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/Kconfig.debug | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'lib/Kconfig.debug') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 8ffd891857ab..ce813731269f 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1850,6 +1850,15 @@ config TEST_BPF If unsure, say N. +config TEST_FIND_BIT + tristate "Test find_bit functions" + default n + help + This builds the "test_find_bit" module that measure find_*_bit() + functions performance. + + If unsure, say N. + config TEST_FIRMWARE tristate "Test firmware loading via userspace interface" default n -- cgit v1.2.3-70-g09d2