Jesper Dangaard Brouer <brouer@xxxxxxxxxx> writes: > On Tue, 07 Jan 2020 14:27:41 +0100 > Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: > >> Jesper Dangaard Brouer <brouer@xxxxxxxxxx> writes: >> >> > On Tue, 07 Jan 2020 12:25:47 +0100 >> > Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: >> > >> >> Björn Töpel <bjorn.topel@xxxxxxxxx> writes: >> >> >> >> > On Fri, 20 Dec 2019 at 11:30, Toke Høiland-Jørgensen <toke@xxxxxxxxxx> wrote: >> >> >> >> >> >> Jesper Dangaard Brouer <brouer@xxxxxxxxxx> writes: >> >> >> >> >> > [...] >> >> >> > I have now went over the entire patchset, and everything look perfect, >> >> >> > I will go as far as saying it is brilliant. We previously had the >> >> >> > issue, that using different redirect maps in a BPF-prog would cause the >> >> >> > bulking effect to be reduced, as map_to_flush cause previous map to get >> >> >> > flushed. This is now solved :-) >> >> >> >> >> >> Another thing that occurred to me while thinking about this: Now that we >> >> >> have a single flush list, is there any reason we couldn't move the >> >> >> devmap xdp_bulk_queue into struct net_device? That way it could also be >> >> >> used for the non-map variant of bpf_redirect()? >> >> >> >> >> > >> >> > Indeed! (At least I don't see any blockers...) >> >> >> >> Cool, that's what I thought. Maybe I'll give that a shot, then, unless >> >> you beat me to it ;) >> > >> > Generally sounds like a good idea. >> > >> > It this only for devmap xdp_bulk_queue? >> >> Non-map redirect only supports redirecting across interfaces (the >> parameter is an ifindex), so yeah, this would be just for that. > > Sure, then you don't need to worry about below gotchas. > > I do like the idea, as this would/should solve the non-map redirect > performance issue. Yes, that was exactly my thought. Taking a stab at it now... :) >> > Some gotchas off the top of my head. >> > >> > The cpumap also have a struct xdp_bulk_queue, which have a different >> > layout. (sidenote: due to BTF we likely want rename that). >> > >> > If you want to generalize this across all redirect maps type. You >> > should know, that it was on purpose that I designed the bulking to be >> > map specific, because that allowed each map to control its own optimal >> > bulking. E.g. devmap does 16 frames bulking, cpumap does 8 frames (as >> > it matches sending 1 cacheline into underlying ptr_ring), xskmap does >> > 64 AFAIK (which could hurt-latency, but that is another discussion). >> >> Björn's patches do leave the per-type behaviour, they just get rid of >> the per-map flush queues... :) > > Yes, I know ;-) I know you do; was just a bit puzzled why you brought up all that other stuff, and, well, had to answer something, didn't I? ;) -Toke
