From ecb8bd70d51ccf9009219a6097cef293deada65b Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Sun, 1 Sep 2024 19:24:03 +0200 Subject: [PATCH] selftests: vDSO: build tests with O2 optimization Without -O2, the generated code for testing chacha function is awful. GCC even implements rol32() as a function of 20 instructions instead of just using the rotlwi instruction. ~# time ./vdso_test_chacha TAP version 13 1..1 ok 1 chacha: PASS real 0m 37.16s user 0m 36.89s sys 0m 0.26s Several other selftests directory add -O2, and the kernel is also always built with optimisation active. Do the same for vDSO selftests. With this patch the time is reduced by approximately 15%. ~# time ./vdso_test_chacha TAP version 13 1..1 ok 1 chacha: PASS real 0m 32.09s user 0m 31.86s sys 0m 0.22s Signed-off-by: Christophe Leroy Signed-off-by: Jason A. Donenfeld --- tools/testing/selftests/vDSO/Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/vDSO/Makefile b/tools/testing/selftests/vDSO/Makefile index d586d3e7a7c1..04930125035e 100644 --- a/tools/testing/selftests/vDSO/Makefile +++ b/tools/testing/selftests/vDSO/Makefile @@ -14,7 +14,7 @@ TEST_GEN_PROGS += vdso_test_getrandom TEST_GEN_PROGS += vdso_test_chacha endif -CFLAGS := -std=gnu99 +CFLAGS := -std=gnu99 -O2 ifeq ($(CONFIG_X86_32),y) LDLIBS += -lgcc_s