On Fri, May 22, 2015 at 10:25:10AM +0000, Joao Martins wrote: > > On 19 May 2015, at 17:32, Wei Liu <wei.l...@citrix.com> wrote: > > > On Tue, May 12, 2015 at 07:18:28PM +0200, Joao Martins wrote: > >> It starts by doing a lookup in the tree for a gref. If no persistent > >> grant is found on the tree, it will do grant copy and prepare > >> the grant maps. Finally valides the grant map and adds it to the tree. > > > > validates? > > > >> After mapped these grants can be pulled from the tree in the subsequent > >> requests. If it's out of pages in the tree pool, it will fallback to > >> grant copy. > >> > > > > Again, this looks complicated. Why use combined scheme? I will do > > detailed reviews after we're sure we need such scheme. > When we don't have the gref in tree we need to map it and then copying > afterwards into the newly mapped page (and this only happens once until > the grant is in tree). My options here were to either do this explicitly, > after we add the persistent grant in which we would need to save to > dst/src address and len to copy. The other option is to reuse the grant > copy (since it's only once until the grant is in the tree) and use memcpy > in followings requests. Additionally I allow the fallback to grant copy in
Which approach were you using here? I looked at the code but couldn't quite get which one you were getting at. I guess the first one? > case the guest provides providing more grefs > max_grants. > > Note that this is also the case for TX as well, with regard to grant > copying the header. I was unsure about which one is the most correct way > of doing it, but ultimately the latter involved a smaller codepath, and > that's why I chose it. What do you think? > Shorter is better. Easier to understand. Wei. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
