Re: [PATCH 3/4] perf tools: Add printing perf_event_attr->type symbol in perf_event_attr__fprintf()
From: Adrian Hunter
Date: Wed May 10 2023 - 04:33:53 EST
On 19/04/23 15:29, Yang Jihong wrote:
> When printing perf_event_attr, always display attr->type and its symbol
> to improve the readability of debugging information.
>
> Before:
>
> # perf --debug verbose=2 record -e cycles,cpu-clock,sched:sched_switch,branch-load-misses,r101 -C 0 true
> <SNIP>
> ------------------------------------------------------------
> perf_event_attr:
> size 136
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 6
> ------------------------------------------------------------
> perf_event_attr:
> type 1
> size 136
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 7
> ------------------------------------------------------------
> perf_event_attr:
> type 2
> size 136
> config 0x131
> { sample_period, sample_freq } 1
> sample_type IP|TID|TIME|CPU|PERIOD|RAW|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 8
> ------------------------------------------------------------
> perf_event_attr:
> type 3
> size 136
> config 0x10005
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 10
> ------------------------------------------------------------
> perf_event_attr:
> type 4
> size 136
> config 0x101
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 11
> <SNIP>
>
> After:
>
> # perf --debug verbose=2 record -e cycles,cpu-clock,sched:sched_switch,branch-load-misses,r101 -C 0 true
> <SNIP>
> ------------------------------------------------------------
> perf_event_attr:
> type 0 (PERF_TYPE_HARDWARE)
> size 136
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 6
> ------------------------------------------------------------
> perf_event_attr:
> type 1 (PERF_TYPE_SOFTWARE)
> size 136
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 7
> ------------------------------------------------------------
> perf_event_attr:
> type 2 (PERF_TYPE_TRACEPOINT)
> size 136
> config 0x131
> { sample_period, sample_freq } 1
> sample_type IP|TID|TIME|CPU|PERIOD|RAW|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 8
> ------------------------------------------------------------
> perf_event_attr:
> type 3 (PERF_TYPE_HW_CACHE)
> size 136
> config 0x10005
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 10
> ------------------------------------------------------------
> perf_event_attr:
> type 4 (PERF_TYPE_RAW)
> size 136
> config 0x101
> { sample_period, sample_freq } 4000
> sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
> read_format ID
> disabled 1
> inherit 1
> freq 1
> sample_id_all 1
> exclude_guest 1
> ------------------------------------------------------------
> sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 11
> <SNIP>
>
> Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
> ---
> tools/perf/util/perf_event_attr_fprintf.c | 24 ++++++++++++++++++++++-
> 1 file changed, 23 insertions(+), 1 deletion(-)
>
> diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
> index 433029c6afc5..d9d70126d505 100644
> --- a/tools/perf/util/perf_event_attr_fprintf.c
> +++ b/tools/perf/util/perf_event_attr_fprintf.c
> @@ -71,6 +71,27 @@ static void __p_read_format(char *buf, size_t size, u64 value)
> __p_bits(buf, size, value, bits);
> }
>
> +static void __p_type_id(char *buf, size_t size, u64 value)
> +{
> + /* sync with enum perf_type_id in perf_event.h */
> + switch (value) {
> +#define PRINT_ENUM_PERF_TYPE_ID_CASE(x) \
> + case x: \
> + snprintf(buf, size, "%"PRIu64" (%s)", value, #x); \
> + return;
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_HARDWARE)
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_SOFTWARE)
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_TRACEPOINT)
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_HW_CACHE)
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_RAW)
> + PRINT_ENUM_PERF_TYPE_ID_CASE(PERF_TYPE_BREAKPOINT)
> +#undef PRINT_ENUM_PERF_TYPE_ID_CASE
These are ABI constants so maybe simpler:
const char *fixed_types[] = {"HARDWARE", "SOFTWARE", "TRACEPOINT",
"HW_CACHE", "RAW", "BREAKPOINT"};
if (value < ARRAY_SIZE(fixed_types)) {
snprintf(buf, size, "%"PRIu64" (PERF_TYPE_%s)",
value, fixed_types[value]);
} else {
snprintf(buf, size, "%"PRIu64, value);
}
> + default:
> + snprintf(buf, size, "%"PRIu64, value);
> + return;
> + }
> +}
> +
> #define BUF_SIZE 1024
>
> #define p_hex(val) snprintf(buf, BUF_SIZE, "%#"PRIx64, (uint64_t)(val))
> @@ -79,6 +100,7 @@ static void __p_read_format(char *buf, size_t size, u64 value)
> #define p_sample_type(val) __p_sample_type(buf, BUF_SIZE, val)
> #define p_branch_sample_type(val) __p_branch_sample_type(buf, BUF_SIZE, val)
> #define p_read_format(val) __p_read_format(buf, BUF_SIZE, val)
> +#define p_type_id(val) __p_type_id(buf, BUF_SIZE, val)
>
> #define PRINT_ATTRn(_n, _f, _p, _a) \
> do { \
> @@ -96,7 +118,7 @@ int perf_event_attr__fprintf(FILE *fp, struct perf_event_attr *attr,
> char buf[BUF_SIZE];
> int ret = 0;
>
> - PRINT_ATTRf(type, p_unsigned);
> + PRINT_ATTRn("type", type, p_type_id, true);
> PRINT_ATTRf(size, p_unsigned);
> PRINT_ATTRf(config, p_hex);
> PRINT_ATTRn("{ sample_period, sample_freq }", sample_period, p_unsigned, false);