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>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Subject: [PATCH 0/6] lib/find_bit: fast path for small bitmaps
Date: Fri, 29 Jan 2021 12:45:22 -0800 [thread overview]
Message-ID: <20210129204528.2118168-1-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_*_bit() API lacks this functionality; despite users will benefit from it
a lot. One important example is cpumask subsystem, when 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.
Tools is synchronized with new implementation where needed.
Yury Norov (6):
arch: rearrange headers inclusion order in asm/bitops for m68k and sh
lib: inttroduce BITS_{FIRST,LAST}() macro
bits_per_long.h: introduce SMALL_CONST() macro
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 | 108 +++++++++++++++++++++---
include/asm-generic/bitops/le.h | 38 ++++++++-
include/asm-generic/bitsperlong.h | 2 +
include/linux/bitmap.h | 60 ++++++-------
include/linux/bitops.h | 12 ---
include/linux/bits.h | 6 ++
include/linux/cpumask.h | 8 +-
include/linux/netdev_features.h | 2 +-
include/linux/nodemask.h | 2 +-
lib/bitmap.c | 26 +++---
lib/find_bit.c | 72 +++-------------
lib/genalloc.c | 8 +-
tools/include/asm-generic/bitops/find.h | 85 +++++++++++++++++--
tools/include/asm-generic/bitsperlong.h | 2 +
tools/include/linux/bitmap.h | 39 +++------
tools/include/linux/bits.h | 6 ++
tools/lib/bitmap.c | 6 +-
tools/lib/find_bit.c | 56 +++++-------
tools/testing/radix-tree/bitmap.c | 4 +-
21 files changed, 330 insertions(+), 219 deletions(-)
--
2.25.1
next reply other threads:[~2021-01-29 20:46 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-29 20:45 Yury Norov [this message]
2021-01-29 20:45 ` [PATCH 1/6] arch: rearrange headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-01-29 20:45 ` [PATCH 2/6] lib: inttroduce BITS_{FIRST,LAST}() macro Yury Norov
2021-01-29 20:45 ` [PATCH 2/5] bits_per_long.h: introduce SMALL_CONST() macro Yury Norov
2021-01-29 21:10 ` Andy Shevchenko
2021-01-29 21:24 ` Joe Perches
2021-01-29 21:28 ` Yury Norov
2021-01-29 22:25 ` Yury Norov
2021-01-29 20:45 ` [PATCH 3/5] lib: inline _find_next_bit() wrappers Yury Norov
2021-01-29 20:45 ` [PATCH 4/5] lib: add fast path for find_next_*_bit() Yury Norov
2021-01-29 20:45 ` [PATCH 6/6] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-01-29 20:51 ` [PATCH 0/6] lib/find_bit: fast path for small bitmaps Yury Norov
2021-01-29 21:12 ` Andy Shevchenko
-- strict thread matches above, loose matches on Subject: below --
2021-01-21 0:06 Yury Norov
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