The patch titled bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area fix has been added to the -mm tree. Its filename is bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area-fix.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 *** See http://userweb.kernel.org/~akpm/stuff/added-to-mm.txt to find out what to do about this The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area fix From: Akinobu Mita <akinobu.mita@xxxxxxxxx> - Rewrite bitmap_set and bitmap_clear Instead of setting or clearing for each bit. - Fix off-by-one errors in bitmap_find_next_zero_area This bug was derived from find_next_zero_area in iommu-helper. - Add kerneldoc for bitmap_find_next_zero_area This patch is supposed to be folded into bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area.patch * -v2 - Remove an extra test at the "index" value by find_next_bit Index was just returned by find_next_zero_bit, so we know it's zero. Noticed-by: Kyle Hubert <khubert@xxxxxxxxx> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx> Cc: FUJITA Tomonori <fujita.tomonori@xxxxxxxxxxxxx> Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> Cc: Paul Mackerras <paulus@xxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Greg Kroah-Hartman <gregkh@xxxxxxx> Cc: Lothar Wassmann <LW@xxxxxxxxxxxxxxxxxxx> Cc: Roland Dreier <rolandd@xxxxxxxxx> Cc: Yevgeny Petrilin <yevgenyp@xxxxxxxxxxxxxx> Cc: Tony Luck <tony.luck@xxxxxxxxx> Cc: Fenghua Yu <fenghua.yu@xxxxxxxxx> Cc: Joerg Roedel <joerg.roedel@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- diff -puN lib/bitmap.c~bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area-fix lib/bitmap.c --- a/lib/bitmap.c~bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area-fix +++ a/lib/bitmap.c @@ -271,28 +271,62 @@ int __bitmap_weight(const unsigned long } EXPORT_SYMBOL(__bitmap_weight); -void bitmap_set(unsigned long *map, int i, int len) -{ - int end = i + len; +#define BITMAP_FIRST_WORD_MASK(start) (~0UL << ((start) % BITS_PER_LONG)) - while (i < end) { - __set_bit(i, map); - i++; +void bitmap_set(unsigned long *map, int start, int nr) +{ + unsigned long *p = map + BIT_WORD(start); + const int size = start + nr; + int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start); + + while (nr - bits_to_set >= 0) { + *p |= mask_to_set; + nr -= bits_to_set; + bits_to_set = BITS_PER_LONG; + mask_to_set = ~0UL; + p++; + } + if (nr) { + mask_to_set &= BITMAP_LAST_WORD_MASK(size); + *p |= mask_to_set; } } EXPORT_SYMBOL(bitmap_set); void bitmap_clear(unsigned long *map, int start, int nr) { - int end = start + nr; - - while (start < end) { - __clear_bit(start, map); - start++; + unsigned long *p = map + BIT_WORD(start); + const int size = start + nr; + int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG); + unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start); + + while (nr - bits_to_clear >= 0) { + *p &= ~mask_to_clear; + nr -= bits_to_clear; + bits_to_clear = BITS_PER_LONG; + mask_to_clear = ~0UL; + p++; + } + if (nr) { + mask_to_clear &= BITMAP_LAST_WORD_MASK(size); + *p &= ~mask_to_clear; } } EXPORT_SYMBOL(bitmap_clear); +/* + * bitmap_find_next_zero_area - find a contiguous aligned zero area + * @map: The address to base the search on + * @size: The bitmap size in bits + * @start: The bitnumber to start searching at + * @nr: The number of zeroed bits we're looking for + * @align_mask: Alignment mask for zero area + * + * The @align_mask should be one less than a power of 2; the effect is that + * the bit offset of all zero areas this function finds is multiples of that + * power of 2. A @align_mask of 0 means no alignment is required. + */ unsigned long bitmap_find_next_zero_area(unsigned long *map, unsigned long size, unsigned long start, @@ -304,12 +338,12 @@ again: index = find_next_zero_bit(map, size, start); /* Align allocation */ - index = (index + align_mask) & ~align_mask; + index = __ALIGN_MASK(index, align_mask); end = index + nr; - if (end >= size) + if (end > size) return end; - i = find_next_bit(map, end, index); + i = find_next_bit(map, end, index + 1); if (i < end) { start = i + 1; goto again; _ Patches currently in -mm which might be from akinobu.mita@xxxxxxxxx are lib-iommu-helperc-fix-off-by-one-error-in-find_next_zero_area.patch iommu-helper-simplify-find_next_zero_area.patch bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area.patch bitmap-introduce-bitmap_set-bitmap_clear-bitmap_find_next_zero_area-fix.patch iommu-helper-use-bitmap-library.patch isp1362-hcd-use-bitmap_find_next_zero_area.patch mlx4-use-bitmap_find_next_zero_area.patch sparc-use-bitmap_find_next_zero_area.patch ia64-use-bitmap_find_next_zero_area.patch genalloc-use-bitmap_find_next_zero_area.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