> > > > You already must not place any data structures into WC memory --- for > > > > example, spinlocks wouldn't work there. > > > > > > What do you mean "already"? > > > > I mean "in current kernel" (I checked it in 2.6.22) > > Ahh, that's not "current kernel", though ;) > > 4071c718555d955a35e9651f77086096ad87d498 > > > So drivers can't assume that wmb() works on write-combining memory. > > Drivers should be able to assume that wmb() orders _everything_ (except > some whacky Altix thing, which I really want to fold under wmb at some > point anyway). > > So I decided that old x86 semantics isn't right, and now it really is a > lock op / sfence everywhere.
I see. I'm just curious --- is there any real usage for WC memory, except graphics card memory? Mikulas - 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/