On 02/10/2010 11:55 AM, OHMURA Kei wrote:
>
>> Instead of using a nested loop if bitmap_ul[i] != 0, it is possible to
>> use just a single loop (while (c> 0)), and process a long's worth of data.
>>
>> The only trickery is with big endian hosts, where the conversion from
>> bit number to page number is a bit complicated.
>>
> To convert the bitmap from big endian to little endian, le_bswap macro in
> bswap.h seems useful, which is now undefined. What do you think about this
> approach?
>
> This is an example bitmap-traveling code using le_bswap:
> /*
> * bitmap-traveling is faster than memory-traveling (for addr...)
> * especially when most of the memory is not dirty.
> */
> for (i = 0; i < len; i++) {
> if (bitmap_ul[i] != 0) {
> c = le_bswap(bitmap_ul[i], HOST_LONG_BITS);
> while (c > 0) {
> j = ffsl(c) - 1;
> c &= ~(1ul << j);
> page_number = i * HOST_LONG_BITS + j;
> addr1 = page_number * TARGET_PAGE_SIZE;
> addr = offset + addr1;
> ram_addr = cpu_get_physical_page_desc(addr);
> cpu_physical_memory_set_dirty(ram_addr);
> }
> }
> }
>
Yes, that solves the problem very neatly.
--
error compiling committee.c: too many arguments to function
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