Re: WARNING: at kernel/rcutree.c:1558 rcu_do_batch+0x386/0x3a0(),during CPU hotplug
From: Srivatsa S. Bhat
Date: Fri Sep 14 2012 - 08:35:09 EST
On 09/14/2012 05:55 PM, Peter Zijlstra wrote:
> On Fri, 2012-09-14 at 17:48 +0530, Srivatsa S. Bhat wrote:
>> #! /bin/bash
>> NUMBER_OF_CPUS=`ls -d /sys/devices/system/cpu/cpu[0-9]* | wc -l`
> apply the above
>> cd /sys/devices/system/cpu
> skip this, so running the script doesn't change PWD
>> while [ 1 ]
> while :;
>> for ((i=1; i < NUMBER_OF_CPUS; i++))
>> sleep 1;
> Also play with shorter sleeps like: sleep .1, I've found that higher
> hotplug rate triggers some races faster.
>> state=`cat cpu$i/online`
>> if [ $state -eq 0 ]
>> echo 1 > cpu$i/online
>> echo 0 > cpu$i/online
> echo $((state^1)) > $CPUPATH/cpu$i/online
Thanks a lot Peter for your suggestions!
Fengguang, like I had mentioned some time before, somebody had pointed
me to a hotplug test-suite that I believe is being used in LTP.
I have a copy of that suite, which I have attached with this mail.
I have never actually used it seriously before (because I could trigger
bugs with my simple script!), so I don't exactly know what state it is
Srivatsa S. Bhat