Measuring cache misses with perf about isolate HOT 5 CLOSED

I did some additional checks and I get the same result in isolate without cgroups.

from isolate.

Try echo 0 > /proc/sys/kernel/perf_event_paranoid. See https://www.kernel.org/doc/Documentation/sysctl/kernel.txt for details

from isolate.

It worked, thank you very much! However, weird things still happen: ls in an isolate box reports about 1000 cache misses, and when I run it outside of a box, I get around 30000 cache misses. I think I'm listing the same directory...

from isolate.

My guess is that because isolate is suid-root but perf is launched as a normal user, the perf counters stop the moment that it becomes root (i.e, a few thousand instructions into launching the binary). I have no authorative source to back up my theory, but I bet the kernel source will show this. If you run perf as root, the counters look right.

from isolate.

Hmm, running perf as root seems to do the trick. I'm closing this, thanks for your help!

from isolate.