Date: Fri, 1 Sep 2017 17:03:52 -0400 (EDT)
From: Vince Weaver <vince@deater.net>
To: Peter Zijlstra <peterz@infradead.org>
cc: Alexey Budankov <alexey.budankov@linux.intel.com>,
        Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Andi Kleen <ak@linux.intel.com>, Kan Liang <kan.liang@intel.com>,
        Dmitri Prokhorov <Dmitry.Prohorov@intel.com>,
        Valery Cherepennikov <valery.cherepennikov@intel.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Stephane Eranian <eranian@google.com>,
        David Carrillo-Cisneros <davidcc@google.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [RFC][PATCH] perf: Rewrite enabled/running timekeeping
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On Thu, 31 Aug 2017, Peter Zijlstra wrote:

> So the below completely rewrites timekeeping (and probably breaks
> world) but does away with the need to touch events that don't get
> scheduled.
> 
> Esp the cgroup stuff is entirely untested since I simply don't know how
> to operate that. I did run Vince's tests on it, and I think it doesn't
> regress, but I'm near a migraine so I can't really see straight atm.
> 
> Vince, Stephane, could you guys have a peek?

I have to admit that I *always* got lost trying to figure out the old 
so I might not be the best person to review the changes.

I did try running the perf_event_tests on a few machines and they all pass.

I also ran the PAPI tests and a few of the multiplexing tests fail about 
10% of the time but I think they also fail 10% of the time with the old 
code too.  I need to figure out why that's happening but it's likely a 
PAPI issue not a kernel one.

Vince