On Tue, Apr 12, 2016 at 2:40 PM, Ben Greear <gree...@candelatech.com> wrote: > On 04/12/2016 01:29 PM, Eric Dumazet wrote: >> >> On Tue, 2016-04-12 at 13:23 -0700, Ben Greear wrote: >> >>> It worked well enough for years that I didn't even know other algorithms >>> were >>> available. It was broken around 4.0 time, and I reported it to the list, >>> and no one seemed to really care enough to do anything about it. I >>> changed >>> to reno and ignored the problem as well. >>> >>> It is trivially easy to see the regression when using ath10k NIC, and >>> from this email >>> thread, I guess other NICs have similar issues. >> >> >> Since it is so trivial, why don't you start a bisection ? > > > I vaguely remember doing a bisect, but I can't find any email about > that, so maybe I didn't. At any rate, it is somewhere between 3.17 and 4.0. > From memory, it was between 3.19 and 4.0, but I am not certain of that. > > Neil's suggestion, from the thread below, is that it was likely: "605ad7f > tcp: refine TSO autosizing" > > Here is previous email thread: > > https://www.mail-archive.com/netdev@vger.kernel.org/msg80803.html > > This one has a link to a pcap I made at the time: > > https://www.mail-archive.com/netdev@vger.kernel.org/msg80890.html based on the prev thread I propose we disable hystart ack-train. It is brittle under various circumstances. We've disabled that at Google for years.
> >> >> I asked a capture, I did not say ' switch to Reno or whatever ', right ? >> >> Guessing is nice, but investigating and fixing is better. >> >> Do not assume that nothing can be done, please ? > > > Thanks, > Ben > > -- > Ben Greear <gree...@candelatech.com> > Candela Technologies Inc http://www.candelatech.com >
