From: Yury Norov <yury.norov@gmail.com>
To: linux-kernel@vger.kernel.org
Cc: Yury Norov <yury.norov@gmail.com>,
linux-m68k@lists.linux-m68k.org, linux-arch@vger.kernel.org,
linux-sh@vger.kernel.org, Alexey Klimov <aklimov@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Arnd Bergmann <arnd@arndb.de>, David Sterba <dsterba@suse.com>,
Dennis Zhou <dennis@kernel.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Jianpeng Ma <jianpeng.ma@intel.com>,
Joe Perches <joe@perches.com>,
John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>,
Rich Felker <dalias@libc.org>,
Stefano Brivio <sbrivio@redhat.com>,
Wei Yang <richard.weiyang@linux.alibaba.com>,
Wolfram Sang <wsa+renesas@sang-engineering.com>,
Yoshinori Sato <ysato@users.sourceforge.jp>
Subject: [PATCH 06/13] lib: extend the scope of small_const_nbits() macro
Date: Mon, 15 Mar 2021 18:54:17 -0700 [thread overview]
Message-ID: <20210316015424.1999082-7-yury.norov@gmail.com> (raw)
In-Reply-To: <20210316015424.1999082-1-yury.norov@gmail.com>
find_bit would also benefit from small_const_nbits() optimizations.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
include/asm-generic/bitsperlong.h | 9 +++++++++
include/linux/bitmap.h | 3 ---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/include/asm-generic/bitsperlong.h b/include/asm-generic/bitsperlong.h
index 3905c1c93dc2..96032f4f908f 100644
--- a/include/asm-generic/bitsperlong.h
+++ b/include/asm-generic/bitsperlong.h
@@ -23,4 +23,13 @@
#define BITS_PER_LONG_LONG 64
#endif
+#define SMALL_CONST(n) (__builtin_constant_p(n) && (unsigned long)(n) < BITS_PER_LONG)
+
+/*
+ * The valid number of bits for a bitmap to be small enough, or in other words,
+ * fit into a single machine word is 1 to BITS_PER_LONG inclusively. 0 is not a
+ * valid number for size, and most probably a sing of error.
+ */
+#define small_const_nbits(n) SMALL_CONST((n) - 1)
+
#endif /* __ASM_GENERIC_BITS_PER_LONG */
diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index adf7bd9f0467..bc13a890ecc1 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -224,9 +224,6 @@ extern int bitmap_print_to_pagebuf(bool list, char *buf,
* so make such users (should any ever turn up) call the out-of-line
* versions.
*/
-#define small_const_nbits(nbits) \
- (__builtin_constant_p(nbits) && (nbits) <= BITS_PER_LONG && (nbits) > 0)
-
static inline void bitmap_zero(unsigned long *dst, unsigned int nbits)
{
unsigned int len = BITS_TO_LONGS(nbits) * sizeof(unsigned long);
--
2.25.1
next prev parent reply other threads:[~2021-03-16 1:55 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-16 1:54 [PATCH v4 00/13] lib/find_bit: fast path for small bitmaps Yury Norov
2021-03-16 1:54 ` [PATCH 01/13] tools: disable -Wno-type-limits Yury Norov
2021-03-16 8:17 ` Rasmus Villemoes
2021-03-16 11:39 ` Andy Shevchenko
2021-03-16 1:54 ` [PATCH 02/13] tools: bitmap: sync function declarations with the kernel Yury Norov
2021-03-16 8:18 ` Rasmus Villemoes
2021-03-16 1:54 ` [PATCH 03/13] arch: rearrange headers inclusion order in asm/bitops for m68k and sh Yury Norov
2021-03-16 1:54 ` [PATCH 04/13] lib: introduce BITS_{FIRST,LAST} macro Yury Norov
2021-03-16 8:35 ` Rasmus Villemoes
2021-03-16 11:42 ` Andy Shevchenko
2021-03-17 5:40 ` Yury Norov
2021-03-17 19:58 ` Rasmus Villemoes
2021-03-17 23:33 ` Yury Norov
2021-03-16 1:54 ` [PATCH 05/13] tools: sync BITS_MASK macros with the kernel Yury Norov
2021-03-16 1:54 ` Yury Norov [this message]
2021-03-16 8:56 ` [PATCH 06/13] lib: extend the scope of small_const_nbits() macro Rasmus Villemoes
2021-03-17 4:53 ` Yury Norov
2021-03-16 1:54 ` [PATCH 07/13] tools: sync small_const_nbits() macro with the kernel Yury Norov
2021-03-16 1:54 ` [PATCH 08/13] lib: inline _find_next_bit() wrappers Yury Norov
2021-03-16 1:54 ` [PATCH 09/13] tools: sync find_next_bit implementation Yury Norov
2021-03-16 1:54 ` [PATCH 10/13] lib: add fast path for find_next_*_bit() Yury Norov
2021-03-16 1:54 ` [PATCH 11/13] lib: add fast path for find_first_*_bit() and find_last_bit() Yury Norov
2021-04-06 16:03 ` Guenter Roeck
2021-04-06 18:15 ` Yury Norov
2021-03-16 1:54 ` [PATCH 12/13] tools: sync lib/find_bit implementation Yury Norov
2021-03-16 1:54 ` [PATCH 13/13] MAINTAINERS: Add entry for the bitmap API Yury Norov
2021-03-16 11:45 ` Andy Shevchenko
2021-03-17 4:47 ` Yury Norov
2021-03-17 4:57 ` Joe Perches
2021-03-17 6:40 ` Lukas Bulwahn
2021-03-17 19:29 ` Yury Norov
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210316015424.1999082-7-yury.norov@gmail.com \
--to=yury.norov@gmail.com \
--cc=aklimov@redhat.com \
--cc=akpm@linux-foundation.org \
--cc=andriy.shevchenko@linux.intel.com \
--cc=arnd@arndb.de \
--cc=dalias@libc.org \
--cc=dennis@kernel.org \
--cc=dsterba@suse.com \
--cc=geert@linux-m68k.org \
--cc=glaubitz@physik.fu-berlin.de \
--cc=jianpeng.ma@intel.com \
--cc=joe@perches.com \
--cc=jpoimboe@redhat.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-m68k@lists.linux-m68k.org \
--cc=linux-sh@vger.kernel.org \
--cc=linux@rasmusvillemoes.dk \
--cc=richard.weiyang@linux.alibaba.com \
--cc=sbrivio@redhat.com \
--cc=wsa+renesas@sang-engineering.com \
--cc=ysato@users.sourceforge.jp \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).