Chris Roose wrote: > Jason Unovitch wrote: > > Does anything change if you set -tso -lro on the serving NIC on your > > FreeBSD server side? Do the Linux clients remain responsive then? > > Thank you, Jason. This seems to have cleared the problem up for me. > Since disabling TSO and LRO on the server NIC last night, I haven't seen > any timeouts. I think there might be a couple of reasons that disabling TSO resolves this: 1 - The obvious one is that the net chip/driver is broken for certain TSO segments. Often the culprit is a NFS read reply of just less than 64K, that is made up of a chain of 33mbufs with a total length just under 64K. Then the driver adds a MAC layer header that bumps the size up to greater than 64K. --> This can happen if the driver does not set the TSO sizing parameters quite correctly, among other things.
2 - TSO does work correctly, but results in different timing of the TCP segments transmitted for the segment compared with non-TSO. I believe that, for otis@, disabling TSO reduced the frequency of Linux client hangs, but did not stop them. --> reverting the patch in r367492 (this patch is not in FreeBSD12) has fixed the problem for him. rick -- Chris _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org" _______________________________________________ freebsd-current@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"