On 21 November 2014 07:32, Robert N. M. Watson <rwat...@freebsd.org> wrote: > > On 21 Nov 2014, at 15:20, Marko Zec <z...@fer.hr> wrote: > >>> Bjoern and I chatted for the last twenty or so minutes about the >>> code, and believe that as things stand, it is *not* safe to turn off >>> UMA_ZONE_NOFREE for TCP due to a teardown race in TCP that has been >>> known about and discussed for several years, but is some work to >>> resolve and that we've not yet found time to do so. The XXXRW's in >>> tcp_timer.c are related to this. We're pondering ways to fix it but >>> think this is not something that can be rushed. >> >> OK fair enough - thanks a lot for looking into this! >> >> Skimming through a bunch of hosts with moderately loaded hosts with >> reasonably high uptime I couldn't find one where net.inet.tcp.timer_race >> was not zero. A ny suggestions how to best reproduce the race(s) in >> tcp_timer.c? > > They would likely occur only on very highly loaded hosts, as they require > race conditions to arise between TCP timers and TCP close. I think I did > manage to reproduce it at one stage, and left the counter in to see if we > could spot it in production, and I have had (multiple) reports of it in > deployed systems. I'm not sure it's worth trying to reproduce them, given > that knowledge -- we should simply fix them. >
Wasn't this just fixed by Julien @ Verisign? As for the vimage stability side of things - I'd really like to see some VIMAGE torture tests written. Stuff like "do a high rate TCP connection test whilst creating and destroying VIMAGEs." -adrian _______________________________________________ freebsd-net@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
