Re: [RFC][PATCH v3 6/6] rcu/tree: Use irq_work_queue_remote()

[Peter Zijlstra]

On Thu, Oct 29, 2020 at 09:04:48AM -0700, Paul E. McKenney wrote:
> On Thu, Oct 29, 2020 at 10:10:53AM +0100, Peter Zijlstra wrote:

> > Dang, clearly TREE01 didn't actually hit any of this code :/ Is there
> > another test I should be running?
> 
> TREE01 is fine, but you have to tell rcutorture to actually generate an
> RCU CPU stall warning.  Like this for a 25-second stall with interrupts
> disabled:
> 
> tools/testing/selftests/rcutorture/bin/kvm.sh --allcpus --duration 3 --configs "10*TREE04" --bootargs "rcutorture.stall_cpu=25 rcutorture.stall_cpu_irqsoff=1" --trust-make

> Of course, to test your change, you also need the grace-period kthread to
> migrate to the stalled CPU just after interrupts are enabled.  For this,
> you need something like an 11-second stall plus something to move the
> grace-period kthread at the right (wrong?) time.  Or just run the above
> commands in a loop on a system with ample storage over night or some such.
> I see about 70MB of storage per run, so disk size shouldn't be too much
> of a problem.

Thanks!, I'll make the above run over night in a loop.