From mboxrd@z Thu Jan  1 00:00:00 1970
From: marc.zyngier@arm.com (Marc Zyngier)
Date: Mon, 29 Feb 2016 13:59:49 +0000
Subject: [PATCH v13 01/20] ARM64: Move PMU register related defines to
 asm/perf_event.h
In-Reply-To: <56D4428B.5000505@arm.com>
References: <1456290520-10012-1-git-send-email-zhaoshenglong@huawei.com>
 <1456290520-10012-2-git-send-email-zhaoshenglong@huawei.com>
 <20160224175247.GE12471@arm.com> <56CE6098.8070001@huawei.com>
 <56D4428B.5000505@arm.com>
Message-ID: <56D44ED5.8070606@arm.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 29/02/16 13:07, Marc Zyngier wrote:
> Shannon,
> 
> On 25/02/16 02:02, Shannon Zhao wrote:
>>
>>
>> On 2016/2/25 1:52, Will Deacon wrote:
>>> On Wed, Feb 24, 2016 at 01:08:21PM +0800, Shannon Zhao wrote:
>>>> From: Shannon Zhao <shannon.zhao@linaro.org>
>>>>
>>>> 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 <anup.patel@linaro.org>
>>>> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
>>>> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
>>>> Reviewed-by: Andrew Jones <drjones@redhat.com>
>>>> ---
>>>>  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.
>>
>>>   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.
>>
>>>   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.
>>
>>> 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
> 
> Once this and the perf/updates branch are merged, we can add one last
> patch reverting this hack and actually doing the renaming work (Will has
> posted a resolution for most of the new things).

For the record, here's the patch I propose we merge once everything gets
into mainline:

https://git.kernel.org/cgit/linux/kernel/git/kvmarm/kvmarm.git/commit/?h=queue&id=ba1e09b2f2cd2d5cc5cfdb76e96460aee1bd9482

	M.
-- 
Jazz is not dead. It just smells funny...