[PATCH 2/2] perf script: Support instruction latency

From: kan . liang
Date: Wed Sep 29 2021 - 11:43:04 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The instruction latency information can be recorded on
some platforms, e.g., the Intel Sapphire Rapids server. With both memory
latency (weight) and the new instruction latency information, users can
easily locate the expensive load instructions, and also understand the time
spent in different stages. The users can optimize their applications in
different pipeline stages.

Add a new field "ins_lat" to filter the instruction latency information,
which is available with sample type PERF_SAMPLE_WEIGHT_STRUCT.

Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
---
tools/perf/Documentation/perf-script.txt | 2 +-
tools/perf/builtin-script.c | 14 ++++++++++++--
2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/tools/perf/Documentation/perf-script.txt b/tools/perf/Documentation/perf-script.txt
index c805152..b007071 100644
--- a/tools/perf/Documentation/perf-script.txt
+++ b/tools/perf/Documentation/perf-script.txt
@@ -130,7 +130,7 @@ OPTIONS
comm, tid, pid, time, cpu, event, trace, ip, sym, dso, addr, symoff,
srcline, period, iregs, uregs, brstack, brstacksym, flags, bpf-output,
brstackinsn, brstackoff, callindent, insn, insnlen, synth, phys_addr,
- metric, misc, srccode, ipc, data_page_size, code_page_size.
+ metric, misc, srccode, ipc, data_page_size, code_page_size, ins_lat.
Field list can be prepended with the type, trace, sw or hw,
to indicate to which event type the field list applies.
e.g., -F sw:comm,tid,time,ip,sym and -F trace:time,cpu,trace
diff --git a/tools/perf/builtin-script.c b/tools/perf/builtin-script.c
index 9f62ac6..4ac47e3 100644
--- a/tools/perf/builtin-script.c
+++ b/tools/perf/builtin-script.c
@@ -122,6 +122,7 @@ enum perf_output_field {
PERF_OUTPUT_TOD = 1ULL << 32,
PERF_OUTPUT_DATA_PAGE_SIZE = 1ULL << 33,
PERF_OUTPUT_CODE_PAGE_SIZE = 1ULL << 34,
+ PERF_OUTPUT_INS_LAT = 1ULL << 35,
};

struct perf_script {
@@ -188,6 +189,7 @@ struct output_option {
{.str = "tod", .field = PERF_OUTPUT_TOD},
{.str = "data_page_size", .field = PERF_OUTPUT_DATA_PAGE_SIZE},
{.str = "code_page_size", .field = PERF_OUTPUT_CODE_PAGE_SIZE},
+ {.str = "ins_lat", .field = PERF_OUTPUT_INS_LAT},
};

enum {
@@ -262,7 +264,8 @@ static struct {
PERF_OUTPUT_DSO | PERF_OUTPUT_PERIOD |
PERF_OUTPUT_ADDR | PERF_OUTPUT_DATA_SRC |
PERF_OUTPUT_WEIGHT | PERF_OUTPUT_PHYS_ADDR |
- PERF_OUTPUT_DATA_PAGE_SIZE | PERF_OUTPUT_CODE_PAGE_SIZE,
+ PERF_OUTPUT_DATA_PAGE_SIZE | PERF_OUTPUT_CODE_PAGE_SIZE |
+ PERF_OUTPUT_INS_LAT,

.invalid_fields = PERF_OUTPUT_TRACE | PERF_OUTPUT_BPF_OUTPUT,
},
@@ -522,6 +525,10 @@ static int evsel__check_attr(struct evsel *evsel, struct perf_session *session)
evsel__check_stype(evsel, PERF_SAMPLE_CODE_PAGE_SIZE, "CODE_PAGE_SIZE", PERF_OUTPUT_CODE_PAGE_SIZE))
return -EINVAL;

+ if (PRINT_FIELD(INS_LAT) &&
+ evsel__check_stype(evsel, PERF_SAMPLE_WEIGHT_STRUCT, "WEIGHT_STRUCT", PERF_OUTPUT_INS_LAT))
+ return -EINVAL;
+
return 0;
}

@@ -2039,6 +2046,9 @@ static void process_event(struct perf_script *script,
if (PRINT_FIELD(WEIGHT))
fprintf(fp, "%16" PRIu64, sample->weight);

+ if (PRINT_FIELD(INS_LAT))
+ fprintf(fp, "%16" PRIu16, sample->ins_lat);
+
if (PRINT_FIELD(IP)) {
struct callchain_cursor *cursor = NULL;

@@ -3715,7 +3725,7 @@ int cmd_script(int argc, const char **argv)
"addr,symoff,srcline,period,iregs,uregs,brstack,"
"brstacksym,flags,bpf-output,brstackinsn,brstackoff,"
"callindent,insn,insnlen,synth,phys_addr,metric,misc,ipc,tod,"
- "data_page_size,code_page_size",
+ "data_page_size,code_page_size,ins_lat",
parse_output_fields),
OPT_BOOLEAN('a', "all-cpus", &system_wide,
"system-wide collection from all CPUs"),
--
2.7.4