On Fri, 19 Aug 2016, Peter Zijlstra wrote: > On Thu, Aug 18, 2016 at 10:46:31AM -0400, Vince Weaver wrote: > > On Thu, 18 Aug 2016, Vince Weaver wrote: > > > > > Tried the perf_fuzzer on my A10 fam15h/model13h system with 4.8-rc2 and it > > > falls over more or less immediately. > > > > > > This maps to variable_test_bit() > > > called by ctx = find_get_context(pmu, task, event); > > > in kernel/events/core.c:9467 > > > > > > It happens quickly enough I can probably track down the exact event that > > > causes this, if needed. > > > > I have a one line reproducer: > > > > perf stat -a -e amd_nb/config=0x37,config1=0x20/ /bin/ls > > OK, cannot reproduce on my fam15h/model1h. I'll go dig through the > various manuals to see if I can spot the fail. > > Huang could you either prod someone at AMD or do yourself, audit the AMD > perf code for all the various new models?
OK, this is weird. I rebooted (didn't patch the kernel, just rebooted) and I can't reproduce the original problem at all. It was perfectly repeatable before I rebooted, dumped an OOPS message every time. Sadly I don't have the fuzzer logs that originally triggered the bug (need more serial/USB cables. Actually no, I need more null-modem adapters). Let me look into this a bit more. Vince
