On Mon, Feb 29, 2016 at 01:07:23PM +0000, Marc Zyngier wrote:

On 25/02/16 02:02, Shannon Zhao wrote:

quoted

On 2016/2/25 1:52, Will Deacon wrote:

quoted

On Wed, Feb 24, 2016 at 01:08:21PM +0800, Shannon Zhao wrote:

quoted

From: Shannon Zhao <redacted>

To use the ARMv8 PMU related register defines from the KVM code, we move
the relevant definitions to asm/perf_event.h header file and rename them
with prefix ARMV8_PMU_.

Signed-off-by: Anup Patel <redacted>
Signed-off-by: Shannon Zhao <redacted>
Acked-by: Marc Zyngier <redacted>
Reviewed-by: Andrew Jones <redacted>
---
 arch/arm64/include/asm/perf_event.h | 35 +++++++++++++++++++
 arch/arm64/kernel/perf_event.c      | 68 ++++++++++---------------------------
 2 files changed, 52 insertions(+), 51 deletions(-)

Looks fine to me, but we're going to get some truly horrible conflicts
in -next.

I'm open to suggestions on the best way to handle this, but one way
would be:

  1. Duplicate all the #defines privately in KVM (queue via kvm tree)

This way seems not proper I think.

quoted

  2. Rebase this patch onto my perf/updates branch [1] (queue via me)

While to this series, it really relies on the perf_event.h to compile
and test, so maybe for KVM-ARM and KVM maintainers it's not proper.

quoted

  3. Patch at -rc1 dropping the #defines from (1) and moving to the new
     perf_event.h stuff

I vote for this way. Since the patch in [1] is small and nothing else
relies on them, I think it would be simple to rebase them onto this series.

quoted

Thoughts?

Anyway, there are only 3 lines which have conflicts. I'm not sure
whether we could handle this when we merge them.

I think you're missing the point:

- We want both the arm64 perf and KVM trees to be easy to merge
- The conflicts are not that simple to resolve
- We want these conflicts to be solved before it hits Linus' tree

With that in mind, here's what I'm suggesting we merge as a first patch:

https://git.kernel.org/cgit/linux/kernel/git/kvmarm/kvmarm.git/commit/?h=queue&id=2029b4b02691ec6ebba3d281068e783353d7e108

Acked-by: Will Deacon <redacted>

Will