On 19.02.2018 20:05, Neal Cardwell wrote:
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.
Here they are:
http://vps3.avodz.org/tmp/frto-4.14.11-linux.pcap.xz - 3.3 MB/s
http://vps3.avodz.org/tmp/frto-4.14.11-windows.pcap.xz - connection
completely froze and eventually timed out
http://vps3.avodz.org/tmp/frto-4.14.20+revert-windows.pcap.xz - 5+
MB/s, which almost saturated the link
