Re: [PATCH 3/4] perf tools: Add printing perf_event_attr->type symbol in perf_event_attr__fprintf()
From: Yang Jihong
Date: Thu May 11 2023 - 03:42:18 EST
Hello,
On 2023/5/10 23:51, Adrian Hunter wrote:
On 10/05/23 11:32, Adrian Hunter wrote:
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);
}
Although it is really the repeated snprintf that seems unnecessary
so maybe use a switch but just to get the stringified name.
Ok, will use switch/case to get stringified name for type and id in v2.
Thanks,
Yang