On 28 Jun 2019, at 13:48, Jakub Kicinski wrote: > On Thu, 27 Jun 2019 19:36:42 -0700, Jonathan Lemon wrote: >> On 27 Jun 2019, at 15:42, Jakub Kicinski wrote: >>> Could you be more explicit on the motivation? I'd call this patch set >>> "make all drivers use reuse queue" rather than "clean up". >> >> The motivation is to have packets which were received on a zero-copy >> AF_XDP socket, and which returned a TX verdict from the bpf program, >> queued directly on the TX ring (if they're in the same napi context). >> >> When these TX packets are completed, they are placed back onto the >> reuse queue, as there isn't really any other place to handle them. >> >> It also addresses Maxim's concern about having buffers end up sitting >> on the rq after a ring resize. >> >> I was going to send the TX change out as part of this patch, but >> figured it would be better split unto its own series. > > Makes sense, please put that info in the cover letter. (in other nit > picks please prefix the patches which the name of the subsystem they > are touching - net: xsk: ?, and make sure all changes have a commit > message). > > Looking at this yesterday I think I've seen you didn't change the RQ > sizing - for the TX side to work the rq size must be RX ring size > + XDP TX ring size (IIRC that was the worst case number of packets > which we may need to park during reconfiguration). > > Maybe you did do that and I missed it.
Not yet - that's in the TX section of the patches, I'll post the Intel versions shortly. >>> Also when you're changing code please make sure you CC the author. >> >> Who did I miss? > > commit f5bd91388e26557f64ca999e0006038c7a919308 > Author: Jakub Kicinski <jakub.kicin...@netronome.com> > Date: Fri Sep 7 10:18:46 2018 +0200 > > net: xsk: add a simple buffer reuse queue > > XSK UMEM is strongly single producer single consumer so reuse of > frames is challenging. Add a simple "stash" of FILL packets to > reuse for drivers to optionally make use of. This is useful > when driver has to free (ndo_stop) or resize a ring with an active > AF_XDP ZC socket. > > Signed-off-by: Jakub Kicinski <jakub.kicin...@netronome.com> > Tested-by: Andrew Bowers <andrewx.bow...@intel.com> > Signed-off-by: Jeff Kirsher <jeffrey.t.kirs...@intel.com> > > > Sorry to get upset, I missed a bpf patch recently and had to do > a revert.. Ack.
