Re: [GIT PULL] percpu for 2.6.31

From: Ingo Molnar
Date: Fri Jun 19 2009 - 01:40:21 EST

* Tejun Heo <tj@xxxxxxxxxx> wrote:

> Hello, again.
> Tejun Heo wrote:
> > Oops, my apologies. I had them as floating series and apparently used
> > different base commit when applying them. I did grep run and full yes
> > build on the original quilt tree but didn't after quiltimport. Sorry.
> I digged through git changelogs to find out where it went wrong.
> I did use the same base commit when quiltimporting but when I
> updated the patches on top of mainline two days ago, I forgot to
> quilt add the file and the mce change got committed to the base
> tree instead of quilt patch. After pulling the latest master into
> the quilt branch yesterday, I updated the series for newcomers and
> everything worked fine (as the base tree change got merged by
> git). quiltimporting of course lost the base tree change and
> thinking the output gotta be identical I didn't test the final git
> tree.
> Anyways, I'm dropping the for-linus branch from percpu tree,
> fixing it up, adding patchsets scheduled for .32 release and will
> try to get it merged into #linux-next.

Please create a -git based bit for the x86 side (as i asked you
previously) - we can certainly get that upstream sooner after the
necessary amount of testing.

Condolences for trying to improve a dozen SMP architectures at once,
you've ended up with:

- being forced to rebase all the time. (This will happen in the
cycle to come too: just watch as the conflicts in linux-next
mount up with the architecture trees. Your tree will become
crappy quickly due to the combined noise.)

- the 10x patch logistics end up killing your overall quality, let
crap creep in and cause breakage even on x86.

You wasted 3 months of your life on that. Now you've learned not to
do that ever again - i've been there, done that, got the T-shirt.

Just stick your new stuff behind an ARCH_HAS flag, add it to the
architecture(s) you care about and forget about the rest - let the
remaining arch maintainers pick things up in their own pace. You'll
get 90% of the benefits to Linux with just 30% of the work.

( Many wont btw: we still dont have lockdep support in all
architectures - 3 years and counting. It's a highly useful purely
sw feature with zero hardware dependencies. Fortunately it's
well-modularized and the functionality is non-essential. Percpu
allocation is not so lucky as it's essential functionality. )

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at