Petter Reinholdtsen writes:
> [Lluís Vilanova]
>> The package currently fails to run its tests during build due to
>> insufficient permissions to access Linux's perf interface.
> Is there some way to figure out if such permissions are missing or not?
> On my machine, where the build work, the value of
> /proc/sys/kernel/perf_event_paranoid is '1', so '0' is not required.
> I notice the autobuilders work, the ci.debian.org builders work, but the
> reproducable build builders do not. No idea what the difference is.
I've rechecked, and things seem to be a bit different...
For some reason my kernel (4.7.0-1-amd64) ignores changes through the file
system. It's more reliable to use:
/sbin/sysctl kernel.perf_event_paranoid
sudo /sbin/sysctl kernel.perf_event_paranoid=<value>
Now, I've tried on a nother machine, and (strangely) the kernel starts with a
perf paranoid level of 3, which is not even documented as a valid value on
Linux's source code.
Getting it down to 2 is sufficient to run the check successfully.
A possible check could be:
if [ `/sbin/sysctl kernel.perf_event_paranoid` -gt 2 ]; then
echo "ERROR: perf is too paranoid for us"
exit 1
fi
This would build-depend on procps (which installs sysctl).
Cheers,
Lluis
