The patch titled
Subject: lib/bitmap.c: simplify bitmap_pos_to_ord
has been added to the -mm tree. Its filename is
lib-bitmap-simplify-bitmap_pos_to_ord.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/lib-bitmap-simplify-bitmap_pos_to_ord.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/lib-bitmap-simplify-bitmap_pos_to_ord.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/SubmitChecklist when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Subject: lib/bitmap.c: simplify bitmap_pos_to_ord
The ordinal of a set bit is simply the number of set bits before it;
counting those doesn't need to be done one bit at a time. While at it,
update the parameters to unsigned int.
It is not completely unthinkable that gcc would see pos as compile-time
constant 0 in one of the uses of bitmap_pos_to_ord. Since the static
inline frontend bitmap_weight doesn't handle nbits==0 correctly (it would
behave exactly as if nbits==BITS_PER_LONG), use __bitmap_weight.
Alternatively, the last line could be spelled bitmap_weight(buf, pos+1)-1,
but this is simpler.
Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
lib/bitmap.c | 22 ++++++----------------
1 file changed, 6 insertions(+), 16 deletions(-)
diff -puN lib/bitmap.c~lib-bitmap-simplify-bitmap_pos_to_ord lib/bitmap.c
--- a/lib/bitmap.c~lib-bitmap-simplify-bitmap_pos_to_ord
+++ a/lib/bitmap.c
@@ -744,10 +744,10 @@ EXPORT_SYMBOL(bitmap_parselist_user);
/**
* bitmap_pos_to_ord - find ordinal of set bit at given position in bitmap
* @buf: pointer to a bitmap
- * @pos: a bit position in @buf (0 <= @pos < @bits)
- * @bits: number of valid bit positions in @buf
+ * @pos: a bit position in @buf (0 <= @pos < @nbits)
+ * @nbits: number of valid bit positions in @buf
*
- * Map the bit at position @pos in @buf (of length @bits) to the
+ * Map the bit at position @pos in @buf (of length @nbits) to the
* ordinal of which set bit it is. If it is not set or if @pos
* is not a valid bit position, map to -1.
*
@@ -759,22 +759,12 @@ EXPORT_SYMBOL(bitmap_parselist_user);
*
* The bit positions 0 through @bits are valid positions in @buf.
*/
-static int bitmap_pos_to_ord(const unsigned long *buf, int pos, int bits)
+static int bitmap_pos_to_ord(const unsigned long *buf, unsigned int pos, unsigned int nbits)
{
- int i, ord;
-
- if (pos < 0 || pos >= bits || !test_bit(pos, buf))
+ if (pos >= nbits || !test_bit(pos, buf))
return -1;
- i = find_first_bit(buf, bits);
- ord = 0;
- while (i < pos) {
- i = find_next_bit(buf, bits, i + 1);
- ord++;
- }
- BUG_ON(i != pos);
-
- return ord;
+ return __bitmap_weight(buf, pos);
}
/**
_
Patches currently in -mm which might be from linux@xxxxxxxxxxxxxxxxxx are
origin.patch
lib-string_get_size-remove-redundant-prefixes.patch
lib-string_get_size-use-32-bit-arithmetic-when-possible.patch
lib-string_get_size-return-void.patch
lib-bitmap-more-signed-unsigned-conversions.patch
linux-nodemaskh-update-bitmap-wrappers-to-take-unsigned-int.patch
linux-cpumaskh-update-bitmap-wrappers-to-take-unsigned-int.patch
lib-bitmap-update-bitmap_onto-to-unsigned.patch
lib-bitmap-change-parameters-of-bitmap_fold-to-unsigned.patch
lib-bitmap-simplify-bitmap_pos_to_ord.patch
lib-bitmap-simplify-bitmap_ord_to_pos.patch
lib-bitmap-make-the-bits-parameter-of-bitmap_remap-unsigned.patch
checkpatch-emit-an-error-when-using-predefined-timestamp-macros.patch
--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
