actually... all of my devices, including my desktop connect through wifi these days... and only one of them isn't running some variant of linux. On Thu, Jun 21, 2018 at 10:18 AM Dave Taht wrote: > On Thu, Jun 21, 2018 at 5:55 AM, Eric Dumazet > wrote: > > > > > > On 06/21/2018 02:22 AM, Toke Høiland-Jørgensen wrote: > >> Dave Taht writes: > >> > >>> Nice war story. I'm glad this last problem with the fq_codel wifi code > >>> is solved > >> > >> This wasn't specific to the fq_codel wifi code, but hit all WiFi devices > >> that were running TCP on the local stack. Which would be mostly laptops, > >> I guess... > > > > Yes. > > > > Also switching TCP stack to always GSO has been a major gain for wifi in > my tests. > > > > (TSQ budget is based on sk_wmem_alloc, tracking truesize of skbs, and > not having > > GSO is considerably inflating the truesize/payload ratio) > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0a6b2a1dc2a2105f178255fe495eb914b09cb37a > > tcp: switch to GSO being always on > > > > I expect SACK compression to also give a nice boost to wifi. > > > > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5d9f4262b7ea41ca9981cc790e37cca6e37c789e > > tcp: add SACK compression > > > > Lastly I am working on adding ACK compression in TCP stack itself. > > One thing I've seen repeatedly on mac80211 aircaps is a tendency for > clients to use up two TXOPs rather than one. > > scenario: > > 1) A tcp burst arrives at the client > 2) A single ack migrates down the client stack into the driver, into > the device, which then attempts to compete for airtime on that TXOP > for that single ack, sometimes waiting 10s of msec to get that op > 3) a bunch more acks arrive "slightly late"[1], and then get queued > for the next TXOP, waiting, again sometimes 10s of msec > > (similar scenario in a client making a quick string of web related > requests) > > This is a case where inserting a teeny bit more latency to fill up the > queue (ugh!), or a driver having some way to ask the probability of > seeing more data in the > next 10us, or... something like that, could help. > > ... > > [1] if you need coffee through your nose this morning, regarding usage > of the phrase "slightly late", read > http://www.rawbw.com/~svw/superman.html > > -- > > Dave Täht > CEO, TekLibre, LLC > http://www.teklibre.com > Tel: 1-669-226-2619 <(669)%20226-2619> > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > -- Caleb Cushing http://xenoterracide.com