On Sat, May 07, 2016 at 08:25:01AM -0700, Paul E. McKenney wrote:
> On Fri, May 06, 2016 at 04:25:16PM +1000, Ross Green wrote:
> > On Sun, Apr 3, 2016 at 6:18 PM, Paul E. McKenney
> > <paul...@linux.vnet.ibm.com> wrote:
[ . . . ]
> > Thought i would update a few runs with the linux-4.6-rc kernels.
> >
> > I have attached log outputs through dmesg showing rcu_preempt stall
> > warnings.
> >
> >
> > Thought it might be interesting for someone else to look at.
> >
> > Currently running linux-4.6-rc6 in testing.
>
> Thank you for sending these, I will look them over!
>
> Still working to reproduce this quickly enough to do real debug... :-/
And Peter Zijlstra's patch looks to have hugely reduced the rate of
occurrence of this bug in my testing:
lkml.kernel.org/r/20160523091907.gd15...@worktop.ger.corp.intel.com
Almost all of the issues I am seeing now are transient, do not trigger
RCU CPU stall warnings, and would not have been visible to me before
I upgraded my testing scripts and in-kernel code. In all the tests I
have run with Peter's fix, I have seen only one run with RCU CPU stall
warnings, and all the stalls in that run were transient, unlike those
that I was seeing before his fix.
I will of course be tracking this stuff down, but the low reproduction
rates will make it slow going.
I am guessing that you no longer see this issue?
Thanx, Paul
