linux-kernel - Re: [PATCH v1 1/2] perf report: Check for fused instruction pair

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Message-ID: <9cc30de7-826d-1bfc-944d-aa9eb9b6803b@linux.intel.com>
Date:   Mon, 19 Jun 2017 10:58:55 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     jolsa@...nel.org, peterz@...radead.org, mingo@...hat.com,
        alexander.shishkin@...ux.intel.com, Linux-kernel@...r.kernel.org,
        ak@...ux.intel.com, kan.liang@...el.com, yao.jin@...el.com
Subject: Re: [PATCH v1 1/2] perf report: Check for fused instruction pair



On 6/17/2017 12:21 AM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Jun 14, 2017 at 10:53:40AM +0800, Jin Yao escreveu:
>> Macro fusion merges two instructions to a single micro-op. Intel
>> core platform performs this hardware optimization under limited
>> circumstances. For example, CMP + JCC can be "fused" and executed
>> /retired together. While with sampling this can result in the
>> sample sometimes being on the JCC and sometimes on the CMP.
>> So for the fused instruction pair, they could be considered
>> together.
> doing it as a weak function that will be overriden by the host arch
> doesn't work, as we also support cross-annotation. So you have to take
> into account perf_evsel__env_arch(evsel), etc.
>
> Please search for perf_evsel__env_arch(evsel) in the annotation source
> files to see how it is used.
>
> - Arnaldo
>   
Hi Arnaldo,

Thanks so much for pointing out that the weak function doesn't work.

I have changed it to arch-specific function and just send out v2 series 
for reviewing.

Thanks
Jin Yao