From: Ingo Molnar <mingo@elte.hu>
To: kus Kusche Klaus <kus@keba.com>
Cc: linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org,
B.Zolnierkiewicz@elka.pw.edu.pl,
Florian Schmidt <mista.tapas@gmx.net>
Subject: Re: 2.6.11, IDE: Strange scheduling behaviour: high-pri RT process not scheduled?
Date: Thu, 31 Mar 2005 13:35:27 +0200 [thread overview]
Message-ID: <20050331113526.GB27731@elte.hu> (raw)
In-Reply-To: <AAD6DA242BC63C488511C611BD51F3673231C2@MAILIT.keba.co.at>
* kus Kusche Klaus <kus@keba.com> wrote:
> I've written a small test program which enables periodic RTC
> interrupts at 8192 Hz and then goes into a loop reading /dev/rtc and
> collecting timing statistics (using the rdtscl macro).
getting /dev/rtc handling right for latency measurement is ... tricky.
The method i'm using under PREEMPT_RT is:
chrt -f 84 -p `pidof 'IRQ 0'`
chrt -f 95 -p `pidof 'IRQ 8'`
./rtc_wakeup -f 1024 -t 100000
you can get rtc_wakeup from:
http://www.affenbande.org/~tapas/wiki/index.php?rtc_wakeup
written by Florian Schmidt.
do you see high latencies even with rtc_wakeup?
Ingo
next prev parent reply other threads:[~2005-03-31 11:35 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2005-03-30 11:52 2.6.11, IDE: Strange scheduling behaviour: high-pri RT process not scheduled? kus Kusche Klaus
2005-03-30 12:06 ` Bartlomiej Zolnierkiewicz
2005-03-30 14:41 ` Mark Hahn
2005-03-30 20:37 ` Lee Revell
2005-03-31 11:35 ` Ingo Molnar [this message]
-- strict thread matches above, loose matches on Subject: below --
2005-03-30 12:21 kus Kusche Klaus
2005-03-31 11:05 kus Kusche Klaus
2005-03-31 15:19 kus Kusche Klaus
2005-03-31 15:22 ` Ingo Molnar
2005-04-01 9:07 kus Kusche Klaus
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