Re: [BUG 2.6.31-rc1] HIGHMEM64G causes hang in PCI init on 32-bit x86

H. Peter Anvin
2009-06-30T22:56:34Z

Yinghai Lu wrote:
>>>
>>> Not very well tested, but it _looks_ correct, and uses Peter's trick, and
>>> willlet the compiler notice that
>>>
>>> round_up(x,y)-1
>>>
>>> is the same thing as
>>>
>>> x | (y-1)
>>>
>>> which it _could_ have perhaps figured out before, but now it's way more
>>> obvious.
>> how about x = 0, y = 0x100?
>>
>
> also x=0x100000, and y=0x100?
>

Yes, it doesn't work when x is already aligned.

-hpa