Re: Please can I have a stable KCSAN branch for 5.8?

From: Will Deacon
Date: Wed May 06 2020 - 10:41:52 EST


Hi Paul,

Cheers for the quick reply!

On Wed, May 06, 2020 at 07:36:16AM -0700, Paul E. McKenney wrote:
> On Wed, May 06, 2020 at 02:28:17PM +0100, Will Deacon wrote:
> > I'm looking to rebase my READ_ONCE() series [1] on top of the KCSAN patches
> > so that we can get them in for 5.8. However, tip/locking/kcsan seems to be
> > missing some bits:
> >
> > * An update to checkpatch.pl to warn about missing comments for
> > data_race():
> >
> > https://lore.kernel.org/r/20200401101714.44781-1-elver@xxxxxxxxxx
>
> For some reason, I thought this was going up some other tree, but I do
> not see it in -next. So unless I hear otherwise, I will pull it into
> the v5.8 kcsan branch.

Brill, thanks.

> > * I'm unable to apply these two patches from Marco that are needed for
> > my READ_ONCE() work:
> >
> > https://lore.kernel.org/lkml/20200424154730.190041-1-elver@xxxxxxxxxx/
> >
> > I think these depend on stuff that has been queued by Paul, and appears
> > in linux-next, but to be honest with you I'm quite confused about what
> > is queued for 5.8 and what isn't.
>
> This one is queued, but I currently have it in the v5.9 pile (but
> tentatively for v5.8). Unless Marco tells me otherwise, I will move it
> to the v5.8 branch, which will be part of my pull request next week.

Great, then this would all show up on tip/locking/kscan, right?

> > What's the best base for me to use?
>
> The -next tree has the latter, but not yet the former.

That probably means -next is good enough for me to cook a new version of my
series, and then I can make a proper branch next week.

> Hopefully we can get this straightened out, and please accept my apologies
> for the hassle!

No need to apologise, I just couldn't figure out what was what and decided
it was easier to ask the experts ;)

Cheers again,

Will