25 Jul, 2019
1 commit
-
The IPI code of x86 needs to evaluate whether the target cpumask is equal
to the cpu_online_mask or equal except for the calling CPU.To replace the current implementation which requires the usage of a
temporary cpumask, which might involve allocations, add a new function
which compares a cpumask to the result of two other cpumasks which are
or'ed together before comparison.This allows to make the required decision in one go and the calling code
then can check for the calling CPU being set in the target mask with
cpumask_test_cpu().Signed-off-by: Thomas Gleixner
Acked-by: Peter Zijlstra (Intel)
Link: https://lkml.kernel.org/r/20190722105220.585449120@linutronix.de
19 Jun, 2019
1 commit
-
Based on 2 normalized pattern(s):
this source code is licensed under the gnu general public license
version 2 see the file copying for more detailsthis source code is licensed under general public license version 2
seeextracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 52 file(s).
Signed-off-by: Thomas Gleixner
Reviewed-by: Enrico Weigelt
Reviewed-by: Allison Randal
Reviewed-by: Alexios Zavras
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.449021192@linutronix.de
Signed-off-by: Greg Kroah-Hartman
15 May, 2019
4 commits
-
Remove __bitmap_parselist helper and split the function to logical
parts.[ynorov@marvell.com: v5]
Link: http://lkml.kernel.org/r/20190416063801.20134-3-ynorov@marvell.com
Link: http://lkml.kernel.org/r/20190405173211.11373-3-ynorov@marvell.com
Signed-off-by: Yury Norov
Reviewed-by: Andy Shevchenko
Cc: Arnd Bergmann
Cc: Kees Cook
Cc: Matthew Wilcox
Cc: Mike Travis
Cc: Rasmus Villemoes
Cc: Tetsuo Handa
Cc: Guenter Roeck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "lib: rework bitmap_parselist and tests", v5.
bitmap_parselist has been evolved from a pretty simple idea for long and
now lacks for refactoring. It is not structured, has nested loops and a
set of opaque-named variables.Things are more complicated because bitmap_parselist() is a part of user
interface, and its behavior should not change.In this patchset
- bitmap_parselist_user() made a wrapper on bitmap_parselist();
- bitmap_parselist() reworked (patch 2);
- time measurement in test_bitmap_parselist switched to ktime_get
(patch 3);
- new tests introduced (patch 4), and
- bitmap_parselist_user() testing enabled with the same testset as
bitmap_parselist() (patch 5).This patch (of 5):
Currently we parse user data byte after byte which leads to
overcomplification of parsing algorithm. The only user of
bitmap_parselist_user() is not performance-critical, and so we can
duplicate user data to kernel buffer and simply call bitmap_parselist().
This rework lets us unify and simplify bitmap_parselist() and
bitmap_parselist_user(), which is done in the following patch.Link: http://lkml.kernel.org/r/20190405173211.11373-2-ynorov@marvell.com
Signed-off-by: Yury Norov
Reviewed-by: Andy Shevchenko
Cc: Rasmus Villemoes
Cc: Arnd Bergmann
Cc: Kees Cook
Cc: Matthew Wilcox
Cc: Tetsuo Handa
Cc: Mike Travis
Cc: Guenter Roeck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The bitmap_remap, _bitremap, _onto and _fold functions are only used,
via their node_ wrappers, in mm/mempolicy.c, which is only built for
CONFIG_NUMA. The helper bitmap_ord_to_pos used by these functions is
global, but its only external caller is node_random() in lib/nodemask.c,
which is also guarded by CONFIG_NUMA.For !CONFIG_NUMA:
add/remove: 0/6 grow/shrink: 0/0 up/down: 0/-621 (-621)
Function old new delta
bitmap_pos_to_ord 20 - -20
bitmap_ord_to_pos 70 - -70
bitmap_bitremap 81 - -81
bitmap_fold 113 - -113
bitmap_onto 123 - -123
bitmap_remap 214 - -214
Total: Before=4776, After=4155, chg -13.00%Link: http://lkml.kernel.org/r/20190329205353.6010-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes
Cc: Andy Shevchenko
Cc: Yury Norov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
AFAICT, there have never been any callers of these functions outside
mm/mempolicy.c (via their nodemask.h wrappers). In particular, no
modular code has ever used them, and given their somewhat exotic
semantics, I highly doubt they will ever find such a use. In any case,
no need to export them currently.Link: http://lkml.kernel.org/r/20190329205353.6010-1-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes
Cc: Andy Shevchenko
Cc: Yury Norov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
04 Jan, 2019
1 commit
-
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access. But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model. And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.There were a couple of notable cases:
- csky still had the old "verify_area()" name as an alias.
- the iter_iov code had magical hardcoded knowledge of the actual
values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
really used it)- microblaze used the type argument for a debug printout
but other than those oddities this should be a total no-op patch.
I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something. Any missed conversion should be trivially fixable, though.Signed-off-by: Linus Torvalds
31 Oct, 2018
3 commits
-
len is guaranteed to lie in [1, PAGE_SIZE]. If scnprintf is called with a
buffer size of 1, it is guaranteed to return 0. So in the extremely
unlikely case of having just one byte remaining in the page, let's just
call scnprintf anyway. The only difference is that this will write a '\0'
to that final byte in the page, but that's an improvement: We now
guarantee that after the call, buf is a properly terminated C string of
length exactly the return value.Link: http://lkml.kernel.org/r/20180818131623.8755-8-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes
Reviewed-by: Andy Shevchenko
Cc: Yury Norov
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
For various alignments of buf, the current expression computes
4096 ok
4095 ok
8190
8189
...
4097i.e., if the caller has already written two bytes into the page buffer,
len is 8190 rather than 4094, because PTR_ALIGN aligns up to the next
boundary. So if the printed version of the bitmap is huge, scnprintf()
ends up writing beyond the page boundary.I don't think any current callers actually write anything before
bitmap_print_to_pagebuf, but the API seems to be designed to allow it.[akpm@linux-foundation.org: use offset_in_page(), per Andy]
[akpm@linux-foundation.org: include mm.h for offset_in_page()]
Link: http://lkml.kernel.org/r/20180818131623.8755-7-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes
Reviewed-by: Andy Shevchenko
Cc: Yury Norov
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This promise is violated in a number of places, e.g. already in the
second function below this paragraph. Since I don't think anybody relies
on this being true, and since actually honouring it would hurt performance
and code size in various places, just remove the paragraph.Link: http://lkml.kernel.org/r/20180818131623.8755-2-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes
Reviewed-by: Andy Shevchenko
Cc: Yury Norov
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
23 Aug, 2018
1 commit
-
nbits == 0 is safe to be supplied to the function body, so remove
unnecessary checks in bitmap_to_arr32() and bitmap_from_arr32().Link: http://lkml.kernel.org/r/20180531131914.44352-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko
Acked-by: Yury Norov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Aug, 2018
1 commit
-
Pull input updates from Dmitry Torokhov:
- a new driver for Rohm BU21029 touch controller
- new bitmap APIs: bitmap_alloc, bitmap_zalloc and bitmap_free
- updates to Atmel, eeti. pxrc and iforce drivers
- assorted driver cleanups and fixes.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: (57 commits)
MAINTAINERS: Add PhoenixRC Flight Controller Adapter
Input: do not use WARN() in input_alloc_absinfo()
Input: mark expected switch fall-throughs
Input: raydium_i2c_ts - use true and false for boolean values
Input: evdev - switch to bitmap API
Input: gpio-keys - switch to bitmap_zalloc()
Input: elan_i2c_smbus - cast sizeof to int for comparison
bitmap: Add bitmap_alloc(), bitmap_zalloc() and bitmap_free()
md: Avoid namespace collision with bitmap API
dm: Avoid namespace collision with bitmap API
Input: pm8941-pwrkey - add resin entry
Input: pm8941-pwrkey - abstract register offsets and event code
Input: iforce - reorganize joystick configuration lists
Input: atmel_mxt_ts - move completion to after config crc is updated
Input: atmel_mxt_ts - don't report zero pressure from T9
Input: atmel_mxt_ts - zero terminate config firmware file
Input: atmel_mxt_ts - refactor config update code to add context struct
Input: atmel_mxt_ts - config CRC may start at T71
Input: atmel_mxt_ts - remove unnecessary debug on ENOMEM
Input: atmel_mxt_ts - remove duplicate setup of ABS_MT_PRESSURE
...
02 Aug, 2018
1 commit
-
A lot of code become ugly because of open coding allocations for bitmaps.
Introduce three helpers to allow users be more clear of intention
and keep their code neat.Note, due to multiple circular dependencies we may not provide
the helpers as inliners. For now we keep them exported and, perhaps,
at some point in the future we will sort out header inclusion and
inheritance.Signed-off-by: Andy Shevchenko
Signed-off-by: Dmitry Torokhov
08 Jun, 2018
1 commit
-
Use BITS_TO_LONGS() macro to avoid calculation of reminder (bits %
BITS_PER_LONG) On ARM64 it saves 5 instruction for function - 16 before
and 11 after.Link: http://lkml.kernel.org/r/20180411145914.6011-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov
Reviewed-by: Andrew Morton
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Apr, 2018
1 commit
-
syzbot is catching stalls at __bitmap_parselist()
(https://syzkaller.appspot.com/bug?id=ad7e0351fbc90535558514a71cd3edc11681997a).
The trigger isunsigned long v = 0;
bitmap_parselist("7:,", &v, BITS_PER_LONG);which results in hitting infinite loop at
while (a
Reported-by: Tetsuo Handa
Reported-by: syzbot
Cc: Noam Camus
Cc: Rasmus Villemoes
Cc: Matthew Wilcox
Cc: Mauro Carvalho Chehab
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Feb, 2018
2 commits
-
with bitmap_{from,to}_arr32 over the kernel. Additionally to it:
* __check_eq_bitmap() now takes single nbits argument.
* __check_eq_u32_array is not used in new test but may be used in
future. So I don't remove it here, but annotate as __used.Tested on arm64 and 32-bit BE mips.
[arnd@arndb.de: perf: arm_dsu_pmu: convert to bitmap_from_arr32]
Link: http://lkml.kernel.org/r/20180201172508.5739-2-ynorov@caviumnetworks.com
[ynorov@caviumnetworks.com: fix net/core/ethtool.c]
Link: http://lkml.kernel.org/r/20180205071747.4ekxtsbgxkj5b2fz@yury-thinkpad
Link: http://lkml.kernel.org/r/20171228150019.27953-2-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov
Signed-off-by: Arnd Bergmann
Cc: Ben Hutchings
Cc: David Decotigny ,
Cc: David S. Miller ,
Cc: Geert Uytterhoeven
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Cc: Heiner Kallweit
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patchset replaces bitmap_{to,from}_u32array with more simple and
standard looking copy-like functions.bitmap_from_u32array() takes 4 arguments (bitmap_to_u32array is similar):
- unsigned long *bitmap, which is destination;
- unsigned int nbits, the length of destination bitmap, in bits;
- const u32 *buf, the source; and
- unsigned int nwords, the length of source buffer in ints.In description to the function it is detailed like:
* copy min(nbits, 32*nwords) bits from @buf to @bitmap, remaining
* bits between nword and nbits in @bitmap (if any) are cleared.Having two size arguments looks unneeded and potentially dangerous.
It is unneeded because normally user of copy-like function should take
care of the size of destination and make it big enough to fit source
data.And it is dangerous because function may hide possible error if user
doesn't provide big enough bitmap, and data becomes silently dropped.That's why all copy-like functions have 1 argument for size of copying
data, and I don't see any reason to make bitmap_from_u32array()
different.One exception that comes in mind is strncpy() which also provides size
of destination in arguments, but it's strongly argued by the possibility
of taking broken strings in source. This is not the case of
bitmap_{from,to}_u32array().There is no many real users of bitmap_{from,to}_u32array(), and they all
very clearly provide size of destination matched with the size of
source, so additional functionality is not used in fact. Like this:
bitmap_from_u32array(to->link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS,
link_usettings.link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NU32);
Where:
#define __ETHTOOL_LINK_MODE_MASK_NU32 \
DIV_ROUND_UP(__ETHTOOL_LINK_MODE_MASK_NBITS, 32)In this patch, bitmap_copy_safe and bitmap_{from,to}_arr32 are introduced.
'Safe' in bitmap_copy_safe() stands for clearing unused bits in bitmap
beyond last bit till the end of last word. It is useful for hardening
API when bitmap is assumed to be exposed to userspace.bitmap_{from,to}_arr32 functions are replacements for
bitmap_{from,to}_u32array. They don't take unneeded nwords argument, and
so simpler in implementation and understanding.This patch suggests optimization for 32-bit systems - aliasing
bitmap_{from,to}_arr32 to bitmap_copy_safe.Other possible optimization is aliasing 64-bit LE bitmap_{from,to}_arr32 to
more generic function(s). But I didn't end up with the function that would
be helpful by itself, and can be used to alias 64-bit LE
bitmap_{from,to}_arr32, like bitmap_copy_safe() does. So I preferred to
leave things as is.The following patch switches kernel to new API and introduces test for it.
Discussion is here: https://lkml.org/lkml/2017/11/15/592
[ynorov@caviumnetworks.com: rename bitmap_copy_safe to bitmap_copy_clear_tail]
Link: http://lkml.kernel.org/r/20180201172508.5739-3-ynorov@caviumnetworks.com
Link: http://lkml.kernel.org/r/20171228150019.27953-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov
Cc: Ben Hutchings
Cc: David Decotigny ,
Cc: David S. Miller ,
Cc: Geert Uytterhoeven
Cc: Matthew Wilcox
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
20 Oct, 2017
1 commit
-
There are some good comments about bitmap operations in lib/bitmap.c
and include/linux/bitmap.h, so format them for document generation and
pull them into core-api/kernel-api.rst.I converted the "tables" of functions from using tabs to using spaces
so that they are more readable in the source file and in the generated
output.Signed-off-by: Randy Dunlap
Signed-off-by: Jonathan Corbet
09 Sep, 2017
1 commit
-
Current implementation of bitmap_parselist() uses a static variable to
save local state while setting bits in the bitmap. It is obviously wrong
if we assume execution in multiprocessor environment. Fortunately, it's
possible to rewrite this portion of code to avoid using the static
variable.It is also possible to set bits in the mask per-range with bitmap_set(),
not per-bit, as it is implemented now, with set_bit(); which is way
faster.The important side effect of this change is that setting bits in this
function from now is not per-bit atomic and less memory-ordered. This is
because set_bit() guarantees the order of memory accesses, while
bitmap_set() does not. I think that it is the advantage of the new
approach, because the bitmap_parselist() is intended to initialise bit
arrays, and user should protect the whole bitmap during initialisation if
needed. So protecting individual bits looks expensive and useless. Also,
other range-oriented functions in lib/bitmap.c don't worry much about
atomicity.With all that, setting 2k bits in map with the pattern like 0-2047:128/256
becomes ~50 times faster after applying the patch in my testing
environment (arm64 hosted on qemu).The second patch of the series adds the test for bitmap_parselist(). It's
not intended to cover all tricky cases, just to make sure that I didn't
screw up during rework.Link: http://lkml.kernel.org/r/20170807225438.16161-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov
Cc: Noam Camus
Cc: Rasmus Villemoes
Cc: Matthew Wilcox
Cc: Mauro Carvalho Chehab
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jul, 2017
1 commit
-
We have eight users calling bitmap_clear for a single bit and seventeen
calling bitmap_set for a single bit. Rather than fix all of them to
call __clear_bit or __set_bit, turn bitmap_clear and bitmap_set into
inline functions and make this special case efficient.Link: http://lkml.kernel.org/r/20170628153221.11322-3-willy@infradead.org
Signed-off-by: Matthew Wilcox
Acked-by: Rasmus Villemoes
Cc: Martin Schwidefsky
Cc: Matthew Wilcox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Apr, 2017
1 commit
-
Fix the following issues:
./lib/bitmap.c:869: WARNING: Definition list ends without a blank line; unexpected unindent.
./lib/bitmap.c:876: WARNING: Inline emphasis start-string without end-string.
./lib/bitmap.c:508: ERROR: Unexpected indentation.And make sure that a table and a footnote will use the right tags.
Signed-off-by: Mauro Carvalho Chehab
Signed-off-by: Jonathan Corbet
12 Oct, 2016
1 commit
-
Today there are platforms with many CPUs (up to 4K). Trying to boot only
part of the CPUs may result in too long string.For example lets take NPS platform that is part of arch/arc. This
platform have SMP system with 256 cores each with 16 HW threads (SMT
machine) where HW thread appears as CPU to the kernel. In this example
there is total of 4K CPUs. When one tries to boot only part of the HW
threads from each core the string representing the map may be long... For
example if for sake of performance we decided to boot only first half of
HW threads of each core the map will look like:
0-7,16-23,32-39,...,4080-4087This patch introduce new syntax to accommodate with such use case. I
added an optional postfix to a range of CPUs which will choose according
to given modulo the desired range of reminders i.e.::sed_size/group_size
For example, above map can be described in new syntax like this:
0-4095:8/16Note that this patch is backward compatible with current syntax.
[akpm@linux-foundation.org: rework documentation]
Link: http://lkml.kernel.org/r/1473579629-4283-1-git-send-email-noamca@mellanox.com
Signed-off-by: Noam Camus
Cc: David Decotigny
Cc: Ben Hutchings
Cc: David S. Miller
Cc: Pan Xinhui
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jul, 2016
1 commit
-
struct thread_info is a legacy mess. To prepare for its partial removal,
move thread_info::addr_limit out.As an added benefit, this way is simpler.
Signed-off-by: Andy Lutomirski
Cc: Borislav Petkov
Cc: Brian Gerst
Cc: Denys Vlasenko
Cc: H. Peter Anvin
Cc: Josh Poimboeuf
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Link: http://lkml.kernel.org/r/15bee834d09402b47ac86f2feccdf6529f9bc5b0.1468527351.git.luto@kernel.org
Signed-off-by: Ingo Molnar
20 Feb, 2016
1 commit
-
Aimed at transferring bitmaps to/from user-space in a 32/64-bit agnostic
way.Tested:
unit tests (next patch) on qemu i386, x86_64, ppc, ppc64 BE and LE,
ARM.Signed-off-by: David Decotigny
Reviewed-by: Ben Hutchings
Signed-off-by: David S. Miller
11 Sep, 2015
3 commits
-
In __bitmap_parselist we can accept whitespaces on head or tail during
every parsing procedure. If input has valid ranges, there is no reason to
reject the user.For example, bitmap_parselist(" 1-3, 5, ", &mask, nmaskbits). After
separating the string, we get " 1-3", " 5", and " ". It's possible and
reasonable to accept such string as long as the parsing result is correct.Signed-off-by: Pan Xinhui
Cc: Yury Norov
Cc: Chris Metcalf
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If string end with '-', for exapmle, bitmap_parselist("1,0-",&mask,
nmaskbits), It is not in a valid pattern, so add a check after loop.
Return -EINVAL on such condition.Signed-off-by: Pan Xinhui
Cc: Yury Norov
Cc: Chris Metcalf
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We can avoid in-loop incrementation of ndigits. Save current totaldigits
to ndigits before loop, and check ndigits against totaldigits after the
loop.Signed-off-by: Pan Xinhui
Cc: Yury Norov
Cc: Chris Metcalf
Cc: Rasmus Villemoes
Cc: Sudeep Holla
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
26 Jun, 2015
2 commits
-
bitmap_print_to_pagebuf uses scnprintf to copy the cpumask/list to page
buffer. It handles the newline and trailing null character explicitly.It's unnecessary and also partially duplicated as scnprintf already adds
trailing null character. The newline can be passed through format
string to scnprintf. This patch does that simplification.However theoretically there's one behavior difference: when the buffer
is too small, the original code would still output '\n' at the end while
the new code(with this patch) would just continue to print the formatted
string. Since this function is dealing with only page buffers, it's
highly unlikely to hit that corner case.This patch will help in auditing the users of bitmap_print_to_pagebuf to
verify that the buffer passed is large enough and get rid of it
completely by replacing them with direct scnprintf()[akpm@linux-foundation.org: tweak comment]
Signed-off-by: Sudeep Holla
Suggested-by: Pawel Moll
Cc: Tejun Heo
Cc: "Peter Zijlstra (Intel)"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
bitmap_parselist("", &mask, nmaskbits) will erroneously set bit zero in
the mask. The same bug is visible in cpumask_parselist() since it is
layered on top of the bitmask code, e.g. if you boot with "isolcpus=",
you will actually end up with cpu zero isolated.The bug was introduced in commit 4b060420a596 ("bitmap, irq: add
smp_affinity_list interface to /proc/irq") when bitmap_parselist() was
generalized to support userspace as well as kernelspace.Fixes: 4b060420a596 ("bitmap, irq: add smp_affinity_list interface to /proc/irq")
Signed-off-by: Chris Metcalf
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Apr, 2015
1 commit
-
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
Cc: George Spelvin
Cc: Alexey Klimov
Cc: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Feb, 2015
10 commits
-
Now that all bitmap formatting usages have been converted to
'%*pb[l]', the separate formatting functions are unnecessary. The
following functions are removed.* bitmap_scn[list]printf()
* cpumask_scnprintf(), cpulist_scnprintf()
* [__]nodemask_scnprintf(), [__]nodelist_scnprintf()
* seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]()
* seq_buf_bitmask()Signed-off-by: Tejun Heo
Cc: Rusty Russell
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
printk and friends can now format bitmaps using '%*pb[l]'. cpumask
and nodemask also provide cpumask_pr_args() and nodemask_pr_args()
respectively which can be used to generate the two printf arguments
necessary to format the specified cpu/nodemask.Signed-off-by: Tejun Heo
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
bitmap and its derivatives such as cpumask and nodemask currently only
provide formatting functions which put the output string into the
provided buffer; however, how long this buffer should be isn't defined
anywhere and given that some of these bitmaps can be too large to be
formatted into an on-stack buffer it users sometimes are unnecessarily
forced to come up with creative solutions and compromises for the
buffer just to printk these bitmaps.There have been a couple different attempts at making this easier.
1. Way back, PeterZ tried printk '%pb' extension with the precision
for bit width - '%.*pb'. This was intuitive and made sense but
unfortunately triggered a compile warning about using precision
for a pointer.http://lkml.kernel.org/g/1336577562.2527.58.camel@twins
2. I implemented bitmap_pr_cont[_list]() and its wrappers for cpumask
and nodemask. This works but PeterZ pointed out that pr_cont's
tendency to produce broken lines when multiple CPUs are printing is
bothering considering the usages.http://lkml.kernel.org/g/1418226774-30215-3-git-send-email-tj@kernel.org
So, this patch is another attempt at teaching printk and friends how
to print bitmaps. It's almost identical to what PeterZ tried with
precision but it uses the field width for the number of bits instead
of precision. The format used is '%*pb[l]', with the optional
trailing 'l' specifying list format instead of hex masks.This is a valid format string and doesn't trigger compiler warnings;
however, it does make it impossible to specify output field width when
printing bitmaps. I think this is an acceptable trade-off given how
much easier it makes printing bitmaps and that we don't have any
in-kernel user which is using the field width specification. If any
future user wants to use field width with a bitmap, it'd have to
format the bitmap into a string buffer and then print that buffer with
width spec, which isn't different from how it should be done now.This patch implements bitmap[_list]_string() which are called from the
vsprintf pointer() formatting function. The implementation is mostly
identical to bitmap_scn[list]printf() except that the output is
performed in the vsprintf way. These functions handle formatting into
too small buffers and sprintf() family of functions report the correct
overrun output length.bitmap_scn[list]printf() are now thin wrappers around scnprintf().
Signed-off-by: Tejun Heo
Acked-by: Peter Zijlstra (Intel)
Cc: "David S. Miller"
Cc: "James E.J. Bottomley"
Cc: "John W. Linville"
Cc: "Paul E. McKenney"
Cc: Benjamin Herrenschmidt
Cc: Chris Metcalf
Cc: Chris Zankel
Cc: Christoph Lameter
Cc: Dmitry Torokhov
Cc: Fenghua Yu
Cc: Greg Kroah-Hartman
Cc: Ingo Molnar
Cc: Li Zefan
Cc: Max Filippov
Cc: Mike Travis
Cc: Pekka Enberg
Cc: Russell King
Cc: Rusty Russell
Cc: Steffen Klassert
Cc: Steven Rostedt
Cc: Thomas Gleixner
Cc: Tony Luck
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The first of these conditionals is completely redundant: If k == lim-1, we
must have off==0, so the second conditional will also trigger and then it
wouldn't matter if upper had some high bits set. But the second
conditional is in fact also redundant, since it only serves to clear out
some high-order "don't care" bits of dst, about which no guarantee is
made.Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We can shift the bits from lower and upper into place before assembling
dst[k + off]; moving the shift of lower into the branch where we already
know that rem is non-zero allows us to remove a conditional.Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
gcc can generate slightly better code for stuff like "nbits %
BITS_PER_LONG" when it knows nbits is not negative. Since negative size
bitmaps or shift amounts don't make sense, change these parameters of
bitmap_shift_right to unsigned.If off >= lim (which requires shift >= nbits), k is initialized with a
large positive value, but since I've let k continue to be signed, the loop
will never run and dst will be zeroed as expected. Inside the loop, k is
guaranteed to be non-negative, so the fact that it is promoted to unsigned
in the various expressions it appears in is harmless.Also use "shift" and "nbits" consistently for the parameter names.
Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If left is 0, we can just let mask be ~0UL, so that anding with it is a
no-op. Conveniently, BITMAP_LAST_WORD_MASK provides precisely what we
need, and we can eliminate left.Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the condition k==lim-1 is true, we must have off == 0 (otherwise, k
could never become that big). But in that case we have upper == 0 and
hence dst[k] == (src[k] & mask) >> rem. Since mask consists of a
consecutive range of bits starting from the LSB, anding dst[k] with mask
is a no-op.Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We can shift the bits from lower and upper into place before assembling
dst[k]; moving the shift of upper into the branch where we already know
that rem is non-zero allows us to remove a conditional.Signed-off-by: Rasmus Villemoes
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I've previously changed the nbits parameter of most bitmap_* functions to
unsigned; now it is bitmap_shift_{left,right}'s turn. This alone saves
some .text, but while at it I found that there were a few other things one
could do. The end result of these seven patches is$ scripts/bloat-o-meter /tmp/bitmap.o.{old,new}
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-328 (-328)
function old new delta
__bitmap_shift_right 384 226 -158
__bitmap_shift_left 306 136 -170and less importantly also a smaller stack footprint
$ stack-o-meter.pl master bitmap
file function old new delta
lib/bitmap.o __bitmap_shift_right 24 8 -16
lib/bitmap.o __bitmap_shift_left 24 0 -24For each pair of 0
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
