On 01/17/17 02:06, Konstantin Belousov wrote: > On Tue, Jan 17, 2017 at 04:57:23AM +0000, Colin Percival wrote: >> I think I've tracked an NFS problem down to sosend returning ERESTART; it >> looks like it's easy to work around this, but I'm not sure *why* sosend is >> returning ERESTART... or for that matter *how* since I can't find anywhere >> in relevant code where that gets returned. > ERESTART is most likely returned by msleep(9) or similar call down the > path when unblocked signal is pending with the restart disposition.
Thanks, looks like that was exactly it -- if the TCP send buffer was full we would call sbwait, and if a signal arrived it would return ERESTART. It looks like setting the SB_NOINTR flag will prevent this; I'm testing a patch right now. (Google bait in case anyone else trips over this: FreeBSD 11.0 NFS client dropping TCP connections under concurrent I/O load.) -- Colin Percival Security Officer Emeritus, FreeBSD | The power to serve Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid _______________________________________________ freebsd-net@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "freebsd-net-unsubscr...@freebsd.org"
