From: Peter Zijlstra <peterz@infradead.org>
To: sen wang <wangsen.linux@gmail.com>
Cc: mingo@elte.hu, akpm@linux-foundation.org, kernel@kolivas.org,
npiggin@suse.de, arjan@infradead.org,
linux-arm-kernel@lists.arm.linux.org.uk,
linux-kernel@vger.kernel.org
Subject: Re: report a bug about sched_rt
Date: Fri, 24 Jul 2009 15:14:50 +0200 [thread overview]
Message-ID: <1248441290.6987.52.camel@twins> (raw)
In-Reply-To: <454c71700907240604h4673f117j8ed58b9f2ee54798@mail.gmail.com>
Don't top post -- again!
On Fri, 2009-07-24 at 21:04 +0800, sen wang wrote:
> Linux is used in many fieldes. SCHED_OTHER tasks is important to
> embedded system.
Irrelevant.
> if there is a running state task（a realtime task）, how can we
> shcedule the idle task up?
Because it ran out of bandwidth.
> It is ridiculous！
>
> since the throttle has a bug, why not fix it?
It doesn't have a bug, therefore I won't fix it.
The throttle limits the RT tasks to a bandwidth w of u/p.
Since real-time scheduling is about determinism a maximum bandwidth
larger than the minimum bandwidth specified by w is useless since it
cannot be relied upon.
Therefore we don't run RT tasks beyond their bandwidth limit.
Go read up on scheduling theory.
Now you might want a bandwidth of 100% for your RT application (not
something I can recommend for the overall health of your machine) in
which case you're free to change this setting:
echo -1 > /proc/sys/kernel/sched_rt_runtime_us
Should do that for you. Also read:
Documentation/scheduler/sched-rt-group.txt
next prev parent reply other threads:[~2009-07-24 13:13 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-24 10:57 report a bug about sched_rt sen wang
2009-07-24 12:14 ` Peter Zijlstra
2009-07-24 13:04 ` sen wang
2009-07-24 13:14 ` Peter Zijlstra [this message]
2009-07-24 13:26 ` sen wang
2009-07-24 13:33 ` Peter Zijlstra
2009-07-24 13:44 ` sen wang
2009-07-24 13:54 ` Peter Zijlstra
2009-07-24 14:04 ` sen wang
2009-07-24 14:48 ` Peter Zijlstra
2009-07-24 14:53 ` sen wang
2009-07-24 15:07 ` sen wang
2009-07-24 15:24 ` Peter Zijlstra
2009-07-24 15:43 ` sen wang
2009-07-24 15:34 ` Thomas Gleixner
2009-07-25 11:12 ` Raistlin
2009-07-24 14:24 ` sen wang
2009-07-24 14:48 ` Peter Zijlstra
2009-07-24 15:02 ` sen wang
2009-07-24 15:40 ` Jamie Lokier
2009-07-24 16:01 ` Peter Zijlstra
2009-07-24 23:30 ` Jamie Lokier
2009-07-25 5:22 ` Bill Gatliff
2009-07-25 22:48 ` Jamie Lokier
2009-07-26 2:44 ` Bill Gatliff
2009-07-26 19:03 ` Jamie Lokier
2009-07-27 10:45 ` Peter Zijlstra
2009-07-27 13:35 ` Bill Gatliff
2009-07-25 12:33 ` Raistlin
2009-07-25 14:58 ` Tommaso Cucinotta
2009-07-25 12:19 ` Raistlin
2009-07-25 22:54 ` Jamie Lokier
2009-07-25 23:24 ` Tommaso Cucinotta
2009-07-25 11:10 ` Raistlin
[not found] ` <454c71700907250429i1c77658bt6d65b02f08a29f4a@mail.gmail.com>
2009-07-25 23:01 ` Jamie Lokier
2009-07-24 14:28 ` Arjan van de Ven
2009-07-26 3:55 ` sen wang
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