On Sat, 15 Jul 2017, Vince Weaver wrote: > Although there is a separate issue also introduced in 4.11-rc1 that still > fails a different testcase. I'm in the middle of bisecting that one and > probably won't have the result of the bisect until Monday.
I went and bisected the other issue anyway. It wasn't in 4.11-rc1, but in 4.12-rc4. Yes, I have a test that triggered the c1582c231ea041 perf/core: Drop kernel samples even though :u is specified issue. The test was actually losing 7% of its samples, so not just a single sample here or there. The test had two events sampling, one at 100k and one at 200k so I guess every other sample would have two samples immediately back-to-back which must make it more likely to stray into the kernel. Vince