- 07 May, 2021 30 commits
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Richard Fitzgerald authored
crc8() does not change the data passed to it, so the pointer argument should be declared const. This avoids callers that receive const data having to cast it to a non-const pointer to call crc8(). Link: https://lkml.kernel.org/r/20210329122409.3291-1-rf@opensource.cirrus.comSigned-off-by:
Richard Fitzgerald <rf@opensource.cirrus.com> Acked-by:
Randy Dunlap <rdunlap@infradead.org> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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Bhaskar Chowdhury authored
s/macthing/matching/ Link: https://lkml.kernel.org/r/20210326131530.30481-1-unixbhaskar@gmail.comSigned-off-by:
Bhaskar Chowdhury <unixbhaskar@gmail.com> Signed-off-by:
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ToastC authored
Replace beautiully with beautifully Link: https://lkml.kernel.org/r/20210315090633.9759-1-mrtoastcheng@gmail.comSigned-off-by:
ShihCheng Tu <mrtoastcheng@gmail.com> Signed-off-by:
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Wang Qing authored
Smatch gives the warning: lib/decompress_unlzma.c:395 process_bit1() warn: inconsistent indenting Link: https://lkml.kernel.org/r/1614567775-4478-1-git-send-email-wangqing@vivo.comSigned-off-by:
Wang Qing <wangqing@vivo.com> Signed-off-by:
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Bhaskar Chowdhury authored
s/buid/build/ Link: https://lkml.kernel.org/r/20210301123129.18754-1-unixbhaskar@gmail.comSigned-off-by:
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Yury Norov authored
Add myself as maintainer for bitmap API and Andy and Rasmus as reviewers. Link: https://lkml.kernel.org/r/20210401003153.97325-13-yury.norov@gmail.comSigned-off-by:
Yury Norov <yury.norov@gmail.com> Acked-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Acked-by:
Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Alexey Klimov <aklimov@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Sterba <dsterba@suse.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jianpeng Ma <jianpeng.ma@intel.com> Cc: Joe Perches <joe@perches.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Rich Felker <dalias@libc.org> Cc: Stefano Brivio <sbrivio@redhat.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Wolfram Sang <wsa+renesas@sang-engineering.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by:
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Yury Norov authored
Add fast paths to find_*_bit() functions as per kernel implementation. Link: https://lkml.kernel.org/r/20210401003153.97325-12-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
Similarly to bitmap functions, users would benefit if we'll handle a case of small-size bitmaps that fit into a single word. While here, move the find_last_bit() declaration to bitops/find.h where other find_*_bit() functions sit. Link: https://lkml.kernel.org/r/20210401003153.97325-11-yury.norov@gmail.comSigned-off-by:
Andy Shevchenko <andy.shevchenko@gmail.com> Cc: Alexey Klimov <aklimov@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Sterba <dsterba@suse.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Jianpeng Ma <jianpeng.ma@intel.com> Cc: Joe Perches <joe@perches.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Rich Felker <dalias@libc.org> Cc: Stefano Brivio <sbrivio@redhat.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Wolfram Sang <wsa+renesas@sang-engineering.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by:
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Yury Norov authored
Similarly to bitmap functions, find_next_*_bit() users will benefit if we'll handle a case of bitmaps that fit into a single word inline. In the very best case, the compiler may replace a function call with a few instructions. This is the quite typical find_next_bit() user: unsigned int cpumask_next(int n, const struct cpumask *srcp) { /* -1 is a legal arg here. */ if (n != -1) cpumask_check(n); return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1); } EXPORT_SYMBOL(cpumask_next); Currently, on ARM64 the generated code looks like this: 0000000000000000 <cpumask_next>: 0: a9bf7bfd stp x29, x30, [sp, #-16]! 4: 11000402 add w2, w0, #0x1 8: aa0103e0 mov x0, x1 c: d2800401 mov x1, #0x40 // #64 10: 910003fd mov x29, sp 14: 93407c42 sxtw x2, w2 18: 94000000 bl 0 <find_next_bit> 1c: a8c17bfd ldp x29, x30, [sp], #16 20: d65f03c0 ret 24: d503201f nop After applying this patch: 0000000000000140 <cpumask_next>: 140: 11000400 add w0, w0, #0x1 144: 93407c00 sxtw x0, w0 148: f100fc1f cmp x0, #0x3f 14c: 54000168 b.hi 178 <cpumask_next+0x38> // b.pmore 150: f9400023 ldr x3, [x1] 154: 92800001 mov x1, #0xffffffffffffffff // #-1 158: 9ac02020 lsl x0, x1, x0 15c: 52800802 mov w2, #0x40 // #64 160: 8a030001 and x1, x0, x3 164: dac00020 rbit x0, x1 168: f100003f cmp x1, #0x0 16c: dac01000 clz x0, x0 170: 1a800040 csel w0, w2, w0, eq // eq = none 174: d65f03c0 ret 178: 52800800 mov w0, #0x40 // #64 17c: d65f03c0 ret find_next_bit() call is replaced with 6 instructions. find_next_bit() itself is 41 instructions plus function call overhead. Despite inlining, the scripts/bloat-o-meter report smaller .text size after applying the series: add/remove: 11/9 grow/shrink: 233/176 up/down: 5780/-6768 (-988) Link: https://lkml.kernel.org/r/20210401003153.97325-10-yury.norov@gmail.comSigned-off-by: -
Yury Norov authored
Sync the implementation with recent kernel changes. Link: https://lkml.kernel.org/r/20210401003153.97325-9-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
lib/find_bit.c declares five single-line wrappers for _find_next_bit(). We may turn those wrappers to inline functions. It eliminates unneeded function calls and opens room for compile-time optimizations. Link: https://lkml.kernel.org/r/20210401003153.97325-8-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
Sync implementation with the kernel and move the macro from tools/include/linux/bitmap.h to tools/include/asm-generic/bitsperlong.h Link: https://lkml.kernel.org/r/20210401003153.97325-7-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
find_bit would also benefit from small_const_nbits() optimizations. The detailed comment is provided by Rasmus Villemoes. Link: https://lkml.kernel.org/r/20210401003153.97325-6-yury.norov@gmail.comSuggested-by:
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Yury Norov authored
m68k and sh include bitmap/{find,le}.h prior to ffs/fls headers. New fast-path implementation in find.h requires ffs/fls. Reordering the headers inclusion sequence helps to prevent compile-time implicit function declaration error. [yury.norov@gmail.com: h8300: rearrange headers inclusion order in asm/bitops] Link: https://lkml.kernel.org/r/20210406183625.794227-1-yury.norov@gmail.com Link: https://lkml.kernel.org/r/20210401003153.97325-5-yury.norov@gmail.comSigned-off-by:Geert Uytterhoeven <geert@linux-m68k.org> Acked-by:
Guenter Roeck <linux@roeck-us.net> Cc: Alexey Klimov <aklimov@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: David Sterba <dsterba@suse.com> Cc: Dennis Zhou <dennis@kernel.org> Cc: Jianpeng Ma <jianpeng.ma@intel.com> Cc: Joe Perches <joe@perches.com> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Rich Felker <dalias@libc.org> Cc: Stefano Brivio <sbrivio@redhat.com> Cc: Wei Yang <richard.weiyang@linux.alibaba.com> Cc: Wolfram Sang <wsa+renesas@sang-engineering.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by:
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Yury Norov authored
Kernel version generates better code. Link: https://lkml.kernel.org/r/20210401003153.97325-4-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
Some functions in tools/include/linux/bitmap.h declare nbits as int. In the kernel nbits is declared as unsigned int. Link: https://lkml.kernel.org/r/20210401003153.97325-3-yury.norov@gmail.comSigned-off-by:
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Yury Norov authored
Patch series "lib/find_bit: fast path for small bitmaps", v6. Bitmap operations are much simpler and faster in case of small bitmaps which fit into a single word. In linux/bitmap.c we have a machinery that allows compiler to replace actual function call with a few instructions if bitmaps passed into the function are small and their size is known at compile time. find_*_bit() API lacks this functionality; but users will benefit from it a lot. One important example is cpumask subsystem when NR_CPUS <= BITS_PER_LONG. This patch (of 12): GENMASK(h, l) may be passed with unsigned types. In such case, type-limits warning is generated for example in case of GENMASK(h, 0). Link: https://lkml.kernel.org/r/20210401003153.97325-1-yury.norov@gmail.com Link: https://lkml.kernel.org/r/20210401003153.97325-2-yury.norov@gmail.comSigned-off-by:
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Rasmus Villemoes authored
init_groups is declared in both cred.h and init_task.h, but it is not actually referenced anywhere outside of cred.c where it is defined. So make it static and remove the declarations. Link: https://lkml.kernel.org/r/20210310220102.2484201-1-linux@rasmusvillemoes.dkSigned-off-by:
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Rasmus Villemoes authored
An async_func_t returns void - any errors encountered it has to stash somewhere for consumers to discover later. Link: https://lkml.kernel.org/r/20210226124355.2503524-1-linux@rasmusvillemoes.dkSigned-off-by:
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Wan Jiabing authored
Declaring struct pt_regs is unnecessary. On the one hand, there is no function using it; on the other hand, struct pt_regs has been declared in linux/kernel.h. Remove them. Link: https://lkml.kernel.org/r/20210401104834.1009157-1-wanjiabing@vivo.comSigned-off-by:
Wan Jiabing <wanjiabing@vivo.com> Signed-off-by:
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Andy Shevchenko authored
The bitmap.h header is used in a lot of code around the kernel. Besides that it includes kernel.h which sometimes makes a loop. The problem here is many unneeded loops that make header hell dependencies. For example, how may you move bitmap_zalloc() from C-file to the header? Currently it's impossible. And bitmap.h here is only the tip of an iceberg. kerne.h is a dump of everything that even has nothing in common at all. We may still have it, but in my new code I prefer to include only the headers that I want to use, without the bulk of unneeded kernel code. Break the loop by introducing align.h, including it in kernel.h and bitmap.h followed by replacing kernel.h with limits.h. Link: https://lkml.kernel.org/r/20210326170347.37441-1-andriy.shevchenko@linux.intel.comSigned-off-by:
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Matthew Wilcox (Oracle) authored
My UEK-derived config has 1030 files depending on pagemap.h before this change. Afterwards, just 326 files need to be rebuilt when I touch pagemap.h. I think blkdev.h is probably included too widely, but untangling that dependency is harder and this solves my problem. x86 allmodconfig builds, but there may be implicit include problems on other architectures. Link: https://lkml.kernel.org/r/20210309195747.283796-1-willy@infradead.orgSigned-off-by:
Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: Dan Williams <dan.j.williams@intel.com> [nvdimm] Acked-by: Jens Axboe <axboe@kernel.dk> [block] Reviewed-by:
Christoph Hellwig <hch@lst.de> Acked-by: Coly Li <colyli@suse.de> [bcache] Acked-by: Martin K. Petersen <martin.petersen@oracle.com> [scsi] Reviewed-by:
William Kucharski <william.kucharski@oracle.com> Signed-off-by:
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zhouchuangao authored
The function name should be modified to register_sysctl_paths instead of register_sysctl_table_path. Link: https://lkml.kernel.org/r/1615807194-79646-1-git-send-email-zhouchuangao@vivo.comSigned-off-by:
zhouchuangao <zhouchuangao@vivo.com> Signed-off-by:
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Alexey Dobriyan authored
Test that /proc instance mounted with mount -t proc -o subset=pid contains only ".", "..", "self", "thread-self" and pid directories. Note: Currently "subset=pid" doesn't return "." and ".." via readdir. This must be a bug. Link: https://lkml.kernel.org/r/YFYZZ7WGaZlsnChS@localhost.localdomainSigned-off-by:
Alexey Dobriyan <adobriyan@gmail.com> Acked-by:
Alexey Gladkov <gladkov.alexey@gmail.com> Signed-off-by:
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Alexey Dobriyan authored
Two checks in lookup and readdir code should be enough to not have third check in open code. Can't open what can't be looked up? Link: https://lkml.kernel.org/r/YFYYwIBIkytqnkxP@localhost.localdomainSigned-off-by:
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Alexey Dobriyan authored
Now that proc_ops are separate from file_operations and other operations it easy to check all instances to have ->proc_lseek hook and remove check in main code. Note: nonseekable_open() files naturally don't require ->proc_lseek. Garbage collect pde_lseek() function. [adobriyan@gmail.com: smoke test lseek()] Link: https://lkml.kernel.org/r/YG4OIhChOrVTPgdN@localhost.localdomain Link: https://lkml.kernel.org/r/YFYX0Bzwxlc7aBa/@localhost.localdomainSigned-off-by:
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Alexey Dobriyan authored
Can't look at this verbosity anymore. Link: https://lkml.kernel.org/r/YFYXAp/fgq405qcy@localhost.localdomainSigned-off-by:
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Colin Ian King authored
Currently the pde_is_permanent() check is being run on root multiple times rather than on the next proc directory entry. This looks like a copy-paste error. Fix this by replacing root with next. Addresses-Coverity: ("Copy-paste error") Link: https://lkml.kernel.org/r/20210318122633.14222-1-colin.king@canonical.com Fixes: d919b33d ("proc: faster open/read/close with "permanent" files") Signed-off-by:Colin Ian King <colin.king@canonical.com> Acked-by:
Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by:
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Randy Dunlap authored
Fix "no previous prototype" W=1 warnings from the kernel test robot: arch/alpha/lib/csum_partial_copy.c:349:1: error: no previous prototype for 'csum_and_copy_from_user' [-Werror=missing-prototypes] 349 | csum_and_copy_from_user(const void __user *src, void *dst, int len) | ^~~~~~~~~~~~~~~~~~~~~~~ arch/alpha/lib/csum_partial_copy.c:358:1: error: no previous prototype for 'csum_partial_copy_nocheck' [-Werror=missing-prototypes] 358 | csum_partial_copy_nocheck(const void *src, void *dst, int len) | ^~~~~~~~~~~~~~~~~~~~~~~~~ Link: https://lkml.kernel.org/r/20210425235749.19113-1-rdunlap@infradead.org Fixes: 808b49da ("alpha: turn csum_partial_copy_from_user() into csum_and_copy_from_user()") Signed-off-by:kernel test robot <lkp@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Signed-off-by:
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Randy Dunlap authored
'make ARCH=alpha W=1' reports a couple of old-style function definitions with missing parameter list, so fix those. arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_base': arch/alpha/kernel/pc873xx.c:16:21: warning: old-style function definition [-Wold-style-definition] 16 | unsigned int __init pc873xx_get_base() arch/alpha/kernel/pc873xx.c: In function 'pc873xx_get_model': arch/alpha/kernel/pc873xx.c:21:14: warning: old-style function definition [-Wold-style-definition] 21 | char *__init pc873xx_get_model() Link: https://lkml.kernel.org/r/20210421061312.30097-1-rdunlap@infradead.orgSigned-off-by:
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- 05 May, 2021 10 commits
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Marco Elver authored
Use the power-efficient work queue, to avoid the pathological case where we keep pinning ourselves on the same possibly idle CPU on systems that want to be power-efficient (https://lwn.net/Articles/731052/). Link: https://lkml.kernel.org/r/20210421105132.3965998-4-elver@google.comSigned-off-by:
Marco Elver <elver@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Hillf Danton <hdanton@sina.com> Cc: Jann Horn <jannh@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by:
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Marco Elver authored
The allocation wait timeout was initially added because of warnings due to CONFIG_DETECT_HUNG_TASK=y [1]. While the 1 sec timeout is sufficient to resolve the warnings (given the hung task timeout must be 1 sec or larger) it may cause unnecessary wake-ups if the system is idle: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Fix it by computing the timeout duration in terms of the current sysctl_hung_task_timeout_secs value. Link: https://lkml.kernel.org/r/20210421105132.3965998-3-elver@google.comSigned-off-by:
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Marco Elver authored
Patch series "kfence: optimize timer scheduling", v2. We have observed that mostly-idle systems with KFENCE enabled wake up otherwise idle CPUs, preventing such to enter a lower power state. Debugging revealed that KFENCE spends too much active time in toggle_allocation_gate(). While the first version of KFENCE was using all the right bits to be scheduling optimal, and thus power efficient, by simply using wait_event() + wake_up(), that code was unfortunately removed. As KFENCE was exposed to various different configs and tests, the scheduling optimal code slowly disappeared. First because of hung task warnings, and finally because of deadlocks when an allocation is made by timer code with debug objects enabled. Clearly, the "fixes" were not too friendly for devices that want to be power efficient. Therefore, let's try a little harder to fix the hung task and deadlock problems that we have with wait_event() + wake_up(), while remaining as scheduling friendly and power efficient as possible. Crucially, we need to defer the wake_up() to an irq_work, avoiding any potential for deadlock. The result with this series is that on the devices where we observed a power regression, power usage returns back to baseline levels. This patch (of 3): On mostly-idle systems, we have observed that toggle_allocation_gate() is a cause of frequent wake-ups, preventing an otherwise idle CPU to go into a lower power state. A late change in KFENCE's development, due to a potential deadlock [1], required changing the scheduling-friendly wait_event_timeout() and wake_up() to an open-coded wait-loop using schedule_timeout(). [1] https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com To avoid unnecessary wake-ups, switch to using wait_event_timeout(). Unfortunately, we still cannot use a version with direct wake_up() in __kfence_alloc() due to the same potential for deadlock as in [1]. Instead, add a level of indirection via an irq_work that is scheduled if we determine that the kfence_timer requires a wake_up(). Link: https://lkml.kernel.org/r/20210421105132.3965998-1-elver@google.com Link: https://lkml.kernel.org/r/20210421105132.3965998-2-elver@google.com Fixes: 0ce20dd8 ("mm: add Kernel Electric-Fence infrastructure") Signed-off-by:
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Marco Elver authored
After an out-of-bounds accesses, zero the guard page before re-protecting in kfence_guarded_free(). On one hand this helps make the failure mode of subsequent out-of-bounds accesses more deterministic, but could also prevent certain information leaks. Link: https://lkml.kernel.org/r/20210312121653.348518-1-elver@google.comSigned-off-by:
Alexander Potapenko <glider@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Jann Horn <jannh@google.com> Signed-off-by:
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Zhang Yunkai authored
'linux/compat.h' included in 'process_vm_access.c' is duplicated. Link: https://lkml.kernel.org/r/20210306132122.220431-1-zhang.yunkai@zte.com.cnSigned-off-by:
Zhang Yunkai <zhang.yunkai@zte.com.cn> Signed-off-by:
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Zhiyuan Dai authored
Various coding style tweaks to various files under mm/ [daizhiyuan@phytium.com.cn: mm/swapfile: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614223624-16055-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/sparse: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227288-19363-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmscan: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614227649-19853-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/compaction: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228218-20770-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/oom_kill: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228360-21168-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/shmem: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228504-21491-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/page_alloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228613-21754-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/filemap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1614228936-22337-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mlock: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613956588-2453-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/frontswap: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613962668-15045-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/vmalloc: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613963379-15988-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/memory_hotplug: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613971784-24878-1-git-send-email-daizhiyuan@phytium.com.cn [daizhiyuan@phytium.com.cn: mm/mempolicy: minor coding style tweaks] Link: https://lkml.kernel.org/r/1613972228-25501-1-git-send-email-daizhiyuan@phytium.com.cn Link: https://lkml.kernel.org/r/1614222374-13805-1-git-send-email-daizhiyuan@phytium.com.cnSigned-off-by:
Zhiyuan Dai <daizhiyuan@phytium.com.cn> Signed-off-by:
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songqiang authored
Delete/add some blank lines and some blank spaces Link: https://lkml.kernel.org/r/20210311095015.14277-1-songqiang@uniontech.comSigned-off-by:
songqiang <songqiang@uniontech.com> Reviewed-by:
David Hildenbrand <david@redhat.com> Signed-off-by:
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Ira Weiny authored
There are many places where kmap/memset/kunmap patterns occur. Use the newly lifted memzero_page() to eliminate direct uses of kmap and leverage the new core functions use of kmap_local_page(). The development of this patch was aided by the following coccinelle script: // <smpl> // SPDX-License-Identifier: GPL-2.0-only // Find kmap/memset/kunmap pattern and replace with memset*page calls // // NOTE: Offsets and other expressions may be more complex than what the script // will automatically generate. Therefore a catchall rule is provided to find // the pattern which then must be evaluated by hand. // // Confidence: Low // Copyright: (C) 2021 Intel Corporation // URL: http://coccinelle.lip6.fr/ // Comments: // Options: // // Then the memset pattern // @ memset_rule1 @ expression page, V, L, Off; identifier ptr; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( -memset(ptr, 0, L); +memzero_page(page, 0, L); | -memset(ptr + Off, 0, L); +memzero_page(page, Off, L); | -memset(ptr, V, L); +memset_page(page, V, 0, L); | -memset(ptr + Off, V, L); +memset_page(page, V, Off, L); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule1 @ identifier memset_rule1.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // // Catch all // @ memset_rule2 @ expression page; identifier ptr; expression GenTo, GenSize, GenValue; type VP; @@ ( -VP ptr = kmap(page); | -ptr = kmap(page); | -VP ptr = kmap_atomic(page); | -ptr = kmap_atomic(page); ) <+... ( // // Some call sites have complex expressions within the memset/memcpy // The follow are catch alls which need to be evaluated by hand. // -memset(GenTo, 0, GenSize); +memzero_pageExtra(page, GenTo, GenSize); | -memset(GenTo, GenValue, GenSize); +memset_pageExtra(page, GenValue, GenTo, GenSize); ) ...+> ( -kunmap(page); | -kunmap_atomic(ptr); ) // Remove any pointers left unused @ depends on memset_rule2 @ identifier memset_rule2.ptr; type VP, VP1; @@ -VP ptr; ... when != ptr; ? VP1 ptr; // </smpl> Link: https://lkml.kernel.org/r/20210309212137.2610186-4-ira.weiny@intel.comSigned-off-by:
Ira Weiny <ira.weiny@intel.com> Reviewed-by:
David Sterba <dsterba@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Cc: Chris Mason <clm@fb.com> Cc: Josef Bacik <josef@toxicpanda.com> Signed-off-by:
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Ira Weiny authored
Patch series "btrfs: Convert kmap/memset/kunmap to memzero_user()". Lifting memzero_user(), convert it to kmap_local_page() and then use it in btrfs. This patch (of 3): memzero_page() can replace the kmap/memset/kunmap pattern in other places in the code. While zero_user() has the same interface it is not the same call and its use should be limited and some of those calls may be better converted from zero_user() to memzero_page().[1] But that is not addressed in this series. Lift memzero_page() to highmem. [1] https://lore.kernel.org/lkml/CAHk-=wijdojzo56FzYqE5TOYw2Vws7ik3LEMGj9SPQaJJ+Z73Q@mail.gmail.com/ Link: https://lkml.kernel.org/r/20210309212137.2610186-1-ira.weiny@intel.com Link: https://lkml.kernel.org/r/20210309212137.2610186-2-ira.weiny@intel.comSigned-off-by:
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zhouchuangao authored
It can be optimized at compile time. Link: https://lkml.kernel.org/r/1616727798-9110-1-git-send-email-zhouchuangao@vivo.comSigned-off-by:
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