Re: [PATCH V7 6/8] perf/tools: Extend branch type classification
From: Arnaldo Carvalho de Melo
Date: Tue Aug 30 2022 - 17:11:56 EST
Em Wed, Aug 24, 2022 at 10:18:20AM +0530, Anshuman Khandual escreveu:
> This updates the perf tool with generic branch type classification with new
> ABI extender place holder i.e PERF_BR_EXTEND_ABI, the new 4 bit branch type
> field i.e perf_branch_entry.new_type, new generic page fault related branch
> types and some arch specific branch types as added earlier in the kernel.
>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>
> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
> Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
> Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
> Cc: linux-perf-users@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Signed-off-by: Anshuman Khandual <anshuman.khandual@xxxxxxx>
> ---
> tools/include/uapi/linux/perf_event.h | 16 ++++++++-
> tools/perf/builtin-script.c | 2 +-
> tools/perf/util/branch.c | 52 ++++++++++++++++++++++++++-
> tools/perf/util/branch.h | 6 +++-
> tools/perf/util/session.c | 2 +-
> 5 files changed, 73 insertions(+), 5 deletions(-)
>
> diff --git a/tools/include/uapi/linux/perf_event.h b/tools/include/uapi/linux/perf_event.h
> index 146c137ff0c1..0f7c7ce29899 100644
> --- a/tools/include/uapi/linux/perf_event.h
> +++ b/tools/include/uapi/linux/perf_event.h
> @@ -255,9 +255,22 @@ enum {
> PERF_BR_IRQ = 12, /* irq */
> PERF_BR_SERROR = 13, /* system error */
> PERF_BR_NO_TX = 14, /* not in transaction */
> + PERF_BR_EXTEND_ABI = 15, /* extend ABI */
> PERF_BR_MAX,
> };
>
> +enum {
> + PERF_BR_NEW_FAULT_ALGN = 0, /* Alignment fault */
> + PERF_BR_NEW_FAULT_DATA = 1, /* Data fault */
> + PERF_BR_NEW_FAULT_INST = 2, /* Inst fault */
> + PERF_BR_NEW_ARCH_1 = 3, /* Architecture specific */
> + PERF_BR_NEW_ARCH_2 = 4, /* Architecture specific */
> + PERF_BR_NEW_ARCH_3 = 5, /* Architecture specific */
> + PERF_BR_NEW_ARCH_4 = 6, /* Architecture specific */
> + PERF_BR_NEW_ARCH_5 = 7, /* Architecture specific */
> + PERF_BR_NEW_MAX,
> +};
> +
> #define PERF_SAMPLE_BRANCH_PLM_ALL \
> (PERF_SAMPLE_BRANCH_USER|\
> PERF_SAMPLE_BRANCH_KERNEL|\
> @@ -1375,7 +1388,8 @@ struct perf_branch_entry {
> abort:1, /* transaction abort */
> cycles:16, /* cycle count to last branch */
> type:4, /* branch type */
> - reserved:40;
> + new_type:4, /* additional branch type */
> + reserved:36;
> };
>
> union perf_sample_weight {
> diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
> index 13580a9c50b8..585171479876 100644
> --- a/tools/perf/builtin-script.c
> +++ b/tools/perf/builtin-script.c
> @@ -877,7 +877,7 @@ static int print_bstack_flags(FILE *fp, struct branch_entry *br)
> br->flags.in_tx ? 'X' : '-',
> br->flags.abort ? 'A' : '-',
> br->flags.cycles,
> - br->flags.type ? branch_type_name(br->flags.type) : "-");
> + get_branch_type(br));
> }
>
> static int perf_sample__fprintf_brstack(struct perf_sample *sample,
> diff --git a/tools/perf/util/branch.c b/tools/perf/util/branch.c
> index abc673347bee..6d962b0a4532 100644
> --- a/tools/perf/util/branch.c
> +++ b/tools/perf/util/branch.c
> @@ -21,7 +21,10 @@ void branch_type_count(struct branch_type_stat *st, struct branch_flags *flags,
> if (flags->type == PERF_BR_UNKNOWN || from == 0)
> return;
>
> - st->counts[flags->type]++;
> + if (flags->type == PERF_BR_EXTEND_ABI)
> + st->new_counts[flags->new_type]++;
> + else
> + st->counts[flags->type]++;
>
> if (flags->type == PERF_BR_COND) {
> if (to > from)
> @@ -36,6 +39,25 @@ void branch_type_count(struct branch_type_stat *st, struct branch_flags *flags,
> st->cross_4k++;
> }
>
> +const char *branch_new_type_name(int new_type)
> +{
> + const char *branch_new_names[PERF_BR_NEW_MAX] = {
> + "FAULT_ALGN",
> + "FAULT_DATA",
> + "FAULT_INST",
> + "ARCH_1",
> + "ARCH_2",
> + "ARCH_3",
> + "ARCH_4",
> + "ARCH_5"
> + };
> +
> + if (new_type >= 0 && new_type < PERF_BR_NEW_MAX)
> + return branch_new_names[new_type];
> +
> + return NULL;
> +}
> +
> const char *branch_type_name(int type)
> {
> const char *branch_names[PERF_BR_MAX] = {
> @@ -62,6 +84,17 @@ const char *branch_type_name(int type)
> return NULL;
> }
>
> +const char *get_branch_type(struct branch_entry *e)
> +{
> + if (e->flags.type == PERF_BR_UNKNOWN)
> + return "";
> +
> + if (e->flags.type == PERF_BR_EXTEND_ABI)
> + return branch_new_type_name(e->flags.new_type);
> +
> + return branch_type_name(e->flags.type);
> +}
> +
> void branch_type_stat_display(FILE *fp, struct branch_type_stat *st)
> {
> u64 total = 0;
> @@ -108,6 +141,15 @@ void branch_type_stat_display(FILE *fp, struct branch_type_stat *st)
> 100.0 *
> (double)st->counts[i] / (double)total);
> }
> +
> + for (i = 0; i < PERF_BR_NEW_MAX; i++) {
> + if (st->new_counts[i] > 0)
> + fprintf(fp, "\n%8s: %5.1f%%",
> + branch_new_type_name(i),
> + 100.0 *
> + (double)st->new_counts[i] / (double)total);
> + }
> +
Strange:
75 8.89 ubuntu:20.04-x-powerpc64el : FAIL gcc version 10.3.0 (Ubuntu 10.3.0-1ubuntu1~20.04)
inlined from 'branch_type_stat_display' at util/branch.c:152:4:
/usr/powerpc64le-linux-gnu/include/bits/stdio2.h:100:10: error: '%8s' directive argument is null [-Werror=format-overflow=]
100 | return __fprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt,
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
101 | __va_arg_pack ());
| ~~~~~~~~~~~~~~~~~
> }
>
> static int count_str_scnprintf(int idx, const char *str, char *bf, int size)
> @@ -123,6 +165,9 @@ int branch_type_str(struct branch_type_stat *st, char *bf, int size)
> for (i = 0; i < PERF_BR_MAX; i++)
> total += st->counts[i];
>
> + for (i = 0; i < PERF_BR_NEW_MAX; i++)
> + total += st->new_counts[i];
> +
> if (total == 0)
> return 0;
>
> @@ -140,6 +185,11 @@ int branch_type_str(struct branch_type_stat *st, char *bf, int size)
> printed += count_str_scnprintf(j++, branch_type_name(i), bf + printed, size - printed);
> }
>
> + for (i = 0; i < PERF_BR_NEW_MAX; i++) {
> + if (st->new_counts[i] > 0)
> + printed += count_str_scnprintf(j++, branch_new_type_name(i), bf + printed, size - printed);
> + }
> +
> if (st->cross_4k > 0)
> printed += count_str_scnprintf(j++, "CROSS_4K", bf + printed, size - printed);
>
> diff --git a/tools/perf/util/branch.h b/tools/perf/util/branch.h
> index 17b2ccc61094..8d251b35428a 100644
> --- a/tools/perf/util/branch.h
> +++ b/tools/perf/util/branch.h
> @@ -24,7 +24,8 @@ struct branch_flags {
> u64 abort:1;
> u64 cycles:16;
> u64 type:4;
> - u64 reserved:40;
> + u64 new_type:4;
> + u64 reserved:36;
> };
> };
> };
> @@ -72,6 +73,7 @@ static inline struct branch_entry *perf_sample__branch_entries(struct perf_sampl
> struct branch_type_stat {
> bool branch_to;
> u64 counts[PERF_BR_MAX];
> + u64 new_counts[PERF_BR_NEW_MAX];
> u64 cond_fwd;
> u64 cond_bwd;
> u64 cross_4k;
> @@ -82,6 +84,8 @@ void branch_type_count(struct branch_type_stat *st, struct branch_flags *flags,
> u64 from, u64 to);
>
> const char *branch_type_name(int type);
> +const char *branch_new_type_name(int new_type);
> +const char *get_branch_type(struct branch_entry *e);
> void branch_type_stat_display(FILE *fp, struct branch_type_stat *st);
> int branch_type_str(struct branch_type_stat *st, char *bf, int bfsize);
>
> diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
> index 192c9274f7ad..47d5a50e616a 100644
> --- a/tools/perf/util/session.c
> +++ b/tools/perf/util/session.c
> @@ -1180,7 +1180,7 @@ static void branch_stack__printf(struct perf_sample *sample, bool callstack)
> e->flags.abort ? "A" : " ",
> e->flags.in_tx ? "T" : " ",
> (unsigned)e->flags.reserved,
> - e->flags.type ? branch_type_name(e->flags.type) : "");
> + get_branch_type(e));
> } else {
> if (i == 0) {
> printf("..... %2"PRIu64": %016" PRIx64 "\n"
> --
> 2.25.1
--
- Arnaldo