From: Yury Norov <yury.norov@gmail.com>
To: linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org,
linux-sh@vger.kernel.org, linux-arch@vger.kernel.org
Cc: Yury Norov <yury.norov@gmail.com>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Yoshinori Sato <ysato@users.sourceforge.jp>,
Rich Felker <dalias@libc.org>, Arnd Bergmann <arnd@arndb.de>,
Dennis Zhou <dennis@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
David Sterba <dsterba@suse.com>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Stefano Brivio <sbrivio@redhat.com>,
"Ma, Jianpeng" <jianpeng.ma@intel.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Subject: [PATCH 0/6] lib/find_bit: fast path for small bitmaps
Date: Wed, 20 Jan 2021 16:06:24 -0800 [thread overview]
Message-ID: <20210121000630.371883-1-yury.norov@gmail.com> (raw)
Bitmap operations are much simpler and faster in case of small bitmaps,
whicn fit into a single word. In linux/bitmap.h we have a machinery that
allows compiler to replace actual function call with a few instructions
if bitmaps passed into the function is small and its size is known at
compile time.
find_next_*_bit() lacks this functionality; despite users will
benefit from it a lot. One important example is cpumask subsystem if
NR_CPUS <= BITS_PER_LONG. In the very best case, the compiler may replace
a find_*_bit() call for such a bitmap with a single ffs or ffz instruction.
Yury Norov (6):
arch: rearrahge headers inclusion order in asm/bitops for m68k and sh
bitmap: move some macros from linux/bitmap.h to linux/bitops.h
tools: sync bitops macro definitions with the kernel
lib: inline _find_next_bit() wrappers
lib: add fast path for find_next_*_bit()
lib: add fast path for find_first_*_bit() and find_last_bit()
arch/m68k/include/asm/bitops.h | 4 +-
arch/sh/include/asm/bitops.h | 3 +-
include/asm-generic/bitops/find.h | 123 +++++++++++++++++++++++++++---
include/asm-generic/bitops/le.h | 45 ++++++++++-
include/linux/bitmap.h | 11 ---
include/linux/bitops.h | 23 +++---
lib/find_bit.c | 68 ++---------------
tools/include/linux/bitmap.h | 11 ---
tools/include/linux/bitops.h | 11 +++
9 files changed, 188 insertions(+), 111 deletions(-)
--
2.25.1
next reply other threads:[~2021-01-21 1:43 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-21 0:06 Yury Norov [this message]
2021-01-21 0:06 ` [PATCH 1/6] arch: rearrahge headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-01-21 8:03 ` Geert Uytterhoeven
2021-01-21 8:47 ` John Paul Adrian Glaubitz
2021-01-21 0:06 ` [PATCH 2/6] bitmap: move some macros from linux/bitmap.h to linux/bitops.h Yury Norov
2021-01-21 10:19 ` Andy Shevchenko
2021-01-21 20:38 ` Yury Norov
2021-01-21 0:06 ` [PATCH 3/6] tools: sync bitops macro definitions with the kernel Yury Norov
2021-01-21 10:23 ` Andy Shevchenko
2021-01-21 0:06 ` [PATCH 4/6] lib: inline _find_next_bit() wrappers Yury Norov
2021-01-21 10:28 ` Andy Shevchenko
2021-01-29 6:41 ` Yury Norov
2021-01-21 0:06 ` [PATCH 5/6] lib: add fast path for find_next_*_bit() Yury Norov
2021-01-21 10:34 ` Andy Shevchenko
2021-01-21 0:06 ` [PATCH 6/6] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-01-21 10:40 ` Andy Shevchenko
2021-01-29 20:45 [PATCH 0/6] lib/find_bit: fast path for small bitmaps Yury Norov
2021-01-29 20:51 ` Yury Norov
2021-01-29 21:12 ` Andy Shevchenko
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