On Thu, 24 Mar 2005, Nick Piggin wrote: > > OK, attached is my first cut at slimming down the boundary tests. > I have only had a chance to try it on i386, so I hate to drop it > on you like this - but I *have* put a bit of thought into it.... > Treat it as an RFC, and I'll try to test it on a wider range of > things in the next couple of days.
I've stared and stared at it. I think I mostly like it. It's nicer to be rounding end up than ceiling down. It's clearly superior to what David and I had, in branching less (other than in your BUG_ONs), and I do believe your "if (end - ceiling - 1 < P*_SIZE - 1)" is correct and efficient. But I still find it harder to understand than ours; and don't understand at all your comment "end can't have approached ceiling from above...." - but I think you're bravely trying to explain the case I sidestepped with a lordly unexplained "end can't go down to 0 there". Let others decide. One thing I believe is outright wrong, at least with out-of-tree patches: your change from "if (addr > end - 1)" to "if (addr >= end)", after you've just rounded up end (perhaps to 0). (And let me astonish you by asking for the blank lines back before pmd_offset and pud_offset!) Hugh - 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/
