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Date:   Mon, 5 Jun 2023 16:30:51 -0300
From:   Arnaldo Carvalho de Melo <acme@kernel.org>
To:     Ian Rogers <irogers@google.com>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Ingo Molnar <mingo@redhat.com>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@kernel.org>,
        Namhyung Kim <namhyung@kernel.org>,
        Adrian Hunter <adrian.hunter@intel.com>,
        James Clark <james.clark@arm.com>,
        Andrii Nakryiko <andrii@kernel.org>,
        Eduard Zingerman <eddyz87@gmail.com>,
        linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org,
        Ahmad Yasin <ahmad.yasin@intel.com>,
        Stephane Eranian <eranian@google.com>,
        Andi Kleen <ak@linux.intel.com>,
        Perry Taylor <perry.taylor@intel.com>,
        Samantha Alt <samantha.alt@intel.com>,
        Caleb Biggers <caleb.biggers@intel.com>,
        Weilin Wang <weilin.wang@intel.com>,
        Edward Baker <edward.baker@intel.com>,
        "Liang, Kan" <kan.liang@linux.intel.com>
Subject: Re: [PATCH v1 1/2] perf expr: Make the evaluation of & and | logical
 and lazy
Message-ID: <ZH436w4Sesq57iu9@kernel.org>
References: <20230504195803.3331775-1-irogers@google.com>
 <2abe618d-a2c4-3b22-ac9d-37bc91d05d41@linux.intel.com>
 <CAP-5=fX_j-iwuHBekCDFzQUGaOqigTXtyUa6npNCuR7ktF-3_A@mail.gmail.com>
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Em Mon, Jun 05, 2023 at 10:32:18AM -0700, Ian Rogers escreveu:
> On Thu, May 18, 2023 at 12:47 PM Liang, Kan <kan.liang@linux.intel.com> wrote:
> >
> >
> >
> > On 2023-05-04 3:58 p.m., Ian Rogers wrote:
> > > Currently the & and | operators are only used in metric thresholds
> > > like (from the tma_retiring metric):
> > > tma_retiring > 0.7 | tma_heavy_operations > 0.1
> > >
> > > Thresholds are always computed when present, but a lack events may
> > > mean the threshold can't be computed. This happens with the option
> > > --metric-no-threshold for say the metric tma_retiring on Tigerlake
> > > model CPUs. To fully compute the threshold tma_heavy_operations is
> > > needed and it needs the extra events of IDQ.MS_UOPS,
> > > UOPS_DECODED.DEC0, cpu/UOPS_DECODED.DEC0,cmask=1/ and
> > > IDQ.MITE_UOPS. So --metric-no-threshold is a useful option to reduce
> > > the number of events needed and potentially multiplexing of events.
> > >
> > > Rather than just fail threshold computations like this, we may know a
> > > result from just the left or right-hand side. So, for tma_retiring if
> > > its value is "> 0.7" we know it is over the threshold. This allows the
> > > metric to have the threshold coloring, when possible, without all the
> > > counters being programmed.
> > >
> > > Signed-off-by: Ian Rogers <irogers@google.com>
> > > ---
> >
> > The patch works well on my machine.
> >
> > Tested-by: Kan Liang <kan.liang@linux.intel.com>
> >
> > Thanks,
> > Kan
> 
> Arnaldo, could we take this set?

Thanks, applied.

- Arnaldo

 
> Thanks,
> Ian
> 
> > >  tools/perf/tests/expr.c | 40 +++++++++++++++++++
> > >  tools/perf/util/expr.y  | 86 +++++++++++++++++++++++++++++++++--------
> > >  2 files changed, 109 insertions(+), 17 deletions(-)
> > >
> > > diff --git a/tools/perf/tests/expr.c b/tools/perf/tests/expr.c
> > > index cbf0e0c74906..45c7fedb797a 100644
> > > --- a/tools/perf/tests/expr.c
> > > +++ b/tools/perf/tests/expr.c
> > > @@ -184,6 +184,46 @@ static int test__expr(struct test_suite *t __maybe_unused, int subtest __maybe_u
> > >                       NULL, ctx) == 0);
> > >       TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 0);
> > >
> > > +     /* The expression is a constant 0.0 without needing to evaluate EVENT1. */
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("0 & EVENT1 > 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 0);
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("EVENT1 > 0 & 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 0);
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("1 & EVENT1 > 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 1);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1", &val_ptr));
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("EVENT1 > 0 & 1", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 1);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1", &val_ptr));
> > > +
> > > +     /* The expression is a constant 1.0 without needing to evaluate EVENT1. */
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("1 | EVENT1 > 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 0);
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("EVENT1 > 0 | 1", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 0);
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("0 | EVENT1 > 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 1);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1", &val_ptr));
> > > +     expr__ctx_clear(ctx);
> > > +     TEST_ASSERT_VAL("find ids",
> > > +                     expr__find_ids("EVENT1 > 0 | 0", NULL, ctx) == 0);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__size(ctx->ids) == 1);
> > > +     TEST_ASSERT_VAL("find ids", hashmap__find(ctx->ids, "EVENT1", &val_ptr));
> > > +
> > >       /* Test toplogy constants appear well ordered. */
> > >       expr__ctx_clear(ctx);
> > >       TEST_ASSERT_VAL("#num_cpus", expr__parse(&num_cpus, ctx, "#num_cpus") == 0);
> > > diff --git a/tools/perf/util/expr.y b/tools/perf/util/expr.y
> > > index 250e444bf032..6b110f9f95c9 100644
> > > --- a/tools/perf/util/expr.y
> > > +++ b/tools/perf/util/expr.y
> > > @@ -123,20 +123,6 @@ static struct ids handle_id(struct expr_parse_ctx *ctx, char *id,
> > >   * constant value using OP. Its invariant that there are no ids.  If computing
> > >   * ids for non-constants union the set of IDs that must be computed.
> > >   */
> > > -#define BINARY_LONG_OP(RESULT, OP, LHS, RHS)                         \
> > > -     if (!compute_ids || (is_const(LHS.val) && is_const(RHS.val))) { \
> > > -             assert(LHS.ids == NULL);                                \
> > > -             assert(RHS.ids == NULL);                                \
> > > -             if (isnan(LHS.val) || isnan(RHS.val)) {                 \
> > > -                     RESULT.val = NAN;                               \
> > > -             } else {                                                \
> > > -                     RESULT.val = (long)LHS.val OP (long)RHS.val;    \
> > > -             }                                                       \
> > > -             RESULT.ids = NULL;                                      \
> > > -     } else {                                                        \
> > > -             RESULT = union_expr(LHS, RHS);                          \
> > > -     }
> > > -
> > >  #define BINARY_OP(RESULT, OP, LHS, RHS)                                      \
> > >       if (!compute_ids || (is_const(LHS.val) && is_const(RHS.val))) { \
> > >               assert(LHS.ids == NULL);                                \
> > > @@ -213,9 +199,75 @@ expr: NUMBER
> > >  }
> > >  | ID                         { $$ = handle_id(ctx, $1, compute_ids, /*source_count=*/false); }
> > >  | SOURCE_COUNT '(' ID ')'    { $$ = handle_id(ctx, $3, compute_ids, /*source_count=*/true); }
> > > -| expr '|' expr { BINARY_LONG_OP($$, |, $1, $3); }
> > > -| expr '&' expr { BINARY_LONG_OP($$, &, $1, $3); }
> > > -| expr '^' expr { BINARY_LONG_OP($$, ^, $1, $3); }
> > > +| expr '|' expr
> > > +{
> > > +     if (is_const($1.val) && is_const($3.val)) {
> > > +             assert($1.ids == NULL);
> > > +             assert($3.ids == NULL);
> > > +             $$.ids = NULL;
> > > +             $$.val = (fpclassify($1.val) == FP_ZERO && fpclassify($3.val) == FP_ZERO) ? 0 : 1;
> > > +     } else if (is_const($1.val)) {
> > > +             assert($1.ids == NULL);
> > > +             if (fpclassify($1.val) == FP_ZERO) {
> > > +                     $$ = $3;
> > > +             } else {
> > > +                     $$.val = 1;
> > > +                     $$.ids = NULL;
> > > +                     ids__free($3.ids);
> > > +             }
> > > +     } else if (is_const($3.val)) {
> > > +             assert($3.ids == NULL);
> > > +             if (fpclassify($3.val) == FP_ZERO) {
> > > +                     $$ = $1;
> > > +             } else {
> > > +                     $$.val = 1;
> > > +                     $$.ids = NULL;
> > > +                     ids__free($1.ids);
> > > +             }
> > > +     } else {
> > > +             $$ = union_expr($1, $3);
> > > +     }
> > > +}
> > > +| expr '&' expr
> > > +{
> > > +     if (is_const($1.val) && is_const($3.val)) {
> > > +             assert($1.ids == NULL);
> > > +             assert($3.ids == NULL);
> > > +             $$.val = (fpclassify($1.val) != FP_ZERO && fpclassify($3.val) != FP_ZERO) ? 1 : 0;
> > > +             $$.ids = NULL;
> > > +     } else if (is_const($1.val)) {
> > > +             assert($1.ids == NULL);
> > > +             if (fpclassify($1.val) != FP_ZERO) {
> > > +                     $$ = $3;
> > > +             } else {
> > > +                     $$.val = 0;
> > > +                     $$.ids = NULL;
> > > +                     ids__free($3.ids);
> > > +             }
> > > +     } else if (is_const($3.val)) {
> > > +             assert($3.ids == NULL);
> > > +             if (fpclassify($3.val) != FP_ZERO) {
> > > +                     $$ = $1;
> > > +             } else {
> > > +                     $$.val = 0;
> > > +                     $$.ids = NULL;
> > > +                     ids__free($1.ids);
> > > +             }
> > > +     } else {
> > > +             $$ = union_expr($1, $3);
> > > +     }
> > > +}
> > > +| expr '^' expr
> > > +{
> > > +     if (is_const($1.val) && is_const($3.val)) {
> > > +             assert($1.ids == NULL);
> > > +             assert($3.ids == NULL);
> > > +             $$.val = (fpclassify($1.val) == FP_ZERO) != (fpclassify($3.val) == FP_ZERO) ? 1 : 0;
> > > +             $$.ids = NULL;
> > > +     } else {
> > > +             $$ = union_expr($1, $3);
> > > +     }
> > > +}
> > >  | expr '<' expr { BINARY_OP($$, <, $1, $3); }
> > >  | expr '>' expr { BINARY_OP($$, >, $1, $3); }
> > >  | expr '+' expr { BINARY_OP($$, +, $1, $3); }

-- 

- Arnaldo