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| author | Yury Norov <ynorov@caviumnetworks.com> | 2017-11-17 15:28:31 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-11-17 16:10:02 -0800 |
| commit | 4441fca0a27f5f0e2c652584ae9d7abec6255c1f (patch) | |
| tree | ba8583bfe222c45b3f34a98f2d633b22ca3530f1 /lib/Kconfig.debug | |
| parent | 0b548e33e6cb2bff240fdaf1783783be15c29080 (diff) | |
| download | lwn-4441fca0a27f5f0e2c652584ae9d7abec6255c1f.tar.gz lwn-4441fca0a27f5f0e2c652584ae9d7abec6255c1f.zip | |
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')
| -rw-r--r-- | lib/Kconfig.debug | 9 |
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. +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 |