From: Peter Zijlstra <peterz@infradead.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Jean Delvare <khali@linux-fr.org>,
Thomas Gleixner <tglx@linutronix.de>,
Leon Woestenberg <leon.woestenberg@gmail.com>,
Mark Brown <broonie@opensource.wolfsonmicro.com>,
Sven-Thorsten Dietrich <sven@thebigcorporation.com>,
linux-i2c@vger.kernel.org,
rt-users <linux-rt-users@vger.kernel.org>,
"Ben Dooks (embedded platforms)" <ben-linux@fluff.org>,
LKML <linux-kernel@vger.kernel.org>
Subject: Re: yield() in i2c non-happy paths hits BUG under -rt patch
Date: Thu, 19 Nov 2009 14:06:54 +0100 [thread overview]
Message-ID: <1258636014.4372.328.camel@twins> (raw)
In-Reply-To: <20091119125906.6ad00edd@lxorguk.ukuu.org.uk>
On Thu, 2009-11-19 at 12:59 +0000, Alan Cox wrote:
> > Well, I guess only people monitoring system latency would notice, as
> > this is the only thing yield() was supposed to help with in the first
> > place.
>
> if (need_resched())
> schedule();
aka.
cond_resched();
> will make non-rt tasks act politely at the right moments. RT tasks will
> likely immediately get to take the CPU again depending upon the
> scheduling parameters in use.
Right, FIFO will simply NOP it, since if it was the highest running
task, it will still be. RR could possibly run out of its slice and
schedule to another RR of the same prio.
next prev parent reply other threads:[~2009-11-19 13:05 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <c384c5ea0911071101u7415d37o2611c542e5fae309@mail.gmail.com>
[not found] ` <20091107210147.3e754278@hyperion.delvare>
[not found] ` <4AF7148C.9090706@thebigcorporation.com>
[not found] ` <20091112211255.09cd884a@hyperion.delvare>
2009-11-13 22:03 ` yield() in i2c non-happy paths hits BUG under -rt patch Thomas Gleixner
2009-11-14 18:02 ` Jean Delvare
2009-11-16 15:56 ` Mark Brown
2009-11-18 0:50 ` Leon Woestenberg
2009-11-18 1:05 ` Alan Cox
2009-11-18 16:28 ` Leon Woestenberg
2009-11-18 16:52 ` Jean Delvare
2009-11-18 20:36 ` Thomas Gleixner
2009-11-19 12:05 ` Jean Delvare
2009-11-19 12:59 ` Alan Cox
2009-11-19 13:06 ` Peter Zijlstra [this message]
2009-11-19 14:00 ` Jean Delvare
2009-11-19 14:15 ` Peter Zijlstra
2009-11-19 13:11 ` Thomas Gleixner
2009-11-19 13:21 ` Peter Zijlstra
2009-11-19 13:22 ` Thomas Gleixner
2009-11-19 13:18 ` Peter Zijlstra
2009-11-18 20:46 ` [PATCH] cleanup sched_yield (sys)call nesting Sven-Thorsten Dietrich
2009-11-18 20:56 ` Thomas Gleixner
2009-11-18 21:04 ` Sven-Thorsten Dietrich
2009-11-18 21:34 ` Thomas Gleixner
2009-11-19 4:48 ` Sven-Thorsten Dietrich
2009-11-19 10:36 ` Thomas Gleixner
2009-11-19 3:20 ` Ingo Molnar
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