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authorYonghong Song <yhs@fb.com>2020-11-18 23:30:39 -0800
committerDaniel Borkmann <daniel@iogearbox.net>2020-11-20 15:50:38 +0100
commit450d060e8f752a6ce052a2bffd3f01633472e330 (patch)
treeb23f99d32b48d538b2d835bf7185b21067a34ec1 /tools/bpf
parent4e99d115d865d45e17e83478d757b58d8fa66d3c (diff)
downloadlinux-450d060e8f752a6ce052a2bffd3f01633472e330.tar.gz
bpftool: Add {i,d}tlb_misses support for bpftool profile
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.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201119073039.4060095-1-yhs@fb.com
Diffstat (limited to 'tools/bpf')
-rw-r--r--tools/bpf/bpftool/prog.c30
1 files changed, 29 insertions, 1 deletions
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c
index acdb2c245f0a..1fe3ba255bad 100644
--- a/tools/bpf/bpftool/prog.c
+++ b/tools/bpf/bpftool/prog.c
@@ -1717,6 +1717,34 @@ 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;
@@ -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]);