On Wed, Feb 20, 2013 at 12:34:12AM +0800, Daniel J Blueman wrote:
> Hi Paul,
>
> On some of our larger servers with many hundreds of cores and when
> under high duress, we can see scheduler RCU stall warnings [1], so
> find we have to increase the hardcoded RCU_STALL_RAT_DELAY up from 2
> and RCU_JIFFIES_TILL_FORCE_QS up from 3.
>
> Is there a more sustainable way to account for this to avoid it
> being hard-coded, such as making it and dependent timeouts a
> fraction of CONFIG_RCU_CPU_STALL_TIMEOUT?
>
> On the other hand, perhaps this is just caused by clock jitter (eg
> due to distance from a contended clock source)? So increasing these
> a bit may just be adequate in general...
Hmmm... What version of the kernel are you running?
Thanx, Paul
> Many thanks,
> Daniel
>
> --- [1]
>
> [ 3939.010085] INFO: rcu_sched detected stalls on CPUs/tasks: {}
> (detected by 1, t=29662 jiffies, g=3053, c=3052, q=598)
> [ 3939.020008] INFO: Stall ended before state dump start
> --
> Daniel J Blueman
> Principal Software Engineer, Numascale Asia
>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
