From: Jon Masters <jonathan@jonmasters.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jon Masters <jcm@jonmasters.org>,
mingo@elte.hu, tglx@linutronix.de, williams@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [PULL] hardware latency detector
Date: Thu, 18 Jun 2009 21:32:20 -0400 [thread overview]
Message-ID: <1245375140.14766.25.camel@localhost.localdomain> (raw)
In-Reply-To: <alpine.LFD.2.01.0906181824540.16802@localhost.localdomain>
On Thu, 2009-06-18 at 18:25 -0700, Linus Torvalds wrote:
>
> On Thu, 18 Jun 2009, Jon Masters wrote:
> >
> > Please pull "hwlat", the hardware latency detector for 2.6.31.
>
> I really want to know more before I pull.
Ok.
> Has this been in -next?
No, it hasn't. But it has been tested quite extensively by a number of
people and is currently in the -rt tree.
> Discussed on lkml?
Yes. I posted an RFC patch back when it was called the SMI detector,
then a patch last week with the new generic name of hardware latency
detector (at Ingo's suggestion of renaming).
> How does it work?
It started as an SMI detector. Basically, when this module is loaded and
enabled, it will grab all CPUs in periodic calls to stop_machine and sit
in a configurable loop, looking for unexplainable latencies. Doing it
this way allows us to look for something stealing the CPU from Linux
without the kernel knowing - we report the statistics via debugfs.
Hope that helps! Thanks Linus!
Jon.
next prev parent reply other threads:[~2009-06-19 1:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-19 1:21 [PULL] hardware latency detector Jon Masters
2009-06-19 1:25 ` Linus Torvalds
2009-06-19 1:32 ` Jon Masters [this message]
-- strict thread matches above, loose matches on Subject: below --
2009-06-19 1:16 Jon Masters
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=1245375140.14766.25.camel@localhost.localdomain \
--to=jonathan@jonmasters.org \
--cc=jcm@jonmasters.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mingo@elte.hu \
--cc=tglx@linutronix.de \
--cc=torvalds@linux-foundation.org \
--cc=williams@redhat.com \
/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