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>,
Joe Perches <joe@perches.com>
Subject: [RESEND PATCH v2 0/6] lib/find_bit: fast path for small bitmaps
Date: Sat, 30 Jan 2021 11:17:11 -0800 [thread overview]
Message-ID: <20210130191719.7085-1-yury.norov@gmail.com> (raw)
Bitmap operations are much simpler and faster in case of small bitmaps
which 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 are small and their 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.
v1: https://www.spinics.net/lists/kernel/msg3804727.html
v2: - employ GENMASK() for bitmaps;
- unify find_bit inliners in;
- address comments to v1;
Yury Norov (8):
tools: disable -Wno-type-limits
tools: bitmap: sync function declarations with linux kernel
arch: rearrange headers inclusion order in asm/bitops for m68k and sh
lib: introduce BITS_{FIRST,LAST} macro
bitsperlong.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 | 47 ++++-------
tools/include/linux/bits.h | 6 ++
tools/lib/bitmap.c | 10 +--
tools/lib/find_bit.c | 56 +++++-------
tools/scripts/Makefile.include | 1 +
tools/testing/radix-tree/bitmap.c | 4 +-
22 files changed, 337 insertions(+), 225 deletions(-)
--
2.25.1
next reply other threads:[~2021-01-30 19:18 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-30 19:17 Yury Norov [this message]
2021-01-30 19:17 ` [PATCH 1/8] tools: disable -Wno-type-limits Yury Norov
2021-01-30 19:17 ` [PATCH 2/8] tools: bitmap: sync function declarations with linux kernel Yury Norov
2021-01-30 19:17 ` [PATCH 3/8] arch: rearrange headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-01-30 19:17 ` [PATCH 4/8] lib: introduce BITS_{FIRST,LAST} macro Yury Norov
2021-02-01 13:42 ` Andy Shevchenko
2021-01-30 19:17 ` [PATCH 5/8] bitsperlong.h: introduce SMALL_CONST() macro Yury Norov
2021-02-01 13:45 ` Andy Shevchenko
2021-02-02 7:10 ` Yury Norov
2021-01-30 19:17 ` [PATCH 6/8] lib: inline _find_next_bit() wrappers Yury Norov
2021-02-01 13:47 ` Andy Shevchenko
2021-02-02 7:13 ` Yury Norov
2021-01-30 19:17 ` [PATCH 7/8] lib: add fast path for find_next_*_bit() Yury Norov
2021-02-01 13:49 ` Andy Shevchenko
2021-02-01 16:02 ` David Laight
2021-02-01 16:22 ` 'Andy Shevchenko'
2021-02-02 7:02 ` Yury Norov
2021-01-30 19:17 ` [PATCH 8/8] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-02-01 13:50 ` Andy Shevchenko
2021-02-15 21:30 ` [RESEND PATCH v2 0/6] lib/find_bit: fast path for small bitmaps Yury Norov
2021-02-16 9:14 ` Andy Shevchenko
2021-02-16 18:00 ` Yury Norov
2021-02-17 10:33 ` Andy Shevchenko
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