Date: Tue, 08 Sep 2020 22:50:34 +0100 From: Alexander V. Chernikov <melifaro@freebsd.org> To: Andriy Gapon <avg@freebsd.org>, "src-committers@freebsd.org" <src-committers@freebsd.org>, "svn-src-all@freebsd.org" <svn-src-all@freebsd.org>, "svn-src-head@freebsd.org" <svn-src-head@freebsd.org> Subject: Re: svn commit: r364465 - in head/sys: conf net net/route Message-ID: <93541599601730@mail.yandex.ru> In-Reply-To: <69399f59-4eca-ee29-7230-678a02cf6eff@FreeBSD.org> References: <202008212134.07LLYq3K071532@repo.freebsd.org> <69399f59-4eca-ee29-7230-678a02cf6eff@FreeBSD.org>
next in thread | previous in thread | raw e-mail | index | archive | help
08.09.2020, 21:03, "Andriy Gapon" <avg@freebsd.org>: > 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? Hi Andriy, Does r365475 fix the problem for you? CTLFLAG_RWTUN flag got slipped through the cracks somewhere :-( > 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?93541599601730>