05 Jun, 2019
1 commit
-
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of version 2 of the gnu general public license as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more detailsextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 64 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Alexios Zavras
Reviewed-by: Allison Randal
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190529141901.894819585@linutronix.de
Signed-off-by: Greg Kroah-Hartman
05 Jan, 2019
1 commit
-
Contrary to other tests, test_find_next_and_bit() test uses tab
formatting in output and get_cycles() instead of ktime_get().
get_cycles() is not supported by some arches, so ktime_get() fits better
in generic code.Fix it and minor style issues, so the output looks like this:
Start testing find_bit() with random-filled bitmap
find_next_bit: 7142816 ns, 163282 iterations
find_next_zero_bit: 8545712 ns, 164399 iterations
find_last_bit: 6332032 ns, 163282 iterations
find_first_bit: 20509424 ns, 16606 iterations
find_next_and_bit: 4060016 ns, 73424 iterationsStart testing find_bit() with sparse bitmap
find_next_bit: 55984 ns, 656 iterations
find_next_zero_bit: 19197536 ns, 327025 iterations
find_last_bit: 65088 ns, 656 iterations
find_first_bit: 5923712 ns, 656 iterations
find_next_and_bit: 29088 ns, 1 iterationsLink: http://lkml.kernel.org/r/20181123174803.10916-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov
Reviewed-by: Andrew Morton
Cc: "Norov, Yuri"
Cc: Clement Courbet
Cc: Geert Uytterhoeven
Cc: Alexey Dobriyan
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 May, 2018
1 commit
-
test_find_first_bit() is intentionally sub-optimal, and may cause soft
lockup due to long time of run on some systems. So decrease length of
bitmap to traverse to avoid lockup.With the change below, time of test execution doesn't exceed 0.2 seconds
on my testing system.Link: http://lkml.kernel.org/r/20180420171949.15710-1-ynorov@caviumnetworks.com
Fixes: 4441fca0a27f5 ("lib: test module for find_*_bit() functions")
Signed-off-by: Yury Norov
Reviewed-by: Andrew Morton
Reported-by: Fengguang Wu
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Feb, 2018
3 commits
-
We've measured that we spend ~0.6% of sys cpu time in cpumask_next_and().
It's essentially a joined iteration in search for a non-zero bit, which is
currently implemented as a lookup join (find a nonzero bit on the lhs,
lookup the rhs to see if it's set there).Implement a direct join (find a nonzero bit on the incrementally built
join). Also add generic bitmap benchmarks in the new `test_find_bit`
module for new function (see `find_next_and_bit` in [2] and [3] below).For cpumask_next_and, direct benchmarking shows that it's 1.17x to 14x
faster with a geometric mean of 2.1 on 32 CPUs [1]. No impact on memory
usage. Note that on Arm, the new pure-C implementation still outperforms
the old one that uses a mix of C and asm (`find_next_bit`) [3].[1] Approximate benchmark code:
```
unsigned long src1p[nr_cpumask_longs] = {pattern1};
unsigned long src2p[nr_cpumask_longs] = {pattern2};
for (/*a bunch of repetitions*/) {
for (int n = -1; n ]
Link: http://lkml.kernel.org/r/1512556816-28627-1-git-send-email-geert@linux-m68k.org
Link: http://lkml.kernel.org/r/20171128131334.23491-1-courbet@google.com
Signed-off-by: Clement Courbet
Signed-off-by: Geert Uytterhoeven
Cc: Yury Norov
Cc: Geert Uytterhoeven
Cc: Alexey Dobriyan
Cc: Rasmus Villemoes
Signed-off-by: Andrew MortonSigned-off-by: Linus Torvalds
-
As suggested in review comments:
* printk: align numbers using whitespaces instead of tabs;
* return error value from init() to avoid calling rmmod if testing again;
* use ktime_get instead of get_cycles as some arches don't support it;The output in dmesg (on QEMU arm64):
[ 38.823430] Start testing find_bit() with random-filled bitmap
[ 38.845358] find_next_bit: 20138448 ns, 163968 iterations
[ 38.856217] find_next_zero_bit: 10615328 ns, 163713 iterations
[ 38.863564] find_last_bit: 7111888 ns, 163967 iterations
[ 40.944796] find_first_bit: 2081007216 ns, 163968 iterations
[ 40.944975]
[ 40.944975] Start testing find_bit() with sparse bitmap
[ 40.945268] find_next_bit: 73216 ns, 656 iterations
[ 40.967858] find_next_zero_bit: 22461008 ns, 327025 iterations
[ 40.968047] find_last_bit: 62320 ns, 656 iterations
[ 40.978060] find_first_bit: 9889360 ns, 656 iterationsLink: http://lkml.kernel.org/r/20171124143040.a44jvhmnaiyedg2i@yury-thinkpad
Signed-off-by: Yury Norov
Tested-by: Geert Uytterhoeven
Cc: Alexey Dobriyan
Cc: Clement Courbet
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As suggested in review comments, rename test_find_bit.c to
find_bit_benchmark.c.Link: http://lkml.kernel.org/r/20171124143040.a44jvhmnaiyedg2i@yury-thinkpad
Signed-off-by: Yury Norov
Tested-by: Geert Uytterhoeven
Cc: Alexey Dobriyan
Cc: Clement Courbet
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
