Christophe Leroy [off-list ref] writes:
 +	if ((start + len) > SLICE_LOW_TOP) {

+		unsigned long start_index = GET_HIGH_SLICE_INDEX(start);
+		unsigned long align_end = ALIGN(end, (1UL << SLICE_HIGH_SHIFT));
+		unsigned long count = GET_HIGH_SLICE_INDEX(align_end) - start_index;
+		unsigned long i;
 
-	slice_bitmap_and(result, mask->high_slices, available->high_slices,
-			 slice_count);
+		for (i = start_index; i < start_index + count; i++) {
+			if (!test_bit(i, available->high_slices))
+				return false;
+		}
+	}

why not bitmap_equal here instead of test_bit in loop?

 
-	return (mask->low_slices & available->low_slices) == mask->low_slices &&
-		slice_bitmap_equal(result, mask->high_slices, slice_count);
+	return true;
 }

-aneesh