On Sun, Jan 28, 2018 at 5:18 PM, Sowmini Varadhan <sowmini.varad...@oracle.com> wrote: > On (01/28/18 14:51), Willem de Bruijn wrote: >> > On (01/25/18 15:44), Willem de Bruijn wrote: > ; >> >> You may alos be able to do the same as tcp zerocopy and >> >> hold an sk reference on the notification skb. > ; >> I don't quite follow. Every notification skb is created when pages refcount >> is increased. It persists until at least rds_rm_zerocopy_callback, after data >> skb has been freed and pages refcount has been decreased. >> >> In this callback, skb is consumed if another skb is already queued on >> the error queue, otherwise it is queued itself. It needs to hold a sock ref >> until it can be queued. > > maybe I did not follow the original suggestion- were you > suggesting that I hold a pointer to the sk from e.g., the skb->cb > itself?
Yes, I mean associating the notification skb that is eventually queued onto the error queue with the socket. For tcp zerocopy, this happens implicitly in sock_omalloc. > I dont know that it would make things simpler, > whereas having the pointer and refcount in the rds_message itself, > and track this independantly of whether/not zcopy was used, seems > like a more consistent dsta-structure model, so I'd like to leave > this as is. Sounds good. You know the rds internals a lot better than I do, so are the better judge on whether to choose that or sock_omalloc.
