Re: [KJ] [PATCH] is_power_of_2 in ia64mm

Richard Knutsson
2007-02-16T15:58:10Z

Andreas Schwab wrote:
> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>
>
>> Vignesh Babu BM wrote:
>>
>>> @@ -175,7 +176,7 @@ static int __init hugetlb_setup_sz(char *str)
>>> tr_pages = 0x15557000UL;
>>> size = memparse(str, &str);
>>> - if (*str || (size & (size-1)) || !(tr_pages & size) ||
>>> + if (*str || !is_power_of_2(size) || !(tr_pages & size) ||
>>> size <= PAGE_SIZE ||
>>> size >= (1UL << PAGE_SHIFT << MAX_ORDER)) {
>>> printk(KERN_WARNING "Invalid huge page size specified\n");
>>>
>>>
>>>
>> As we talked about before; is this really correct? !is_power_of_2(0) ==
>> true while (0 & (0-1)) == 0.
>>
>
> size == 0 is also covered by the next two conditions, so the overall value
> does not change.
>
Yes, but is it meant to state that 'size' is not a power of two?
Otherwise, imho, it should be left as-is.

Richard Knutsson