On Thu, Jan 23, 2020 at 8:25 PM Gleb Smirnoff <gleb...@freebsd.org> wrote: > Because at interrupt level we can batch multiple packets in a single epoch. > This speeds up unfiltered packet forwarding performance by 5%. > > With driver level pfil hooks I would claim even more improvement, because > before > the change we needed to enter epoch twice - once for filtering, than for > ether_input. > > Epoch isn't a layer, it is a synchronisation primitive, so I disagree about > statement on layering violation.
Epoch is a synchronization primitive, but the net_epoch is absolutely a part of the networking layer. If we need better batching then the correct solution is to introduce a batched interface for drivers to push packets up the stack, not to mess around at the interrupt layer. Note that the only reason why this works for mlx4/mlx5 is that linuxkpi *always* requests a INTR_TYPE_NET no matter what driver is running. This means that all drm graphics driver interrupts are now running under the net_epoch: https://svnweb.freebsd.org/base/head/sys/compat/linuxkpi/common/include/linux/interrupt.h?revision=352205&view=markup#l103 _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
