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

[Yang Jihong]

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/@tmc_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@xxxxxxxxxx>
>
> [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