path: root/lib/Kconfig.debug
diff options
authorYury Norov <ynorov@caviumnetworks.com>2017-11-17 15:28:31 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-11-17 16:10:02 -0800
commit4441fca0a27f5f0e2c652584ae9d7abec6255c1f (patch)
treeba8583bfe222c45b3f34a98f2d633b22ca3530f1 /lib/Kconfig.debug
parent0b548e33e6cb2bff240fdaf1783783be15c29080 (diff)
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 <ynorov@caviumnetworks.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Clement Courbet <courbet@google.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/Kconfig.debug')
1 files changed, 9 insertions, 0 deletions
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.
+ 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.
tristate "Test firmware loading via userspace interface"
default n

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