Re: [PATCH RFC] sched: Add a per-thread core scheduling interface

Linus Torvalds
2020-05-22T16:33:55Z

On Thu, May 21, 2020 at 2:58 PM Jesse Barnes <jsbarnes@google.com> wrote:
>
> Expanding on this a little, we're working on a couple of projects that
> should provide results like these for upstream. One is continuously
> rebasing our upstream backlog onto new kernels for testing purposes
> (the idea here is to make it easier for us to update kernels on
> Chromebooks),

Lovely. Not just for any performance work that comes out of this, but
hopefully this means that we'll also have quick problem reports if
something happens that affects chrome.

There's certainly been issues on the server side of google where we
made changes (*cough*cgroup*cough*) which didn't make anybody really
blink until years after the fact.. Which ends up being very
inconvenient when other parts of the community have been using the new
features for years.

> and the second is to drive more stuff into the
> kernelci.org infrastructure. Given the test environments we have in
> place now, we can probably get results from our continuous rebase
> project first and provide those against -rc releases if that's
> something you'd be interested in.

I think the more automated (or regular, or close-to-upstream)
real-world testing that we get, the better off we are. We have a
number of regular distributions that track the upstream kernel fairly
closely, so we get a fair amount of coverage for the normal desktop
loads.

And the bots are doing great, but they tend to test very specific
things (in the case of "syzbot" the "specific" thing is obviously
pretty far-ranging, but it's still very small details). And latency
has always been harder to really test (outside of the truly trivial
microbenchmarks), so the fact that it sounds like you're going to test
not only a different environment than the usual distros but have a few
macro-level latency tests just sounds lovely in general.

Let's see how lovely I think it is once you start sending regression reports..

Linus