- 17 Apr, 2015 40 commits
-
-
Uwe Kleine-König authored
The rtc's status register allows to determine if a 32k crystal is connected to keep the rtc running in low power states provided the corresponding fuse bits were blown correctly during production. (In case they were not, the right frequency can be stated in the device tree.) If there is no such crystal available force the 24 MHz XTAL clock to keep running to retain the right date and time. Otherwise use the crystal to save some power. It would be nice to only switch to the crystal when the XTAL clock is about to be disabled and keep the crystal off when unneeded because XTAL is always on while the chip is powered on. But as sudden power loss isn't detectable this is not save. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Robert Kmiec authored
This commit does not change any logic here. It just makes the code easier to read. This is how it looked like: If err != 0 return err; else return 0; Signed-off-by: Robert Kmiec <robert.r.kmiec@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Andrey Ryabinin authored
It might be annoying to constantly see this: scripts/Makefile.kasan:16: Cannot use CONFIG_KASAN: -fsanitize=kernel-address is not supported by compiler while performing allmodconfig/allyesconfig build tests. Disable this warning if CONFIG_COMPILE_TEST=y. Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Rasmus Villemoes authored
sprintf() reliably returns the number of characters printed, so we don't need to ask strlen() where we are. Also replace calling sprintf("%02x") in a loop with the much simpler bin2hex(). [akpm@linux-foundation.org: it's odd to include kernel.h after everything else] Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Since commit 1f65f947 ("checkpatch: add checks for question mark and colon spacing") back in 2008, checkpatch has reported false positive for asm volatile uses of "::" checkpatch thinks colons should always have spaces around it. Add an exception for colons with colons on either side for this valid asm volatile (and c++) use. Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Yehuda Yitschak <yehuday@marvell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
If a patch touches multiple files, the --fix and --fix-inplace option doesn't keep the proper line count and makes the new patch file not able to be applied via bad offset line numbers when lines are added or deleted by the --fix option. Dunno how that extra backslash snuck in there. Signed-off-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Andy Lutomirski authored
ENOSYS is the mechanism used by user code to detect whether the running kernel implements a given system call. It should not be returned by anything except an unimplemented system call. Unfortunately, it is rather frequently used in the kernel to indicate that various new functions of existing system calls are not implemented. This should be discouraged. Improve the comment in errno.h to help clarify ENOSYS's purpose. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Andy Lutomirski authored
ENOSYS means that a nonexistent system call was called. We have a bad habit of using it for things like invalid operations on otherwise valid syscalls. We should avoid this in new code. Pervasive incorrect usage of ENOSYS came up at the kernel summit ABI review discussion. Let's see if checkpatch can help. I'll submit a separate patch for include/uapi/asm-generic/errno.h. Signed-off-by: Andy Lutomirski <luto@amacapital.net> Cc: Pavel Machek <pavel@ucw.cz> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
const objects shouldn't be __read_mostly. They are read-only. Marking these objects as __read_mostly causes section conflicts with LTO linking. So add a test to try to avoid this issue. Signed-off-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Sam Bobroff authored
Code such as: x = timercmp(&now, &end, <); Will currently trigger a checkpatch error. e.g. ERROR: spaces required around that '<' This is because the "Ignore operators passed as parameters" check looks only for a comma following the operator. Improve the check by also looking for a close parenthesis. Signed-off-by: Sam Bobroff <sam.bobroff@au1.ibm.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Add a test for sizeof(foo)/sizeof(foo[0]) that could be ARRAY_SIZE(foo). Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Add another struct to the list of normally const struct types Signed-off-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@shadowen.org> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jiri Slaby <jslaby@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
There are #defines with long string constants like: #define foo "some really long string > 80 columns" Add a long line exception for them. Miscellanea: Use the $String variable for slightly better readability Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Madalin-Cristian Bucur <madalin.bucur@freescale.com> Cc: Andy Whitcroft <apw@shadowen.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Commit messages lines are sometimes overly long. Suggest line wrapping at 75 columns so the default git commit log indentation of 4 plus the commit message text still fits on an 80 column screen. Add a checkpatch test for long commit messages lines too. Signed-off-by: Joe Perches <joe@perches.com> Cc: David Miller <davem@davemloft.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ian Morris <ipm@chirality.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Fabian Frederick authored
Currently checkpatch warns when asm/file.h is included and linux/file.h exists. That conversion can be made when linux/file.h includes asm/file.h which is not always the case.(See signal.h) Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Andy Whitcroft <apw@canonical.com> Acked-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Using 'const <type> const *' is generally meant to be written 'const <type> * const'. Add a test for the miswritten form. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Add a few conditions to the test to find return (ERRNO); Make the output message a bit less cryptic too. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Currently checkpatch will fuss if one uses world writable settings in debugfs files and DEVICE_ATTR uses by testing S_IWUGO but not testing S_IWOTH, S_IRWXUGO or S_IALLUGO. Extend the check to catch all cases exporting world writable permissions including octal values. [akpm@linux-foundation.org: remove stray $] Signed-off-by: Joe Perches <joe@perches.com> Original-patch-by: Nicholas Mc Guire <hofrat@osadl.org> Cc: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
If a codespell dictionary exists, use it if desired. default is off, maybe it could be turned on later. codespell's dictionary format allows multiple possible corrections, ignore that for now and only use the first suggestion. Also add \b to spelling test so that consecutive misspelled words are found properly. Signed-off-by: Joe Perches <joe@perches.com> Cc: Andy Whitcroft <apw@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Masanari Iida <standby24x7@gmail.com> Cc: Lucas De Marchi <lucas.de.marchi@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Jani Nikula authored
References: http://mid.gmane.org/1424977312-24902-1-git-send-email-ville.syrjala@linux.intel.comSigned-off-by: Jani Nikula <jani.nikula@intel.com> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
Only commit log and patch additions are checked for typos and spelling errors currently. Add a check of the email subject line too. Signed-off-by: Joe Perches <joe@perches.com> Suggested-by: Jani Nikula <jani.nikula@linux.intel.com> Tested-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Joe Perches authored
The "no space is necessary after a cast" sizeof exclusion doesn't work properly. The test reports a false positive for code like: BUILD_BUG_ON(sizeof(struct batadv_bla_claim_dst) != 6); Make it work, simplify the exclusions, and add some comments. Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Marek Lindner <mareklindner@neomailbox.ch> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Nicolas Iooss authored
Commit 2473238e ("ihex: add support for CS:IP/EIP records") removes the "default:" statement in the switch block, making the "return usage();" line dead code and ihex2fw silently ignoring unknown options. Restore this statement. This bug was found by building with HOSTCC=clang and adding -Wunreachable-code-return to HOSTCFLAGS. Fixes: 2473238e ("ihex: add support for CS:IP/EIP records") Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: David Woodhouse <dwmw2@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Yury Norov authored
bitmap_empty() has its own implementation. But it's clearly as simple as: find_first_bit(src, nbits) == nbits The same is true for 'bitmap_full'. Signed-off-by: Yury Norov <yury.norov@gmail.com> Cc: George Spelvin <linux@horizon.com> Cc: Alexey Klimov <klimov.linux@gmail.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>
-
Javi Merino authored
Now that the kernel provides DIV_ROUND_CLOSEST_ULL(), drop the internal implementation and use the kernel one. Signed-off-by: Javi Merino <javi.merino@arm.com> Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: Peter Rosin <peda@axentia.se> Acked-by: Mark Brown <broonie@kernel.org> Cc: Liam Girdwood <lgirdwood@gmail.com> Cc: Jaroslav Kysela <perex@perex.cz> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Javi Merino authored
Now that the kernel provides DIV_ROUND_CLOSEST_ULL(), drop the internal implementation and use the kernel one. Signed-off-by: Javi Merino <javi.merino@arm.com> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Acked-by: Antti Palosaari <crope@iki.fi> Reviewed-by: Antti Palosaari <crope@iki.fi> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Javi Merino authored
Now that the kernel provides DIV_ROUND_CLOSEST_ULL(), drop the internal implementation and use the kernel one. Signed-off-by: Javi Merino <javi.merino@arm.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Javi Merino authored
Now that the kernel provides DIV_ROUND_CLOSEST_ULL(), drop the internal implementation and use the kernel one. Signed-off-by: Javi Merino <javi.merino@arm.com> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Acked-by: Alex Elder <elder@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Javi Merino authored
We have grown a number of different implementations of DIV_ROUND_CLOSEST_ULL throughout the kernel. Move the i915 one to kernel.h so that it can be reused. Signed-off-by: Javi Merino <javi.merino@arm.com> Reviewed-by: Jeff Epler <jepler@unpythonic.net> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: David Airlie <airlied@linux.ie> Cc: Guenter Roeck <linux@roeck-us.net> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Alex Elder <elder@linaro.org> Cc: Antti Palosaari <crope@iki.fi> Cc: Javi Merino <javi.merino@arm.com> Cc: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Mike Turquette <mturquette@linaro.org> Cc: Stephen Boyd <sboyd@codeaurora.org> Cc: Stephen Hemminger <shemminger@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Rasmus Villemoes authored
I hadn't had enough coffee when I wrote this. Currently, the final increment of buf depends on the value loaded from the table, and causes gcc to emit a cmov immediately before the return. It is smarter to let it depend on r, since the increment can then be computed in parallel with the final load/store pair. It also shaves 16 bytes of .text. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Tejun Heo <tj@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Bartosz Golaszewski authored
Replace the loop iterating over pwm_freq_cksel0 with a call to find_closest_descending(). Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Bartosz Golaszewski authored
Replace RANGE_TO_REG() and FREQ_TO_REG() implementations with calls to find_closest(). Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Bartosz Golaszewski authored
Use find_closest() to locate the closest average in ina226_avg_tab. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Bartosz Golaszewski authored
Describe proper naming convention for local variables in macros resembling functions. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Bartosz Golaszewski authored
This series unduplicates the code used to find the member in an array closest to 'x'. The first patch adds a macro implementing the algorithm in two flavors - for arrays sorted in ascending and descending order. The second updates Documentation/CodingStyle on the naming convention for local variables in macros resembling functions. Other three patches replace duplicated code with calls to one of these macros in some hwmon drivers. This patch (of 5): Searching for the member of an array closest to 'x' is duplicated in several places. Add a new include - util_macros.h - and two macros that implement this algorithm for arrays sorted both in ascending and descending order. Uses linear search. Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Sebastian Ott authored
bucket_find_contain() will search the bucket list for a dma_debug_entry. When the entry isn't found it needs to search other buckets too, since only the start address of a dma range is hashed (which might be in a different bucket). A copy of the dma_debug_entry is used to get the previous hash bucket but when its list is searched the original dma_debug_entry is to be used not its modified copy. This fixes false "device driver tries to sync DMA memory it has not allocated" warnings. Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Horia Geanta <horia.geanta@freescale.com> Cc: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Rasmus Villemoes authored
The most expensive part of decimal conversion is the divisions by 10 (albeit done using reciprocal multiplication with appropriately chosen constants). I decided to see if one could eliminate around half of these multiplications by emitting two digits at a time, at the cost of a 200 byte lookup table, and it does indeed seem like there is something to be gained, especially on 64 bits. Microbenchmarking shows improvements ranging from -50% (for numbers uniformly distributed in [0, 2^64-1]) to -25% (for numbers heavily biased toward the smaller end, a more realistic distribution). On a larger scale, perf shows that top, one of the big consumers of /proc data, uses 0.5-1.0% fewer cpu cycles. I had to jump through some hoops to get the 32 bit code to compile and run on my 64 bit machine, so I'm not sure how relevant these numbers are, but just for comparison the microbenchmark showed improvements between -30% and -10%. The bloat-o-meter costs are around 150 bytes (the generated code is a little smaller, so it's not the full 200 bytes) on both 32 and 64 bit. I'm aware that extra cache misses won't show up in a microbenchmark as used above, but on the other hand decimal conversions often happen in bulk (for example in the case of top). I have of course tested that the new code generates the same output as the old, for both the first and last 1e10 numbers in [0,2^64-1] and 4e9 'random' numbers in-between. Test and verification code on github: https://github.com/Villemoes/dec. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Tested-by: Jeff Epler <jepler@unpythonic.net> Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Yury Norov authored
This file contains implementation for all find_*_bit{,_le} So giving it more generic name looks reasonable. Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: George Spelvin <linux@horizon.com> Cc: Alexey Klimov <klimov.linux@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mark Salter <msalter@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Thomas Graf <tgraf@suug.ch> Cc: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Yury Norov authored
Currently all 'find_*_bit' family is located in lib/find_next_bit.c, except 'find_last_bit', which is in lib/find_last_bit.c. It seems, there's no major benefit to have it separated. Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: George Spelvin <linux@horizon.com> Cc: Alexey Klimov <klimov.linux@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mark Salter <msalter@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Thomas Graf <tgraf@suug.ch> Cc: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-
Yury Norov authored
This patchset does rework to find_bit function family to achieve better performance, and decrease size of text. All rework is done in patch 1. Patches 2 and 3 are about code moving and renaming. It was boot-tested on x86_64 and MIPS (big-endian) machines. Performance tests were ran on userspace with code like this: /* addr[] is filled from /dev/urandom */ start = clock(); while (ret < nbits) ret = find_next_bit(addr, nbits, ret + 1); end = clock(); printf("%ld\t", (unsigned long) end - start); On Intel(R) Core(TM) i7-3770 CPU @ 3.40GHz measurements are: (for find_next_bit, nbits is 8M, for find_first_bit - 80K) find_next_bit: find_first_bit: new current new current 26932 43151 14777 14925 26947 43182 14521 15423 26507 43824 15053 14705 27329 43759 14473 14777 26895 43367 14847 15023 26990 43693 15103 15163 26775 43299 15067 15232 27282 42752 14544 15121 27504 43088 14644 14858 26761 43856 14699 15193 26692 43075 14781 14681 27137 42969 14451 15061 ... ... find_next_bit performance gain is 35-40%; find_first_bit - no measurable difference. On ARM machine, there is arch-specific implementation for find_bit. Thanks a lot to George Spelvin and Rasmus Villemoes for hints and helpful discussions. This patch (of 3): New implementations takes less space in source file (see diffstat) and in object. For me it's 710 vs 453 bytes of text. It also shows better performance. find_last_bit description fixed due to obvious typo. [akpm@linux-foundation.org: include linux/bitmap.h, per Rasmus] Signed-off-by: Yury Norov <yury.norov@gmail.com> Reviewed-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Reviewed-by: George Spelvin <linux@horizon.com> Cc: Alexey Klimov <klimov.linux@gmail.com> Cc: David S. Miller <davem@davemloft.net> Cc: Daniel Borkmann <dborkman@redhat.com> Cc: Hannes Frederic Sowa <hannes@stressinduktion.org> Cc: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Mark Salter <msalter@redhat.com> Cc: AKASHI Takahiro <takahiro.akashi@linaro.org> Cc: Thomas Graf <tgraf@suug.ch> Cc: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-