On 19 October 2017 at 18:04, Andrew Baumann <[email protected]> wrote: >> From: Peter Maydell [mailto:[email protected]] >> Sent: Thursday, 19 October 2017 09:51 >> >> On 18 October 2017 at 01:16, Andrew Baumann >> <[email protected]> wrote: >> Hi; thanks for this patch. Looks like you forgot to add your >> signed-off-by line. > > Thanks for the review! > > I didn’t sign the patch, because it wasn't ready to go in, and my (limited) > understanding of the protocol is that that's one of the things you're > certifying in a signature.
Usually the way we do it is that if you have something that isn't ready to go in, you mark it as [RFC], but you leave your signed-off-by tag on it. That way if you should (hypothetically) disappear without having time to update the RFC to a working version, somebody else can start with the code you posted to the list and work on it. Signed-off-by is really saying "I did this work and it's ok for this to be distributed under the project's license", rather than a claim about the quality of the code. >> So you want the page table walk functions to directly fill in >> the information about cacheability and shareability, including >> doing lookups in MAIR registers (or PRRR/NMRR registers, which >> QEMU stores in the same CPUState fields, but they have a different >> format.) > > I agree. FWIW, the original reason for doing it here was that I > didn't want to slow down the normal page-table walk with additional > logic to compute the attributes, which isn't necessary for a TLB > fill. If we're adding extra out parameters to the walker, then I > can make those optional and skip computing them when the parameter > is NULL. Sure, though I think that if we've got to the point of having to do a page table walk then we're already very much in the slow path, so I don't mind if we just fill out the attributes every time. thanks -- PMM
