Commit 47c09d6a9f67("bpftool: Introduce "prog profile" command")
introduced "bpftool prog profile" command which can be used
to profile bpf program with metrics like # of instructions,
This patch added support for itlb_misses and dtlb_misses.
During an internal bpf program performance evaluation,
I found these two metrics are also very useful. The following
is an example output:
$ bpftool prog profile id 324 duration 3 cycles itlb_misses
1885029 run_cnt
5134686073 cycles
306893 itlb_misses
$ bpftool prog profile id 324 duration 3 cycles dtlb_misses
1827382 run_cnt
4943593648 cycles
5975636 dtlb_misses
$ bpftool prog profile id 324 duration 3 cycles llc_misses
1836527 run_cnt
5019612972 cycles
4161041 llc_misses
>From the above, we can see quite some dtlb misses, 3 dtlb misses
perf prog run. This might be something worth further investigation.
Cc: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Yonghong Song <yhs@xxxxxx>
---
tools/bpf/bpftool/prog.c | 32 ++++++++++++++++++++++++++++++--
1 file changed, 30 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index acdb2c245f0a..e33f27b950a5 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1717,11 +1717,39 @@ struct profile_metric {
.ratio_desc = "LLC misses per million insns",
.ratio_mul = 1e6,
},
+ {
+ .name = "itlb_misses",
+ .attr = {
+ .type = PERF_TYPE_HW_CACHE,
+ .config =
+ PERF_COUNT_HW_CACHE_ITLB |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+ .exclude_user = 1
+ },
+ .ratio_metric = 2,
+ .ratio_desc = "itlb misses per million insns",
+ .ratio_mul = 1e6,
+ },
+ {
+ .name = "dtlb_misses",
+ .attr = {
+ .type = PERF_TYPE_HW_CACHE,
+ .config =
+ PERF_COUNT_HW_CACHE_DTLB |
+ (PERF_COUNT_HW_CACHE_OP_READ << 8) |
+ (PERF_COUNT_HW_CACHE_RESULT_MISS << 16),
+ .exclude_user = 1
+ },
+ .ratio_metric = 2,
+ .ratio_desc = "dtlb misses per million insns",
+ .ratio_mul = 1e6,
+ },
};
static __u64 profile_total_count;
-#define MAX_NUM_PROFILE_METRICS 4
+#define MAX_NUM_PROFILE_METRICS 6
static int profile_parse_metrics(int argc, char **argv)
{
@@ -2109,7 +2137,7 @@ static int do_help(int argc, char **argv)
" struct_ops | fentry | fexit | freplace | sk_lookup }\n"
" ATTACH_TYPE := { msg_verdict | stream_verdict | stream_parser |\n"
" flow_dissector }\n"
- " METRIC := { cycles | instructions | l1d_loads | llc_misses }\n"
+ " METRIC := { cycles | instructions | l1d_loads | llc_misses | itlb_misses | dtlb_misses }\n"
" " HELP_SPEC_OPTIONS "\n"
"",
bin_name, argv[-2]);
--
2.24.1
