linux-kernel - Re: [PATCH v4 2/2] perf report: Implement visual marker for macro fusion in annotate

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Message-ID: <0bae5548-d7eb-aa6d-f248-c550430be4ef@linux.intel.com>
Date:   Mon, 10 Jul 2017 08:31:18 +0800
From:   "Jin, Yao" <yao.jin@...ux.intel.com>
To:     Arnaldo Carvalho de Melo <acme@...nel.org>
Cc:     Jiri Olsa <jolsa@...nel.org>, peterz@...radead.org,
        Ingo Molnar <mingo@...nel.org>,
        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 v4 2/2] perf report: Implement visual marker for macro
 fusion in annotate


> I applied this one, no unnecessary parsing of cpuid done at each
> jump->target arrow rendering, much better, thanks!
>
> One thing for a follow up patch:
>
> We have this when the cursor is at a jump instruction:
>
>         │      ┌──test   %ecx,%ecx
> ->     │      ├──je     714cf
>         │      │  mov    LINES+0xb40,%edx
>         │      │  test   %edx,%edx
>         │      │↓ je     71580
>         │714cf:└─→mov    LINES+0x10c8,%eax
>
> But if we go up a line, to that "test" instruction, we get:
>
> ->     │         test   %ecx,%ecx
>         │       ↓ je     714cf
>         │         mov    LINES+0xb40,%edx
>         │         test   %edx,%edx
>         │       ↓ je     71580
>         │714cf:   mov    LINES+0x10c8,%eax
>
> I suggest that this be changed to:
>
> ->     │       ┌─test   %ecx,%ecx
>         │       ↓ je     714cf
>         │         mov    LINES+0xb40,%edx
>         │         test   %edx,%edx
>         │       ↓ je     71580
>         │714cf:   mov    LINES+0x10c8,%eax
>
> I.e. even before going to the jump instruction line with the cursor, we
> would see the fused instructions.
>
> To do that perhaps we should improve annotate_browser__draw_current_jump
> to improve that part that looks for is_valid_jump() to consider
> instructions that could be fused with jumps for the machine where the
> perf data came from, etc.
>
> But the current situation is better already, thanks for your work,
> applied!
>
> - Arnaldo

I will investigate how to do the follow-up patch.

Thanks
Jin Yao