From: Stanislav Meduna <stano@meduna.org>
Cc: Ashoka K <ashok.vinu@gmail.com>,
linux-embedded@vger.kernel.org, linux-newbie@vger.kernel.org,
Linux ARM Kernel <linux-arm-kernel@lists.infradead.org>,
linux-rt-users@vger.kernel.org
Subject: Re: Need help to measure and tune the latency in Linux RT
Date: Tue, 30 Apr 2013 14:13:07 +0200 [thread overview]
Message-ID: <517FB553.3000001@meduna.org> (raw)
In-Reply-To: <20130430111021.GC31290@titan.lakedaemon.net>
>> This critical thread is at RR priority 50.
Try to put it higher than the irq thread handling your HD hardware.
I've even encountered hardware where I had to put the ATA thread
in the SHED_OTHER domain - see [1] for the thread.
>> I used a HR timer thread with RR pri 55 to wakeup the critical thread
>> every 1 milli sec to do the job.
Which prio is the ksoftirqd running at? The HRTIMER interrupts are
routed through it so it also has to be high enough.
I got burned with this myself [2]
Regards
Stano
[1] http://www.spinics.net/lists/linux-rt-users/msg08711.html
[2] http://www.spinics.net/lists/linux-rt-users/msg08745.html
next prev parent reply other threads:[~2013-04-30 12:13 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-30 8:27 Need help to measure and tune the latency in Linux RT Ashoka K
2013-04-30 11:10 ` Jason Cooper
2013-04-30 12:13 ` Stanislav Meduna [this message]
2013-04-30 13:17 ` Ashoka K
2013-04-30 12:02 ` ddegraff
[not found] ` <CAPo1LyXaqrGW0rqgvtaEJMoR1Y6NrTdVhV4Jb_gAp_N1ggwu0Q@mail.gmail.com>
2013-05-29 6:02 ` Ashoka K
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=517FB553.3000001@meduna.org \
--to=stano@meduna.org \
--cc=ashok.vinu@gmail.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-embedded@vger.kernel.org \
--cc=linux-newbie@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).