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Subject: Re: [PATCH v5 3/5] perf tools: sync addition of PERF_MEM_SNOOPX_PEER
From:   German Gomez <german.gomez@arm.com>
To:     Ali Saidi <alisaidi@amazon.com>, linux-kernel@vger.kernel.org,
        linux-perf-users@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, leo.yan@linaro.org,
        acme@kernel.org
Cc:     benh@kernel.crashing.org, Nick.Forrington@arm.com,
        alexander.shishkin@linux.intel.com, andrew.kilroy@arm.com,
        james.clark@arm.com, john.garry@huawei.com, jolsa@kernel.org,
        kjain@linux.ibm.com, lihuafei1@huawei.com, mark.rutland@arm.com,
        mathieu.poirier@linaro.org, mingo@redhat.com, namhyung@kernel.org,
        peterz@infradead.org, will@kernel.org
References: <20220408195344.32764-1-alisaidi@amazon.com>
 <20220408195344.32764-4-alisaidi@amazon.com>
 <39448754-adf5-f1ba-25e7-8ee3d76f0159@arm.com>
Message-ID: <47ec29fe-75ea-62ef-447b-1164569616de@arm.com>
Date:   Mon, 11 Apr 2022 15:35:52 +0100
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On 11/04/2022 11:26, German Gomez wrote:
> On 08/04/2022 20:53, Ali Saidi wrote:
>> Add a flag to the perf mem data struct to signal that a request caused a
>> cache-to-cache transfer of a line from a peer of the requestor and
>> wasn't sourced from a lower cache level.  The line being moved from one
>> peer cache to another has latency and performance implications. On Arm64
>> Neoverse systems the data source can indicate a cache-to-cache transfer
>> but not if the line is dirty or clean, so instead of overloading HITM
>> define a new flag that indicates this type of transfer.
> I think it's fine to merge this and the previous commit rather than have
> two commits with the same msg.
>

I take it back. It has been pointed out to me that having the separation
is normal/ok. So my comment doesn't apply.