Re: [Qemu-devel] [PATCH v3 1/2] bitmap: get last word mask from nr directly

[Paolo Bonzini]

On 21/07/19 02:33, Wei Yang wrote:
> On Thu, Jul 18, 2019 at 09:04:55AM +0800, Wei Yang wrote:
>> The value left in nr is the number of bits for the last word, which
>> could be calculate the last word mask directly.
>>
>> Remove the unnecessary size.
>>
> 
> May I ask why Patch 2 is picked up, but this one is not?

Tests are always good to have, this cleanup will wait for 4.2 but it's
in the queue.

Paolo

>> Signed-off-by: Wei Yang <address@hidden>
>>
>> ---
>> v2: refine bitmap_set_atomic too, suggested from Peter
>> ---
>> util/bitmap.c | 9 +++------
>> 1 file changed, 3 insertions(+), 6 deletions(-)
>>
>> diff --git a/util/bitmap.c b/util/bitmap.c
>> index 1753ff7f5b..5b15249796 100644
>> --- a/util/bitmap.c
>> +++ b/util/bitmap.c
>> @@ -160,7 +160,6 @@ int slow_bitmap_andnot(unsigned long *dst, const 
>> unsigned long *bitmap1,
>> void bitmap_set(unsigned long *map, long start, long nr)
>> {
>>     unsigned long *p = map + BIT_WORD(start);
>> -    const long size = start + nr;
>>     int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
>>     unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
>>
>> @@ -174,7 +173,7 @@ void bitmap_set(unsigned long *map, long start, long nr)
>>         p++;
>>     }
>>     if (nr) {
>> -        mask_to_set &= BITMAP_LAST_WORD_MASK(size);
>> +        mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
>>         *p |= mask_to_set;
>>     }
>> }
>> @@ -182,7 +181,6 @@ void bitmap_set(unsigned long *map, long start, long nr)
>> void bitmap_set_atomic(unsigned long *map, long start, long nr)
>> {
>>     unsigned long *p = map + BIT_WORD(start);
>> -    const long size = start + nr;
>>     int bits_to_set = BITS_PER_LONG - (start % BITS_PER_LONG);
>>     unsigned long mask_to_set = BITMAP_FIRST_WORD_MASK(start);
>>
>> @@ -208,7 +206,7 @@ void bitmap_set_atomic(unsigned long *map, long start, 
>> long nr)
>>
>>     /* Last word */
>>     if (nr) {
>> -        mask_to_set &= BITMAP_LAST_WORD_MASK(size);
>> +        mask_to_set &= BITMAP_LAST_WORD_MASK(nr);
>>         atomic_or(p, mask_to_set);
>>     } else {
>>         /* If we avoided the full barrier in atomic_or(), issue a
>> @@ -221,7 +219,6 @@ void bitmap_set_atomic(unsigned long *map, long start, 
>> long nr)
>> void bitmap_clear(unsigned long *map, long start, long nr)
>> {
>>     unsigned long *p = map + BIT_WORD(start);
>> -    const long size = start + nr;
>>     int bits_to_clear = BITS_PER_LONG - (start % BITS_PER_LONG);
>>     unsigned long mask_to_clear = BITMAP_FIRST_WORD_MASK(start);
>>
>> @@ -235,7 +232,7 @@ void bitmap_clear(unsigned long *map, long start, long 
>> nr)
>>         p++;
>>     }
>>     if (nr) {
>> -        mask_to_clear &= BITMAP_LAST_WORD_MASK(size);
>> +        mask_to_clear &= BITMAP_LAST_WORD_MASK(nr);
>>         *p &= ~mask_to_clear;
>>     }
>> }
>> -- 
>> 2.17.1
>>
>