On Mon, Feb 19, 2018 at 11:17 AM, Teodor Milkov <t...@del.bg> wrote: > On 19.02.2018 15:38, Neal Cardwell wrote: >> >> On Sun, Feb 18, 2018 at 4:02 PM, Teodor Milkov <t...@del.bg> wrote: >>> >>> Hello, >>> >>> I've numerous reports from Windows users that after kernel upgrade from >>> 4.9 >>> to 4.14 they experienced major slow downs and transfer stalls. >>> >>> After some digging, I found that the slowness starts with this commit: >>> >>> tcp: extend F-RTO to catch more spurious timeouts (89fe18e44) >>> >>> >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=89fe18e44f7ee5ab1c90d0dff5835acee7751427 >>> >>> Which is partially reverted later with this one: >>> >>> tcp: restrict F-RTO to work-around broken middle-boxes (cc663f4d4) >>> >>> >>> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cc663f4d4c97b7297fb45135ab23cfd508b35a77 >>> >>> But, still, we had stalls until I fully reverted 89fe18e44. >> >> Thanks for the report. Do you have any other details that might help >> evaluate this issue? > > > I'm sorry I didn't provide more info. It was long session. > >> Any packet traces, by any chance? > > > I'll try and obtain one.
Great! Yes, if you could obtain a sender-side tcpdump that captured one of these slow-down/stalls, that would be fantastic. It would be great to be able to understand what's going on. We only need headers, so something like the following would be fine: tcpdump -c2000000 -w /tmp/test.pcap -s 120 -i $ETH_DEVICE port $PORT Then if you could post on a web server or Google drive, etc, that'd be great. Thanks for all the additional details! neal