Hi Alexandre,
On Thu, Mar 04, 2021 at 04:32:54PM +0000, Alexandre Truong wrote:
> On arm64, enable dwarf_callchain_users which will be needed
> to do a dwarf unwind in order to get the caller of the leaf frame.
>
> Signed-off-by: Alexandre Truong <[email protected]>
> Cc: John Garry <[email protected]>
> Cc: Will Deacon <[email protected]>
> Cc: Mathieu Poirier <[email protected]>
> Cc: Leo Yan <[email protected]>
> Cc: Peter Zijlstra <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> Cc: Arnaldo Carvalho de Melo <[email protected]>
> Cc: Mark Rutland <[email protected]>
> Cc: Alexander Shishkin <[email protected]>
> Cc: Jiri Olsa <[email protected]>
> Cc: Namhyung Kim <[email protected]>
> Cc: Kemeng Shi <[email protected]>
> Cc: Ian Rogers <[email protected]>
> Cc: Andi Kleen <[email protected]>
> Cc: Kan Liang <[email protected]>
> Cc: Jin Yao <[email protected]>
> Cc: Adrian Hunter <[email protected]>
> Cc: Suzuki K Poulose <[email protected]>
> Cc: Al Grant <[email protected]>
> Cc: James Clark <[email protected]>
> Cc: Wilco Dijkstra <[email protected]>
> ---
> tools/perf/builtin-report.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
> index 2a845d6cac09..93661a3eaeb1 100644
> --- a/tools/perf/builtin-report.c
> +++ b/tools/perf/builtin-report.c
> @@ -405,6 +405,10 @@ static int report__setup_sample_type(struct report *rep)
>
> callchain_param_setup(sample_type);
>
> + if (callchain_param.record_mode == CALLCHAIN_FP &&
> + strncmp(rep->session->header.env.arch, "aarch64", 7) ==
> 0)
> + dwarf_callchain_users = true;
> +
I don't have knowledge for dwarf or FP.
This patch is suspicious for me that since it only fixes the issue for
"perf report" command, but it cannot support "perf script".
I did a quick testing for "perf script" command with the test code from
patch 04, seems to me it cannot fix the fp omitting issue for
"perf script" command:
arm64_fp_test 11211 2282.355095: 176307 cycles:
aaaac2e40740 f2+0x10 (/root/arm64_fp_test)
aaaac2e4061c main+0xc (/root/arm64_fp_test)
ffff961fbd24 __libc_start_main+0xe4
(/usr/lib/aarch64-linux-gnu/libc-2.28.so)
aaaac2e4065c _start+0x34 (/root/arm64_fp_test)
Could you check for this? Thanks!
Leo
> if (rep->stitch_lbr && (callchain_param.record_mode != CALLCHAIN_LBR)) {
> ui__warning("Can't find LBR callchain. Switch off
> --stitch-lbr.\n"
> "Please apply --call-graph lbr when recording.\n");
> --
> 2.23.0
>
