perf bpf filter: Add 'pid' sample data support
authorNamhyung Kim <namhyung@kernel.org>
Tue, 14 Mar 2023 23:42:32 +0000 (16:42 -0700)
committerArnaldo Carvalho de Melo <acme@redhat.com>
Wed, 15 Mar 2023 14:08:36 +0000 (11:08 -0300)
The pid is special because it's saved in the PERF_SAMPLE_TID together.
So it needs to differenciate tid and pid using the 'part' field in the
perf bpf filter entry struct.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230314234237.3008956-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tools/perf/util/bpf-filter.c
tools/perf/util/bpf-filter.h
tools/perf/util/bpf-filter.l
tools/perf/util/bpf-filter.y
tools/perf/util/bpf_skel/sample-filter.h
tools/perf/util/bpf_skel/sample_filter.bpf.c

index 7bd6f2e..743c69f 100644 (file)
@@ -36,6 +36,7 @@ int perf_bpf_filter__prepare(struct evsel *evsel)
        list_for_each_entry(expr, &evsel->bpf_filters, list) {
                struct perf_bpf_filter_entry entry = {
                        .op = expr->op,
+                       .part = expr->part,
                        .flags = expr->sample_flags,
                        .value = expr->val,
                };
@@ -76,7 +77,7 @@ u64 perf_bpf_filter__lost_count(struct evsel *evsel)
        return skel ? skel->bss->dropped : 0;
 }
 
-struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags,
+struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part,
                                                       enum perf_bpf_filter_op op,
                                                       unsigned long val)
 {
@@ -85,6 +86,7 @@ struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flag
        expr = malloc(sizeof(*expr));
        if (expr != NULL) {
                expr->sample_flags = sample_flags;
+               expr->part = part;
                expr->op = op;
                expr->val = val;
        }
index f0c6676..3f8827b 100644 (file)
@@ -9,6 +9,7 @@
 struct perf_bpf_filter_expr {
        struct list_head list;
        enum perf_bpf_filter_op op;
+       int part;
        unsigned long sample_flags;
        unsigned long val;
 };
@@ -16,7 +17,7 @@ struct perf_bpf_filter_expr {
 struct evsel;
 
 #ifdef HAVE_BPF_SKEL
-struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags,
+struct perf_bpf_filter_expr *perf_bpf_filter_expr__new(unsigned long sample_flags, int part,
                                                       enum perf_bpf_filter_op op,
                                                       unsigned long val);
 int perf_bpf_filter__parse(struct list_head *expr_head, const char *str);
index f6c0b74..ec12fc4 100644 (file)
 
 static int sample(unsigned long sample_flag)
 {
-       perf_bpf_filter_lval.sample = sample_flag;
+       perf_bpf_filter_lval.sample.type = sample_flag;
+       perf_bpf_filter_lval.sample.part = 0;
+       return BFT_SAMPLE;
+}
+
+static int sample_part(unsigned long sample_flag, int part)
+{
+       perf_bpf_filter_lval.sample.type = sample_flag;
+       perf_bpf_filter_lval.sample.part = part;
        return BFT_SAMPLE;
 }
 
@@ -56,6 +64,7 @@ ident         [_a-zA-Z][_a-zA-Z0-9]+
 ip             { return sample(PERF_SAMPLE_IP); }
 id             { return sample(PERF_SAMPLE_ID); }
 tid            { return sample(PERF_SAMPLE_TID); }
+pid            { return sample_part(PERF_SAMPLE_TID, 1); }
 cpu            { return sample(PERF_SAMPLE_CPU); }
 time           { return sample(PERF_SAMPLE_TIME); }
 addr           { return sample(PERF_SAMPLE_ADDR); }
index 13eca61..0ca6532 100644 (file)
@@ -20,7 +20,10 @@ static void perf_bpf_filter_error(struct list_head *expr __maybe_unused,
 %union
 {
        unsigned long num;
-       unsigned long sample;
+       struct {
+               unsigned long type;
+               int part;
+       } sample;
        enum perf_bpf_filter_op op;
        struct perf_bpf_filter_expr *expr;
 }
@@ -48,7 +51,7 @@ filter_term
 filter_term:
 BFT_SAMPLE BFT_OP BFT_NUM
 {
-       $$ = perf_bpf_filter_expr__new($1, $2, $3);
+       $$ = perf_bpf_filter_expr__new($1.type, $1.part, $2, $3);
 }
 
 %%
index 862060b..6b9fd55 100644 (file)
@@ -17,7 +17,8 @@ enum perf_bpf_filter_op {
 /* BPF map entry for filtering */
 struct perf_bpf_filter_entry {
        enum perf_bpf_filter_op op;
-       __u64 flags;
+       __u32 part; /* sub-sample type info when it has multiple values */
+       __u64 flags; /* perf sample type flags */
        __u64 value;
 };
 
index c072562..dddf38c 100644 (file)
@@ -40,7 +40,10 @@ static inline __u64 perf_get_sample(struct bpf_perf_event_data_kern *kctx,
        case PERF_SAMPLE_ID:
                return kctx->data->id;
        case PERF_SAMPLE_TID:
-               return kctx->data->tid_entry.tid;
+               if (entry->part)
+                       return kctx->data->tid_entry.pid;
+               else
+                       return kctx->data->tid_entry.tid;
        case PERF_SAMPLE_CPU:
                return kctx->data->cpu_entry.cpu;
        case PERF_SAMPLE_TIME: