Re: [PATCH] tools/perf, rbtree: Add RCU wrappers to make rbtree.h usable in user-space

From: Ingo Molnar
Date: Mon Jul 06 2015 - 05:41:31 EST



* Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:

> Hi Ingo,
>
> On Wed, 17 Jun 2015 11:17:04 +0200 Ingo Molnar <mingo@xxxxxxxxxx> wrote:
> >
> > * Riku Voipio <riku.voipio@xxxxxx> wrote:
> >
> > > The commit:
> > >
> > > commit d72da4a4d973d8a0a0d3c97e7cdebf287fbe3a99
> > > Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > > Date: Wed May 27 11:09:36 2015 +0930
> > >
> > > rbtree: Make lockless searches non-fatal
> > >
> > > Adds <linux/rcupdate.h> to rbtree.h, which in turn is included from perf userspace
> > > headers. Now building tools/perf will fail with hundreds of lines of gcc complaining
> > > about kernel defines not available. Reverting the patch makes perf build again.
> > > This is with gcc-4.9 from debian but I don't think it's compiler specific.
> >
> > Does the patch below make things work?
> >
> > This fix could go into the modules tree, as this commit came via Rusty.
> >
> > Stephen, feel free to add:
> >
> > make -C tools/perf
> >
> > to the linux-next build tests. It's always supposed to build without failure, in
> > pretty much whatever x86 distro you run your build tests on.
>
> OK, I have started doing that, but int order to make it build at all, I
> have added the patch below to my fixes tree (since the breakage is now
> in Linus' tree).
>
> This means that it will get a conflict with the tip tree tomorrow, but
> I will just fix the conflict by using the version from the tip tree.
> Once the tip tree fixes are sent to Linus, I will drop this patch from
> my fixes tree.

On next linux-next iteration you should be able to just drop your merge conflict
resolution, and use the -tip tree as-is with no extra fixups.

Thanks,

Ingo
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