On Thu, 11 Jan 2018, Peter Zijlstra wrote: > On Thu, Jan 11, 2018 at 01:21:12PM -0600, Josh Poimboeuf wrote: > > Yuck. This time it was stack recursion on the entry stack. In the > > previous error, recursion was detected on the IRQ stack. Otherwise they > > look quite similar. > > > > Was that also with nopti? > > Both with pti enabled, nopti makes things work again.
I think I have hit those errors even with pti disabled but now I'll have to double check. > > I haven't had a chance to try it yet, any idea if these would be > > recreatable in a VM? > > Good question; typically we run the perf fuzzer on read hardware because > the PMU doesn't virtualize much. But if software perf is enough to > trigger this, that would certainly help. I can only trigger them with perf_event_paranoid=0 (not with perf_event_paranoid=2) so it might depend on how much of the PMU is virtualized. Vince
