From: Doug Niehaus <niehaus@ittc.ku.edu>
To: Joerg Roedel <joro@8bytes.org>
Cc: Ted Baker <baker@cs.fsu.edu>,
raj@ece.cmu.edu, jayhawk@soe.ucsc.edu, a.p.zijlstra@chello.nl,
raistlin@linux.it, henrik@austad.us,
linux-kernel@vger.kernel.org, mingo@elte.hu,
billh@gnuppy.monkey.org, linux-rt-users@vger.kernel.org,
fabio@gandalf.sssup.it, anderson@cs.unc.edu, tglx@linutronix.de,
dhaval.giani@gmail.com, cucinotta@sssup.it,
lipari@retis.sssup.it, baker.tlh@comcast.net
Subject: Re: [Fwd: Re: RFC for a new Scheduling policy/class in the Linux-kernel]
Date: Mon, 26 Apr 2010 13:37:03 -0500 [thread overview]
Message-ID: <4BD5DD4F.5080906@ittc.ku.edu> (raw)
In-Reply-To: <20100426182903.GA14542@8bytes.org>
One limitation of SIGSTOP is that the last time I instrumented it in
detail, which admittedly was several years ago, every process you send
the message to has to run long enough to receive the message.
We were in the the position of sending it to fairly large groups of
processes, partly through laziness in code structure, but when I looked
at the time lines I was appalled to see a large number of context
switches for *very* short execution intervals. All were associated with
receiving the SIGSTOP and SIGCONT.
I found a rather painful humor in the fact that we were running
processes in order to keep them from running.
So, a way to change state of a process that does not cost a context
switch has some appeal.
Doug
On 04/26/2010 01:29 PM, Joerg Roedel wrote:
> On Mon, Apr 26, 2010 at 07:56:58AM -0400, Ted Baker wrote:
>
>> I have not seen any more e-mail on this. How is it going? Is there any
>> chance of rolling in some corrections for the SCHED_SPORADIC treatment? In
>> particular, could we have a DO_NOT_RUN priority, that is guaranteed to
>> prevent a task from running at all?
>>
> Sorry for asking a maybe stupid question, but what is this good for and
> what is the benefit over SIGSTOP?
>
> Joerg
>
>
next prev parent reply other threads:[~2010-04-26 18:59 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-26 11:56 [Fwd: Re: RFC for a new Scheduling policy/class in the Linux-kernel] Ted Baker
2010-04-26 11:56 ` Ted Baker
2010-04-26 18:29 ` Joerg Roedel
2010-04-26 18:37 ` Doug Niehaus [this message]
2010-05-03 14:41 ` Peter Zijlstra
2010-05-03 15:54 ` Ted Baker
2010-05-03 16:13 ` Ted Baker
-- strict thread matches above, loose matches on Subject: below --
2009-07-16 19:41 Raj Rajkumar
[not found] <4A5F7254.3020809@ece.cmu.edu>
2009-07-16 19:18 ` James H. Anderson
[not found] ` <4A5F806D.6040701@ece.cmu.edu>
2009-07-16 19:46 ` James H. Anderson
2009-07-16 20:47 ` Raj Rajkumar
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=4BD5DD4F.5080906@ittc.ku.edu \
--to=niehaus@ittc.ku.edu \
--cc=a.p.zijlstra@chello.nl \
--cc=anderson@cs.unc.edu \
--cc=baker.tlh@comcast.net \
--cc=baker@cs.fsu.edu \
--cc=billh@gnuppy.monkey.org \
--cc=cucinotta@sssup.it \
--cc=dhaval.giani@gmail.com \
--cc=fabio@gandalf.sssup.it \
--cc=henrik@austad.us \
--cc=jayhawk@soe.ucsc.edu \
--cc=joro@8bytes.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-rt-users@vger.kernel.org \
--cc=lipari@retis.sssup.it \
--cc=mingo@elte.hu \
--cc=raistlin@linux.it \
--cc=raj@ece.cmu.edu \
--cc=tglx@linutronix.de \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.