Messages in this thread | | | Date | Wed, 17 Feb 2016 20:45:54 +0100 | From | Peter Zijlstra <> | Subject | Re: rcu_preempt self-detected stall on CPU from 4.5-rc3, since 3.17 |
| |
On Wed, Feb 17, 2016 at 11:28:17AM -0800, Paul E. McKenney wrote: > On Tue, Feb 16, 2016 at 09:45:49PM -0800, Paul E. McKenney wrote: > > On Tue, Feb 09, 2016 at 09:11:55PM +1100, Ross Green wrote: > > > Continued testing with the latest linux-4.5-rc3 release. > > > > > > Please find attached a copy of traces from dmesg: > > > > > > There is a lot more debug and trace data so hopefully this will shed > > > some light on what might be happening here. > > > > > > My testing remains run a series of simple benchmarks, let that run to > > > completion and then leave the system idle away with just a few daemons > > > running. > > > > > > the self detected stalls in this instance turned up after a days run time. > > > There were NO heavy artificial computational loads on the machine. > > > > It does indeed look quiet on that dmesg for a good long time. > > > > The following insanely crude not-for-mainline hack -might- be producing > > good results in my testing. It will take some time before I can claim > > statistically different results. But please feel free to give it a go > > in the meantime. (Thanks to Al Viro for pointing me in this direction.)
Your case was special in that is was hotplug triggering it, right?
I was auditing the hotplug paths involved when I fell ill two weeks ago, and have not really made any progress on that because of that :/
I'll go have another look, I had a vague feeling for a race back then, lets see if I can still remember how..
| |