Re: comparing parallel test runs

[Martin Sebor <msebor at gmail dot com>]

On 05/17/2017 11:19 PM, Andi Kleen wrote:
> Marek Polacek <polacek@redhat.com> writes:
>
> > On Wed, May 17, 2017 at 09:13:40AM -0600, Jeff Law wrote:
> > > On 05/17/2017 04:23 AM, Aldy Hernandez wrote:
> > > > Hi folks.
> > > >
> > > > I've been having troubles comparing the results of different test runs
> > > > for quite some time, and have finally decided to whine about it. Perhaps
> > > > someone can point out to whatever I may be doing wrong.
> > > >
> > > > I generally do "make check -k -j60" on two different trees and compare
> > > Make sure you've got Andi's patch installed and report back.  It's
> > > supposed to help with smaller -j loads, but it's unclear if it's enough
> > > to address the problems with higher loads like you're using.
> >
> > I'm still seeing spurious tree-prof failures there (with -j48).
>
> Do they go away if you run first (as root)
>
> echo 5000 > /proc/sys/kernel/perf_event_mlock_kb
>
> first?

I tried three runs of the profiling tests and the failures did
clear up with the increased setting.

Martin