Hi, AFAIK, there is no proper KPI for managing mbuf queue. All users have to re-implements the queue logic from scratch, which is less than optimal. From a preeminent FreeBSD developer at BSDCan 2009: "we do not need a new list implementation". There has been a few attempt of providing a queue API, namely <dev/cxgb/sys/mbufq.h>, but that is nothing more than an ad-hoc solution to something which _has_to_be_ generic. For the sake of adding more mess in the tree, this implementation has been duplicated in <dev/xen/netfront/mbufq.h>...
Now, I understand, or at least merely witness without power, the reluctance of kernel hackers to have 'struct mbuf` evolves, especially wrt. their desire to keep binary compatibility of KPI[0]. Now, none of the current ad-hoc API matched my needs, and I really did NOT want to re-implement a new list implementation for missing basic operation, such as deleting an element of the list, so I came with the attached patch. The main idea is to be able to use already existing code from <sys/queue.h> for mbuf queuing management. It is not the best which can be done. I am not a huge fan of keeping `m_nextpkt' and introducing a `m_nextelm', I would have preferred to use TAILQs, and I do not like the dwelling in SLIST internal implementation details. However, this change is relatively lightweight, and change neither ABI or API. Any comment appreciated. - Arnaud [0]: taking care of having a stable kernel ABI and *not* a stable userland ABI is beyond my understanding, but this is not the subject of this mail.
mbuf_slist.diff
Description: Binary data
_______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[email protected]"
