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

[Ingo Molnar <mingo@kernel.org>]

* Stephen Rothwell <sfr@canb.auug.org.au> wrote:

> Hi Ingo,
> 
> On Wed, 17 Jun 2015 11:17:04 +0200 Ingo Molnar <mingo@kernel.org> wrote:
> >
> > * Riku Voipio <riku.voipio@iki.fi> wrote:
> > 
> > > The commit:
> > > 
> > > commit d72da4a4d973d8a0a0d3c97e7cdebf287fbe3a99
> > > Author: Peter Zijlstra <peterz@infradead.org>
> > > 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