On 2015/08/03 18:44, Alexander Shishkin wrote: > On 3 August 2015 at 12:08, Peter Zijlstra <[email protected]> wrote: >> On Mon, Aug 03, 2015 at 12:03:13PM +0300, Alexander Shishkin wrote: >>> Takao Indoh <[email protected]> writes: >> >>> Even though TOPA_SHIFT happens to be the same as PAGE_SHIFT, it is a >>> property of a separate hardware block, not mmu. PAGE_SHIFT is 12, but >>> 12 is not always PAGE_SHIFT. >> >> PAGE_SHIFT is _always_ 12 on x86. Changing that will require changing >> the page table format, a rather unlikely thing to go happen. > > Of course. Yet that doesn't justify turning every 12 into PAGE_SHIFT > is what I'm saying. > > Oh, look, it's PAGE_SHIFT o'clock on x86, time for lunch. :)
I thought the base address of output region is page aligned. I took a look at Intel SDM again, it just says the base address is 4K-aligned physical address, does not mention page size. So, logically TOPA_SHIFT and PAGE_SHIFT are different things and I'll remove this change in next version. Thanks, Takao Indoh > > Regards, > -- > Alex > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
