comparing parallel test runs

[Martin Sebor]

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