From 4441fca0a27f5f0e2c652584ae9d7abec6255c1f Mon Sep 17 00:00:00 2001 From: Yury Norov Date: Fri, 17 Nov 2017 15:28:31 -0800 Subject: lib: test module for find_*_bit() functions find_bit functions are widely used in the kernel, including hot paths. This module tests performance of those functions in 2 typical scenarios: randomly filled bitmap with relatively equal distribution of set and cleared bits, and sparse bitmap which has 1 set bit for 500 cleared bits. On ThunderX machine: Start testing find_bit() with random-filled bitmap find_next_bit: 240043 cycles, 164062 iterations find_next_zero_bit: 312848 cycles, 163619 iterations find_last_bit: 193748 cycles, 164062 iterations find_first_bit: 177720874 cycles, 164062 iterations Start testing find_bit() with sparse bitmap find_next_bit: 3633 cycles, 656 iterations find_next_zero_bit: 620399 cycles, 327025 iterations find_last_bit: 3038 cycles, 656 iterations find_first_bit: 691407 cycles, 656 iterations [arnd@arndb.de: use correct format string for find-bit tests] Link: http://lkml.kernel.org/r/20171113135605.3166307-1-arnd@arndb.de Link: http://lkml.kernel.org/r/20171109140714.13168-1-ynorov@caviumnetworks.com Signed-off-by: Yury Norov Signed-off-by: Arnd Bergmann Reviewed-by: Clement Courbet Cc: Alexey Dobriyan Cc: Matthew Wilcox Cc: Rasmus Villemoes Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/Makefile | 1 + 1 file changed, 1 insertion(+) (limited to 'lib/Makefile') diff --git a/lib/Makefile b/lib/Makefile index e3cb2a241338..d11c48ec8ffd 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -47,6 +47,7 @@ obj-y += hexdump.o obj-$(CONFIG_TEST_HEXDUMP) += test_hexdump.o obj-y += kstrtox.o obj-$(CONFIG_TEST_BPF) += test_bpf.o +obj-$(CONFIG_TEST_FIND_BIT) += test_find_bit.o obj-$(CONFIG_TEST_FIRMWARE) += test_firmware.o obj-$(CONFIG_TEST_SYSCTL) += test_sysctl.o obj-$(CONFIG_TEST_HASH) += test_hash.o test_siphash.o -- cgit v1.2.3