On 01.11.2017 22:35, Lev Serebryakov wrote: > > Now 11-STABLE (and 12-CURRENT too) have this: > > sys/netinet/udp_usrreq.c:#define UDBHASHSIZE 128 > > Looks like such low value could lead to 100% consumption of CPU by > interrupt threads (igb queues in my case) on heavy incoming UDP traffic > (torrents with uTP in my case). > > My system (E3-1220v3 with I210 NICs) becomes completely unresponsive > (nut complains about lost connection to UPS, ssh to system times out, > etc) when system downloads torrent with many uTP (UDP) peers. Four igb0 > queues consume 100% CPU each in this scenario. > > Total traffic could be very low like 500KiB/s (yes, 500KiB/s, not > MiB/s!), I don't speak about 1Gbit/s or even 100Mbit/s here! > > Rebuilding kernel with UDBHASHSIZE=16384 seems to help. > > Why is this value so low and why I need to patch sources to change it? > Many such settings are changeable via sysctl and/or tunables, but this > one looks hardcoded.
You should fill a PR. Attach these performance numbers you got. If possible, attach a patch introducing new loader tunnable, that should be easy. Keep me CC'd. _______________________________________________ freebsd-stable@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
