Ming Lei wrote, on 04/18/2014 17:47:
> On Fri, Apr 18, 2014 at 3:03 AM, Jörg-Volker Peetz <jvpe...@web.de> wrote:
>> Ming Lei wrote, on 04/17/2014 17:49:
>>> Signed-off-by: Ming Lei <tom.leim...@gmail.com>
>>> ---
>>> block/blk-mq.c | 7 +------
>>> 1 file changed, 1 insertion(+), 6 deletions(-)
>>>
>>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>>> index baff2d0..1eff3d9 100644
>>> --- a/block/blk-mq.c
>>> +++ b/block/blk-mq.c
>>> @@ -1130,12 +1130,7 @@ static void blk_mq_free_rq_map(struct blk_mq_tag_set
>>> *set,
>>>
>>> static size_t order_to_size(unsigned int order)
>>> {
>>> - size_t ret = PAGE_SIZE;
>>> -
>>> - while (order--)
>>> - ret *= 2;
>>> -
>>> - return ret;
>>> + return (1 << order) * PAGE_SIZE;
>>
>> Shouldn't this be
>>
>> return ((size_t)1 << order) * PAGE_SIZE;
>>
>> ?
>
> IMO, it isn't necessary since compiler will cast type
> of 1 and the expression to size_t automatically.
>
>
> Thanks,
Testing this with gcc 4.8.2 with order > 30 confirms that the automatic casting
is done operator-wise and the explicit casting is necessary.
Regards,
jvp.
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