On Saturday 13 February 2010 17:04:58 Max Laier wrote: > Author: mlaier > Date: Sat Feb 13 16:04:58 2010 > New Revision: 203834 > URL: http://svn.freebsd.org/changeset/base/203834 > > Log: > Fix drbr and altq interaction: > - introduce drbr_needs_enqueue that returns whether the interface/br > needs an enqueue operation: returns true if altq is enabled or there are > already packets in the ring (as we need to maintain packet order) - update > all drbr consumers > - fix drbr_flush > - avoid using the driver queue (IFQ_DRV_*) in the altq case as the > multiqueue consumer does not provide enough protection, serialize altq > interaction with the main queue lock > - make drbr_dequeue_cond work with altq > > Discussed with: kmacy, yongari, jfv > MFC after: 4 weeks > > Modified: > head/sys/dev/cxgb/cxgb_sge.c > head/sys/dev/e1000/if_em.c > head/sys/dev/e1000/if_igb.c > head/sys/dev/ixgbe/ixgbe.c > head/sys/dev/mxge/if_mxge.c > head/sys/net/if_var.h
Note that em, igb and ixgbe are still subtly broken after this. The problem is that they all call drbr_enqueue after failure to transmit a previously dequeued packet. This might mess up the packet order as the buf_rings are strictly FIFO. The fix is to make sure that there are enough resources to transmit before dequeuing the packet (drbr_dequeue_cond may be helpful here) and discarding the packet if the transmission fails for any other reason. Regards, Max _______________________________________________ svn-src-head@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
