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From: Rasmus Villemoes <linux@rasmusvillemoes.dk>
To: Andrew Morton <akpm@linux-foundation.org>,
	Yury Norov <ynorov@caviumnetworks.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Rasmus Villemoes <linux@rasmusvillemoes.dk>,
	linux-kernel@vger.kernel.org
Subject: [PATCH 5/7] linux/bitmap.h: relax comment on compile-time constant nbits
Date: Sat, 18 Aug 2018 15:16:21 +0200
Message-ID: <20180818131623.8755-6-linux@rasmusvillemoes.dk> (raw)
In-Reply-To: <20180818131623.8755-1-linux@rasmusvillemoes.dk>

It's not clear what's so horrible about emitting a function call to
handle a run-time sized bitmap. Moreover, gcc also emits a function call
for a compile-time-constant-but-huge nbits, so the comment isn't even
accurate.

Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
---
 include/linux/bitmap.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/bitmap.h b/include/linux/bitmap.h
index e34c361f4a92..3f0cac3aedca 100644
--- a/include/linux/bitmap.h
+++ b/include/linux/bitmap.h
@@ -28,8 +28,8 @@
  * The available bitmap operations and their rough meaning in the
  * case that the bitmap is a single unsigned long are thus:
  *
- * Note that nbits should be always a compile time evaluable constant.
- * Otherwise many inlines will generate horrible code.
+ * The generated code is more efficient when nbits is known at
+ * compile-time and at most BITS_PER_LONG.
  *
  * ::
  *
-- 
2.16.4


  parent reply index

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-18 13:16 [PATCH 0/7] assorted minor bitmap patches Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 1/7] lib/bitmap.c: remove wrong documentation Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 2/7] linux/bitmap.h: handle constant zero-size bitmaps correctly Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 3/7] linux/bitmap.h: remove redundant uses of small_const_nbits() Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 4/7] linux/bitmap.h: fix type of nbits in bitmap_shift_right() Rasmus Villemoes
2018-08-18 13:16 ` Rasmus Villemoes [this message]
2018-09-04 11:08   ` [PATCH 5/7] linux/bitmap.h: relax comment on compile-time constant nbits Yury Norov
2018-09-04 11:30     ` Andy Shevchenko
2018-09-04 11:45       ` Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 6/7] lib/bitmap.c: fix remaining space computation in bitmap_print_to_pagebuf Rasmus Villemoes
2018-08-19 12:37   ` Andy Shevchenko
2018-08-20  7:36     ` Rasmus Villemoes
2018-08-18 13:16 ` [PATCH 7/7] lib/bitmap.c: simplify bitmap_print_to_pagebuf Rasmus Villemoes
2018-08-19 12:39 ` [PATCH 0/7] assorted minor bitmap patches Andy Shevchenko

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