17/xeonht/

OK... Running on -50-17 with all RT debug except CONFIG_WAKEUP_TIMING and
CONFIG_LATENCY_TIMING disabled. Max wakeup latency is 59us now, with a
couple erroneous values of 2533412143us. VLC performance (streaming from
a multicast UDP source) was great with one instance of burnP6 running.
Running a second burnP6 along with VLC locks up the box (reproduceable) in
about a minute. Running two or more instances of burnP6 without VLC does
not result in any odd behavior or noticeably impact GUI performance. I
rebuilt with CONFIG_DETECT_SOFTLOCKUP enabled, but couldn't catch a trace.

FWIW, --ww
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