bpftool: Add {i,d}tlb_misses support for bpftool profile (450d060e) · Commits · 戴 / test

Commit ("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

tools/bpf/bpftool/prog.c

+29 −1

Original line number	Diff line number	Diff line
		@@ -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]);

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