On Thu, Jan 17, 2008 at 11:15:05PM +0100, Ingo Molnar wrote: > > * Andreas Herrmann3 <[EMAIL PROTECTED]> wrote: > > > On Thu, Jan 17, 2008 at 10:42:09PM +0100, Ingo Molnar wrote: > > > > > > * Siddha, Suresh B <[EMAIL PROTECTED]> wrote: > > > > > > > On Thu, Jan 17, 2008 at 10:13:08PM +0100, Ingo Molnar wrote: > > > > > but in general we must be robust enough in this case and just degrade > > > > > any overlapping page to UC (and emit a warning perhaps) - instead of > > > > > failing the ioremap and thus failing the driver (and the bootup). > > > > > > > > But then, this will cause an attribute conflicit. Old one was > > > > specifying WB in PAT (ioremap with noflags) and the new ioremap > > > > specifies UC. > > > > > > we could fix up all aliases of that page as well and degrade them to UC? > > > > Yes, we must fix all aliases or reject the conflicting mapping. But > > fixing all aliases might not be that easy. (I've just seen a panic > > when using your patch ;-( > > yes, indeed my patch is bad if you have PAT enabled: conflicting cache > attributes might be present. I'll go with your patch for now.
I think the best is to just reject conflicting mappings. (Because now I am too tired to think about a safe way how to change the aliases to the most restrictive memory type. ;-) But then of course such boot-time problems like I've seen on my test machines should be avoided somehow. Andreas -- 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/
