Le vendredi 29 juillet 2011 à 16:18 -0700, Andi Kleen a écrit : > Christoph Lameter <cl@xxxxxxxxx> writes: > > > On Fri, 29 Jul 2011, Pekka Enberg wrote: > > > >> We haven't come up with a solution to keep struct page size the same but I > >> think it's a reasonable trade-off. > > > > The change requires the page struct to be aligned to a double word > > boundary. > > Why is that? > Because cmpxchg16b is believed to require a 16bytes alignment. http://siyobik.info/main/reference/instruction/CMPXCHG8B%2FCMPXCHG16B 64-Bit Mode Exceptions ... #GP(0) If the memory address is in a non-canonical form. If memory operand for CMPXCHG16B is not aligned on a 16-byte boundary. If CPUID.01H:ECX.CMPXCHG16B[bit 13] = 0. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>