Re: [KJ] [PATCH] is_power_of_2 in ia64mm

Andreas Schwab
2007-02-16T16:43:44Z

Richard Knutsson <ricknu-0@student.ltu.se> writes:

> Andreas Schwab wrote:
>> Richard Knutsson <ricknu-0@student.ltu.se> writes:
>>
>>> 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?
>>>
>>
>> What else can it mean?
>>
> What about !one_or_less_bit()?

Obviously not.

Andreas.

--
Andreas Schwab, SuSE Labs, schwab@suse.de
SuSE Linux Products GmbH, Maxfeldstraße 5, 90409 Nürnberg, Germany
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