Re: [PATCH v2 4/4] perf tools: Add printing perf_event_attr config symbol in perf_event_attr__fprintf()

From: Yang Jihong
Date: Mon May 15 2023 - 04:52:16 EST


Hello,

On 2023/5/12 18:34, Adrian Hunter wrote:
On 11/05/23 10:51, Yang Jihong wrote:
When printing perf_event_attr, always display perf_event_attr config 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,mem:0x0 -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 = 5
------------------------------------------------------------
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 = 6
------------------------------------------------------------
perf_event_attr:
type 2
size 136
config 0x143
{ 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 = 7
------------------------------------------------------------
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 = 9
------------------------------------------------------------
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 = 10
------------------------------------------------------------
perf_event_attr:
type 5
size 136
{ sample_period, sample_freq } 1
sample_type IP|TID|TIME|CPU|IDENTIFIER
read_format ID
disabled 1
inherit 1
sample_id_all 1
exclude_guest 1
bp_type 3
{ bp_len, config2 } 0x4
------------------------------------------------------------
<SNIP>

After:

# perf --debug verbose=2 record -e cycles,cpu-clock,sched:sched_switch,branch-load-misses,r101,mem:0x0 -C 0 true
<SNIP>
------------------------------------------------------------
perf_event_attr:
type 0 (PERF_TYPE_HARDWARE)
size 136
config 0 (PERF_COUNT_HW_CPU_CYCLES)
{ 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 = 5
------------------------------------------------------------
perf_event_attr:
type 1 (PERF_TYPE_SOFTWARE)
size 136
config 0 (PERF_COUNT_SW_CPU_CLOCK)
{ 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 2 (PERF_TYPE_TRACEPOINT)
size 136
config 0x143 (sched:sched_switch)
{ 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 = 7
------------------------------------------------------------
perf_event_attr:
type 3 (PERF_TYPE_HW_CACHE)
size 136
config 0x10005 (PERF_COUNT_HW_CACHE_RESULT_MISS | PERF_COUNT_HW_CACHE_OP_READ | PERF_COUNT_HW_CACHE_BPU)
{ 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 = 9
------------------------------------------------------------
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 = 10
------------------------------------------------------------
perf_event_attr:
type 5 (PERF_TYPE_BREAKPOINT)
size 136
config 0
{ sample_period, sample_freq } 1
sample_type IP|TID|TIME|CPU|IDENTIFIER
read_format ID
disabled 1
inherit 1
sample_id_all 1
exclude_guest 1
bp_type 3
{ bp_len, config2 } 0x4
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 11
------------------------------------------------------------
perf_event_attr:
type 1 (PERF_TYPE_SOFTWARE)
size 136
config 9 (PERF_COUNT_SW_DUMMY)
{ sample_period, sample_freq } 4000
sample_type IP|TID|TIME|CPU|PERIOD|IDENTIFIER
read_format ID
inherit 1
mmap 1
comm 1
freq 1
task 1
sample_id_all 1
mmap2 1
comm_exec 1
ksymbol 1
bpf_event 1
------------------------------------------------------------
sys_perf_event_open: pid -1 cpu 0 group_fd -1 flags 0x8 = 12
<SNIP>

Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
---
tools/perf/util/perf_event_attr_fprintf.c | 159 +++++++++++++++++++++-
1 file changed, 158 insertions(+), 1 deletion(-)

diff --git a/tools/perf/util/perf_event_attr_fprintf.c b/tools/perf/util/perf_event_attr_fprintf.c
index cd0905d8cb7a..7730f0d7c28a 100644
--- a/tools/perf/util/perf_event_attr_fprintf.c
+++ b/tools/perf/util/perf_event_attr_fprintf.c
@@ -7,6 +7,11 @@
#include <linux/perf_event.h>
#include "util/evsel_fprintf.h"
+#ifdef HAVE_LIBTRACEEVENT
+#include <stdlib.h> // for free

stdlib has too much ordinary stuff for the "// for free" comment
to be interesting, and it is very unlikely to be updated if another
dependency on stdlib were added.

+#include "trace-event.h"
+#endif

No where else is "#ifdef HAVE_LIBTRACEEVENT" put around
"#include "trace-event.h"

OK, will remove "// for free" and "#ifdef HAVE_LIBTRACEEVENT" in v3.
+
struct bit_names {
int bit;
const char *name;
@@ -86,6 +91,85 @@ static const char *stringify_perf_type_id(u64 value)
return NULL;
}
}
+
+static const char *stringify_perf_hw_id(u64 value)
+{
+ /* sync with enum perf_hw_id in perf_event.h */

As with patch 3, this comment and same ones below could be left out
OK, will remove in v3.

+ switch (value) {
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CPU_CYCLES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_INSTRUCTIONS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_REFERENCES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_MISSES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_BRANCH_INSTRUCTIONS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_BRANCH_MISSES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_BUS_CYCLES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_STALLED_CYCLES_FRONTEND)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_STALLED_CYCLES_BACKEND)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_REF_CPU_CYCLES)
+ default:
+ return NULL;
+ }
+}
+
+static const char *stringify_perf_hw_cache_id(u64 value)
+{
+ /* sync with enum perf_hw_cache_id in perf_event.h */
+ switch (value) {
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_L1D)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_L1I)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_LL)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_DTLB)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_ITLB)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_BPU)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_NODE)
+ default:
+ return NULL;
+ }
+}
+
+static const char *stringify_perf_hw_cache_op_id(u64 value)
+{
+ /* sync with enum perf_hw_cache_op_id in perf_event.h */
+ switch (value) {
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_OP_READ)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_OP_WRITE)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_OP_PREFETCH)
+ default:
+ return NULL;
+ }
+}
+
+static const char *stringify_perf_hw_cache_op_result_id(u64 value)
+{
+ /* sync with enum perf_hw_cache_op_result_id in perf_event.h */
+ switch (value) {
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_RESULT_ACCESS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_HW_CACHE_RESULT_MISS)
+ default:
+ return NULL;
+ }
+}
+
+static const char *stringify_perf_sw_id(u64 value)
+{
+ /* sync with enum perf_sw_ids in perf_event.h */
+ switch (value) {
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_CPU_CLOCK)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_TASK_CLOCK)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_PAGE_FAULTS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_CONTEXT_SWITCHES)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_CPU_MIGRATIONS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_PAGE_FAULTS_MIN)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_PAGE_FAULTS_MAJ)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_ALIGNMENT_FAULTS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_EMULATION_FAULTS)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_DUMMY)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_BPF_OUTPUT)
+ ENUM_ID_TO_STR_CASE(PERF_COUNT_SW_CGROUP_SWITCHES)
+ default:
+ return NULL;
+ }
+}
#undef ENUM_ID_TO_STR_CASE
static void __p_type_id(char *buf, size_t size, u64 value)
@@ -98,6 +182,78 @@ static void __p_type_id(char *buf, size_t size, u64 value)
snprintf(buf, size, "%"PRIu64" (%s)", value, str);
}
+static void __p_config_hw_id(char *buf, size_t size, u64 value)
+{
+ const char *str = stringify_perf_hw_id(value);
+
+ if (str == NULL)
+ snprintf(buf, size, "%"PRIx64, value);
+ else
+ snprintf(buf, size, "%"PRIx64" (%s)", value, str);

This could use the print_id() or equivalent helper mentioned in patch 3
OK, will fix in v3.

+}
+
+static void __p_config_sw_id(char *buf, size_t size, u64 value)
+{
+ const char *str = stringify_perf_sw_id(value);
+
+ if (str == NULL)
+ snprintf(buf, size, "%"PRIx64, value);
+ else
+ snprintf(buf, size, "%"PRIx64" (%s)", value, str);

Ditto
OK, ditto

+}
+
+static void __p_config_hw_cache_id(char *buf, size_t size, u64 value)
+{
+ const char *hw_cache_str = stringify_perf_hw_cache_id(value & 0xff);
+ const char *hw_cache_op_str =
+ stringify_perf_hw_cache_op_id((value & 0xff00) >> 8);
+ const char *hw_cache_op_result_str =
+ stringify_perf_hw_cache_op_result_id((value & 0xff0000) >> 16);
+
+ if (hw_cache_str == NULL || hw_cache_op_str == NULL ||
+ hw_cache_op_result_str == NULL) {
+ snprintf(buf, size, "%#"PRIx64, value);
+ } else {
+ snprintf(buf, size, "%#"PRIx64" (%s | %s | %s)", value,
+ hw_cache_op_result_str, hw_cache_op_str, hw_cache_str);
+ }
+}
+
+#ifdef HAVE_LIBTRACEEVENT
+static void __p_config_tracepoint_id(char *buf, size_t size, u64 value)
+{
+ char *str = tracepoint_id_to_name(value);
+
+ if (str != NULL) {
+ snprintf(buf, size, "%#"PRIx64" (%s)", value, str);
+ free(str);
+ } else {
+ snprintf(buf, size, "%#"PRIx64, value);
+ }

Ditto


Note, can just call free() on 'str' whether or not it is NULL.

OK, ditto

Thanks for such a detailed suggestion.

Thanks,
Yang