From: Mike Galbraith <umgwanakikbuti@gmail.com>
To: jimmie.davis@l-3com.com
Cc: artem_fetishev@epam.com, peterz@infradead.org,
kosaki.motohiro@jp.fujitsu.com, linux-kernel@vger.kernel.org
Subject: RE: Bug 71331 - mlock yields processor to lower priority process
Date: Fri, 21 Mar 2014 14:14:40 +0100 [thread overview]
Message-ID: <1395407680.6030.81.camel@marge.simpson.net> (raw)
In-Reply-To: <FFF95760268D324AB6DD9426E83C8DF70B2E5870@ARLEXCHMBX01.lst.link.l-3com.com>
On Fri, 2014-03-21 at 12:18 +0000, jimmie.davis@l-3com.com wrote:
> As the submitter of the bug, let me give you my perspective.
> SCHED_FIFO means run my task until it blocks or a higher priority task
> pre-empts it. Period.
It blocked.
>
> mlock() doesn't block. check the man page.
>
I don't see that specified.
(or how it could be, but what do I know, IANIPL)
> Any other way and you are not able to use priority based scheduling.
Sure you can, allocate and lock down resources before entering critical
sections.
If you think donning a SCHED_FIFO super-suit should make your task
unstoppable, you're gonna be very disappointed. Fact is if your
Juggernaut bumps ever so gently into a contended sleeping variety lock
(and in the rt kernel that means nearly every lock), it will block.
-Mike
next prev parent reply other threads:[~2014-03-21 13:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-21 20:02 Artem Fetishev
2014-03-21 9:23 ` Mike Galbraith
2014-03-21 12:18 ` jimmie.davis
2014-03-21 13:14 ` Mike Galbraith [this message]
2014-03-21 14:34 ` jimmie.davis
2014-03-21 14:54 ` Motohiro Kosaki
2014-03-21 13:35 ` Oliver Neukum
2014-03-21 14:01 ` jimmie.davis
2014-03-21 14:41 ` Mike Galbraith
2014-03-21 14:50 ` jimmie.davis
2014-03-27 0:39 ` Andy Lutomirski
2014-03-27 4:20 ` jimmie.davis
2014-03-27 5:35 ` Mike Galbraith
2014-03-27 6:02 ` Robert Hancock
2014-03-27 11:37 ` jimmie.davis
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