> To elaborate on this one... I realise for this one that in the kernel > where this is currently used everything is non-preemptible anyway > because of the ptl. And I also realise that -rt kernel issues don't > really have a bearing on mainline kernel.. but the generic > implementation of this API is fundamentally used to operate on a > per-cpu data structure that is only required when tearing down page > tables. That makes this necessarily non-preemptible. > > Which shows that it adds more restrictions that may not otherwise be > required.
Yes, it's a bit annoying but not necessarily that bad. In fact, we don't have to make it non-preemptible, we did it because it was easier that way I strongly suspect. In fact, the batch could actually be attached to the mm rather than the CPU for that matter, no ? Or is there a fudamental reason I'm not seeing why it -has- to be per-cpu ? > > has to look in there and touch the cacheline. You're also having to > > do more work when unlocking/relocking the ptl etc. > > > > > >> I really think it's the right API > > OK, the *form* of the API is fine, I have no arguments. I just don't > know why you have to reuse the same thing. If you provided a new set of > names then you can trivially do a generic implementation which compiles > to exactly the same code for all architectures right now. That seems to > me like the right way to go... But that means two different APIs for almost the same thing. I'm trying to clean up the mess, not add more :-) Beside, that "other" API would have overall much of the same issues no ? Or do you want to have that "other" API not actually provide a percpu "mmu_gather" type structure at all in asm-generic (but basically just boil down to an empty inline for creating the "other" batch and flush_tlb_mm() for finishing it with an empty inline for "adding" a PTE to the list of invalidation targets ?) Ben. - 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/
