Re: [PATCH v2 3/4] perf tools: Add printing perf_event_attr type symbol in perf_event_attr__fprintf()
From: Adrian Hunter
Date: Mon May 15 2023 - 04:57:09 EST
On 15/05/23 11:48, Yang Jihong wrote:
> 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 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,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
>>> { 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
>>> { 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
>>> { 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
>>> { 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
>>> { 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>
>>>
>>> Signed-off-by: Yang Jihong <yangjihong1@xxxxxxxxxx>
>>> ---
>>> tools/perf/util/perf_event_attr_fprintf.c | 30 ++++++++++++++++++++++-
>>> 1 file changed, 29 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..cd0905d8cb7a 100644
>>> --- a/tools/perf/util/perf_event_attr_fprintf.c
>>> +++ b/tools/perf/util/perf_event_attr_fprintf.c
>>> @@ -71,6 +71,33 @@ static void __p_read_format(char *buf, size_t size, u64 value)
>>> __p_bits(buf, size, value, bits);
>>> }
>>> +#define ENUM_ID_TO_STR_CASE(x) case x: return (#x);
>>> +static const char *stringify_perf_type_id(u64 value)
>>> +{
>>> + /* sync with enum perf_type_id in perf_event.h */
>>
>> Everything in this file syncs with perf_event.h, so the comment
>> does not seem very useful.
> OK, will fix in v3.
>>
>>> + switch (value) {
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_HARDWARE)
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_SOFTWARE)
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_TRACEPOINT)
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_HW_CACHE)
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_RAW)
>>> + ENUM_ID_TO_STR_CASE(PERF_TYPE_BREAKPOINT)
>>> + default:
>>> + return NULL;
>>> + }
>>> +}
>>> +#undef ENUM_ID_TO_STR_CASE
>>> +
>>> +static void __p_type_id(char *buf, size_t size, u64 value)
>>> +{
>>> + const char *str = stringify_perf_type_id(value);
>>> +
>>> + if (str == NULL)
>>> + snprintf(buf, size, "%"PRIu64, value);
>>> + else
>>> + snprintf(buf, size, "%"PRIu64" (%s)", value, str);
>>
>> These 4 lines end up getting used again about 3 times in the next
>> patch, so might as well be a separate function e.g.
>>
>> print_id(buf, size, value, stringify_perf_type_id(value));
>>
>> where:
>>
>> static void print_id(char *buf, size_t size, u64 value, const char *str)
>> {
>> if (str == NULL)
>> snprintf(buf, size, "%"PRIu64, value);
>> else
>> snprintf(buf, size, "%"PRIu64" (%s)", value, str);
>> }
>>
> OK, will add print_id() helper in v3.
> If print_id() helper is also used to print config id, is printed in the decimal format. In the past, it is printed in the hexadecimal format，
> there may be some changes here.
>
> Before:
> config 0x143
>
> After:
> config 323 (sched:sched_switch)
Right I didn't notice the difference. Best keep print_id() just for the hex cases.
>
>>> +}
>>> +
>>> #define BUF_SIZE 1024
>>> #define p_hex(val) snprintf(buf, BUF_SIZE, "%#"PRIx64, (uint64_t)(val))
>>> @@ -79,6 +106,7 @@ 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 +124,7 @@ 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);
>>
>> .
>>