Messages in this thread | | | From | Vince Weaver <> | Date | Thu, 11 Jan 2018 14:57:25 -0500 (EST) | Subject | Re: perf: perf_fuzzer quickly locks up on 4.15-rc7 |
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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
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