Messages in this thread | | | Subject | Re: [RFC] mm: Change the data type of huge page size from unsigned long to u64 | From | Rui Teng <> | Date | Tue, 13 Sep 2016 19:21:07 +0800 |
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On 9/13/16 5:32 PM, Kirill A. Shutemov wrote: > On Tue, Sep 13, 2016 at 05:26:05PM +0800, Rui Teng wrote: >> The huge page size could be 16G(0x400000000) on ppc64 architecture, and it will >> cause an overflow on unsigned long data type(0xFFFFFFFF). > > Huh? ppc64 is 64-bit system and sizeof(void *) is equal to > sizeof(unsigned long) on Linux (LP64 model). > > So where your 0xFFFFFFFF comes from? > The size of unsigned long data type is 4 bytes, and the 0xFFFFFFFF here is the maximum value. And 16G is bigger than it.
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