linux-kernel - Re: [PATCH v3] perf annotate: Add itrace options support

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Message-ID: <52532fa6-8883-ee5a-7047-53415f9d34f9@huawei.com>
Date:   Tue, 15 Jun 2021 15:19:48 +0800
From:   Yang Jihong <yangjihong1@...wei.com>
To:     Leo Yan <leo.yan@...aro.org>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>
CC:     <peterz@...radead.org>, <mingo@...hat.com>, <acme@...nel.org>,
        <mark.rutland@....com>, <alexander.shishkin@...ux.intel.com>,
        <jolsa@...hat.com>, <namhyung@...nel.org>,
        <linux-perf-users@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3] perf annotate: Add itrace options support

Hello, Leo and Arnaldo,

On 2021/6/15 12:04, Leo Yan wrote:
> Hi Jihong,
> 
> Loop in Adrain to be aware this AUX trace change.
> 
> On Tue, Jun 15, 2021 at 10:40:36AM +0800, Yang Jihong wrote:
>> The "auxtrace_info" and "auxtrace" functions are not set in "tool" member of
>> "annotate". As a result, perf annotate does not support parsing itrace data.
>>
>> Before:
>>
>>    # perf record -e arm_spe_0/branch_filter=1/ -a sleep 1
>>    [ perf record: Woken up 9 times to write data ]
>>    [ perf record: Captured and wrote 20.874 MB perf.data ]
>>    # perf annotate --stdio
>>    Error:
>>    The perf.data data has no samples!
>>
>> Solution:
>> 1.Add itrace options in help,
>> 2.Set hook functions of "auxtrace_info" and "auxtrace" in perf_tool.
>>
>> After:
>>
>>    # perf record --all-user -e arm_spe_0/branch_filter=1/ ls
>>    Couldn't synthesize bpf events.
>>    perf.data
>>    [ perf record: Woken up 1 times to write data ]
>>    [ perf record: Captured and wrote 0.010 MB perf.data ]
>>    # perf annotate --stdio
> 
>>     Percent |      Source code & Disassembly of libc-2.28.so for branch-miss (1 samples, percent: local period)
>>    ------------------------------------------------------------------------------------------------------------
>>             :
>>             :
>>             :
>>             :           Disassembly of section .text:
>>             :
>>             :           0000000000066180 <__getdelim@@GLIBC_2.17>:
>>        0.00 :   66180:  stp     x29, x30, [sp, #-96]!
>>        0.00 :   66184:  cmp     x0, #0x0
>>        0.00 :   66188:  ccmp    x1, #0x0, #0x4, ne  // ne = any
>>        0.00 :   6618c:  mov     x29, sp
>>        0.00 :   66190:  stp     x24, x25, [sp, #56]
>>        0.00 :   66194:  stp     x26, x27, [sp, #72]
>>        0.00 :   66198:  str     x28, [sp, #88]
>>        0.00 :   6619c:  b.eq    66450 <__getdelim@@GLIBC_2.17+0x2d0>  // b.none
>>        0.00 :   661a0:  stp     x22, x23, [x29, #40]
> 
> [...]
> 
> Nitpick: the above example is not typical for annotation, since it
> doesn't show any C source code with samples.  At my side, I tested this
> patch and confirmed the patch works well with below commands:
> 
>    # gcc -ggdb -O0 -o task_migration task_migration.c
>    # perf record -e cs_etm/@..._etr0/u --per-thread ./task_migration
>    # perf annotate --itrace=i1000 --stdio
> 
> The complete annotation result can be reviewed at [1].
> 
> Thus for this patch:
> 
> Tested-by: Leo Yan <leo.yan@...aro.org>
> 
> [1] https://paste.ubuntu.com/p/pHz74MYRPJ/
> 
> [...]
> .
> 
Thank you very much for the detailed testing of this patch :)

Yes, this example may not be well written.
Arnaldo, please check whether the commit message needs to be modified. 
If yes, I will resubmit a new v4 patch

Thanks,
Jihong