Re: Reduced build and test coverage

On Tuesday, September 19, 2023 18:12 CEST, Mark Brown <[email protected]> wrote:

> On Tue, Sep 19, 2023 at 04:44:06PM +0200, Ricardo Cañuelo wrote:
> > On mar, sep 19 2023 at 15:31:31, Mark Brown <[email protected]> wrote:
> > > If we're doing this -next would be very helpful too.
> 
> > Does it make sense to bisect -next, though? Considering that it's
> > constantly rebased, so I don't think it has a coherent and "linear" log
> > like mainline. That means that bisections aren't guaranteed to work on
> > it. Is that right?
> 
> When bisecting -next you should generally bisect it against the mainline
> it was based on.

Yes that's how the KernelCI bisection works. It's the most useful branch to bisect automatically precisely because it's rebased every day with thousands of commits, so a bisection takes between 10 and 15 iterations and it's painful to do manually. And that's where most of the bugs are.  Then mainline, stable and stable-rc are the other critical trees to cover so it makes sense to enable them first.

We've discussed enabling bisections again with sysadmins and I think we can have this done in a week or two.  Other issues are about measuring costs empirically for different parts of the system and adding a filter in the legacy back end to avoid flooding Jenkins with jobs that won't get run (they still use up all the RAM).

Cheers,
Guillaume