Re: [PATCH v3 1/2] perf script: Show branch speculation info

From: Arnaldo Carvalho de Melo
Date: Mon Jan 30 2023 - 15:09:26 EST


Em Mon, Jan 30, 2023 at 04:04:58PM +0530, Sandipan Das escreveu:
> On 1/30/2023 11:29 AM, Sandipan Das wrote:
> > Show the branch speculation info if provided by the branch recording
> > hardware feature. This can be useful for optimizing code further.
> >
> > The speculation info is appended to the end of the list of fields so any
> > existing tools that use "/" as a delimiter for access fields via an index
> > remain unaffected. Also show "-" instead of "N/A" when speculation info
> > is unavailable because "/" is used as the field separator.
> >
> > E.g.
> >
> > $ perf record -j any,u,save_type ./test_branch
> > $ perf script --fields brstacksym
> >
> > Before:
> >
> > [...]
> > check_match+0x60/strcmp+0x0/P/-/-/0/CALL
> > do_lookup_x+0x3c5/check_match+0x0/P/-/-/0/CALL
> > [...]
> >
> > After:
> >
> > [...]
> > check_match+0x60/strcmp+0x0/P/-/-/0/CALL/NON_SPEC_CORRECT_PATH
> > do_lookup_x+0x3c5/check_match+0x0/P/-/-/0/CALL/NON_SPEC_CORRECT_PATH
> > [...]
> >
> > Signed-off-by: Sandipan Das <sandipan.das@xxxxxxx>
> > ---
> > tools/perf/builtin-script.c | 5 +++--
> > tools/perf/util/branch.c | 15 +++++++++++++++
> > tools/perf/util/branch.h | 2 ++
> > tools/perf/util/evsel.c | 15 ++++++++++++---
> > 4 files changed, 32 insertions(+), 5 deletions(-)
> >
>
> Sorry but I realized later that this change breaks the builtin branch test.
> The additional change below fixes that.

Please wait a bit for people to be able to review the other patches and
then submit a v2 series.

- Arnaldo

> diff --git a/tools/perf/tests/shell/test_brstack.sh b/tools/perf/tests/shell/test_brstack.sh
> index 59195eb80052..1c49d8293003 100755
> --- a/tools/perf/tests/shell/test_brstack.sh
> +++ b/tools/perf/tests/shell/test_brstack.sh
> @@ -30,14 +30,14 @@ test_user_branches() {
> # brstack_foo+0x14/brstack_bar+0x40/P/-/-/0/CALL
>
> set -x
> - grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND$" $TMPDIR/perf.script
> - grep -E -m1 "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/IND_CALL/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_bench\+[^ ]*/brstack_foo\+[^ ]*/CALL/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bar\+[^ ]*/CALL/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_bar\+[^ ]*/brstack_foo\+[^ ]*/RET/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_foo\+[^ ]*/brstack_bench\+[^ ]*/RET/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack_bench\+[^ ]*/brstack_bench\+[^ ]*/COND/.*$" $TMPDIR/perf.script
> + grep -E -m1 "^brstack\+[^ ]*/brstack\+[^ ]*/UNCOND/.*$" $TMPDIR/perf.script
> set +x
>
> # some branch types are still not being tested:
> @@ -57,7 +57,7 @@ test_filter() {
>
> # fail if we find any branch type that doesn't match any of the expected ones
> # also consider UNKNOWN branch types (-)
> - if grep -E -vm1 "^[^ ]*/($expect|-|( *))$" $TMPDIR/perf.script; then
> + if grep -E -vm1 "^[^ ]*/($expect|-|( *))/.*$" $TMPDIR/perf.script; then
> return 1
> fi
> }
>
>
> - Sandipan

--

- Arnaldo