On Thu, Aug 19, 2010 at 06:40:17AM -0600, Matthew Wilcox wrote: > On Thu, Aug 19, 2010 at 02:23:09PM +0200, Andi Kleen wrote: > > IMHO it would be better to simply disable the warning in sparse instead > > of uglying the code just to work around sparse bogosity. It doesnt' seem > > to make much sense. A subtraction followed by a shift is not expensive. > > What makes you think it's a shift? struct page isn't necessarily a > power of two in size. The original poster said "allyesconfig" which is > going to add in KMEMCHECK and WANT_PAGE_DEBUG_FLAGS. I think that makes > it 76 bytes on x86-32, so sparse is right to warn. These can be still implemented cheaply. Small constants generally are The only thing that would be really expensive is division by unknown number. -Andi -- ak@xxxxxxxxxxxxxxx -- Speaking for myself only. -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
