Date: Wed, 24 Feb 2021 21:40:31 +0000 From: Alexander V. Chernikov <melifaro@ipfw.ru> To: =?utf-8?B?T2xpdmllciBDb2NoYXJkLUxhYmLDqQ==?= <olivier@freebsd.org>, Marek Zarychta <zarychtam@plan-b.pwste.edu.pl> Cc: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Re: option FIB_ALGO and dpdk_lpm4 Message-ID: <2892341614202492@mail.yandex.ru> In-Reply-To: <CA%2Bq%2BTcqTh55fZbYQTt7giN-c9kL8iF28QDoaaF1vKXhyW6RsNA@mail.gmail.com> References: <5670cd9a-cd10-2b89-1347-97a6c817c50f@sentex.net> <8696072a-dc25-8eff-04fa-4d1db13bf5cc@plan-b.pwste.edu.pl> <3588111612809020@mail.yandex.ru> <53ef5715-42ce-aad0-9a8b-11d91a9891e3@plan-b.pwste.edu.pl> <301391612827263@mail.yandex.ru> <ecb75bc5-72fe-4583-8fe6-e0cb5347ae02@plan-b.pwste.edu.pl> <2642181612914660@mail.yandex.ru> <2951613086198@mail.yandex.ru> <b51320bb-d401-3d96-64a6-139f2c980ffa@plan-b.pwste.edu.pl> <7121614026888@mail.yandex.ru> <7056db64-2e7f-6ad8-54a3-59ff406061cf@plan-b.pwste.edu.pl> <CA%2Bq%2BTcqTh55fZbYQTt7giN-c9kL8iF28QDoaaF1vKXhyW6RsNA@mail.gmail.com>
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24.02.2021, 10:50, "Olivier Cochard-Labbé" <olivier@freebsd.org>: > On Wed, Feb 24, 2021 at 1:22 AM Marek Zarychta < > zarychtam@plan-b.pwste.edu.pl> wrote: > >> > >> >> Please let me ask only one final question. Does adding: >> >> net.route.algo.inet.algo=dpdk_lpm4 >> net.route.algo.inet6.algo=dpdk_lpm6 >> >> to /etc/sysctl.conf make any sense? I see that right FIB_ALGO is >> automatically picked up when the module is available. > > My understanding is the network stack will switch to the optimum algorithm > regarding the number of routes installed. > cf "Automatic algorithm selection" chapter here: > https://reviews.freebsd.org/D27401 > > So you don't need to set this sysctl. To add some points to Olivier's explanation: indeed, algorithm selection SHOULD happen automatically. Some things to keep in mind: when the BGP sessions flaps kernel routes may go from the full-view to near-zero and vice versa. In that case, automatic selection will switch to lockless_radix for the range between 10..1000 routes (or similar). Lockless radix schedules rebuild for every change, so the speed of deleting/adding first 1k routes may be slower than expected. > > Regards, > > Olivier > _______________________________________________ > freebsd-net@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-net > To unsubscribe, send any mail to "freebsd-net-unsubscribe@freebsd.org"
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