On 22/08/2020 00:34, Alexander V. Chernikov wrote: > Author: melifaro > Date: Fri Aug 21 21:34:52 2020 > New Revision: 364465 > URL: https://svnweb.freebsd.org/changeset/base/364465 > > Log: > Make net.fibs growable. > > Allow to dynamically grow the amount of fibs in each vnet. > > This change alters current behavior. Currently, if one defines > ROUTETABLES > 1 in the kernel config, each vnet will be created > with the number of fibs defined in the kernel config. > After this commit vnets will be created with fibs=1. > > Dynamic net.fibs is not compatible with net.add_addr_allfibs. > The plan is to deprecate the latter and make > net.add_addr_allfibs=0 default behaviour. > > Reviewed by: glebius > Relnotes: yes > Differential Revision: https://reviews.freebsd.org/D26062
I wonder why no one reported a problem that I am seeing after upgrading past this revision. Maybe because I do have net.fibs=2 in my loader.conf? The problem -- unfortunately I only have a screenshot -- but it's a page fault trap in this call chain: sysctl_register_all -> sysctl_load_tunable_by_oid_locked -> sysctl_fibs -> _sx_xlock. The crash is on the RTABLES_LOCK() line. And it's kind of obvious why. The tunables, including net.fibs which is declared as RWTUN, are set at SI_SUB_TUNABLES stage, but RTABLES_LOCK_INIT() is not called until SI_SUB_PROTO_DOMAIN much later. In other words, sysctal_fibs can be called earlier than vnet_rtables_init. I think that the best way to handle the problem would be to add CTLFLAG_NOFETCH to the sysctl declaration and then to add -- if necessary at all -- an explicit query of the kenv. -- Andriy Gapon _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
