Commit 6df2eb45 authored by Andrii Nakryiko's avatar Andrii Nakryiko Committed by Alexei Starovoitov
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selftests/bpf: avoid reporting +100% difference in veristat for actual 0% 



In special case when both base and comparison values are 0, veristat
currently reports "+0 (+100%)" difference, which is quite confusing. Fix
it up to be "+0 (+0%)".

Signed-off-by: default avatarAndrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20221005161450.1064469-2-andrii@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent 2a72f595

tools/testing/selftests/bpf/veristat.c

+8 −4
Original line number Diff line number Diff line
@@ -1104,17 +1104,21 @@ static void output_comp_stats(const struct verif_stats *base, const struct verif 
			else

				snprintf(diff_buf, sizeof(diff_buf), "%s", "MISMATCH");

		} else {

			double p = 0.0;



			snprintf(base_buf, sizeof(base_buf), "%ld", base_val);

			snprintf(comp_buf, sizeof(comp_buf), "%ld", comp_val);



			diff_val = comp_val - base_val;

			if (base == &fallback_stats || comp == &fallback_stats || base_val == 0) {

				snprintf(diff_buf, sizeof(diff_buf), "%+ld (%+.2lf%%)",

					 diff_val, comp_val < base_val ? -100.0 : 100.0);

				if (comp_val == base_val)

					p = 0.0; /* avoid +0 (+100%) case */

				else

					p = comp_val < base_val ? -100.0 : 100.0;

			} else {

				snprintf(diff_buf, sizeof(diff_buf), "%+ld (%+.2lf%%)",

					 diff_val, diff_val * 100.0 / base_val);

				 p = diff_val * 100.0 / base_val;

			}

			snprintf(diff_buf, sizeof(diff_buf), "%+ld (%+.2lf%%)", diff_val, p);

		}



		switch (fmt) {