From owner-freebsd-hackers@freebsd.org Thu Aug 23 09:02:25 2018 Return-Path: Delivered-To: freebsd-hackers@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3DA541086BDF for ; Thu, 23 Aug 2018 09:02:25 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from hz.grosbein.net (hz.grosbein.net [IPv6:2a01:4f8:d12:604::2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "hz.grosbein.net", Issuer "hz.grosbein.net" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id BA81988FC3 for ; Thu, 23 Aug 2018 09:02:24 +0000 (UTC) (envelope-from eugen@grosbein.net) Received: from eg.sd.rdtc.ru (eg.sd.rdtc.ru [IPv6:2a03:3100:c:13:0:0:0:5]) by hz.grosbein.net (8.15.2/8.15.2) with ESMTPS id w7N920GX086159 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Thu, 23 Aug 2018 11:02:01 +0200 (CEST) (envelope-from eugen@grosbein.net) X-Envelope-From: eugen@grosbein.net X-Envelope-To: sebastian.huber@embedded-brains.de Received: from eg.sd.rdtc.ru (eugen@localhost [127.0.0.1]) by eg.sd.rdtc.ru (8.15.2/8.15.2) with ESMTP id w7N91uGg017091; Thu, 23 Aug 2018 16:01:56 +0700 (+07) (envelope-from eugen@grosbein.net) Subject: Re: epoch(9) background information? To: Sebastian Huber , FreeBSD References: <3bfedcc3-0dae-7979-2bd4-da83f2c67e87@embedded-brains.de> From: Eugene Grosbein Message-ID: <5B7E7804.4030907@grosbein.net> Date: Thu, 23 Aug 2018 16:01:56 +0700 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <3bfedcc3-0dae-7979-2bd4-da83f2c67e87@embedded-brains.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=0.3 required=5.0 tests=BAYES_00, DATE_IN_FUTURE_96_Q, LOCAL_FROM, SPF_PASS autolearn=no autolearn_force=no version=3.4.1 X-Spam-Report: * -0.0 SPF_PASS SPF: sender matches SPF record * 0.0 DATE_IN_FUTURE_96_Q Date: is 4 days to 4 months after Received: date * -2.3 BAYES_00 BODY: Bayes spam probability is 0 to 1% * [score: 0.0000] * 2.6 LOCAL_FROM From my domains X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on hz.grosbein.net X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 23 Aug 2018 09:02:25 -0000 On 23.08.2018 15:39, Sebastian Huber wrote: > We used the FreeBSD network stack also on low-end targets > (uni-processor) such as MCF548x ColdFire, Atmel SAM V71, SPARC LEON, > etc. in current production environments (not legacy systems). The > introduction of lock-free data structures (Concurrency Kit) and this > epoch memory reclamation makes little sense on these targets (at least > from my point of view). However, FreeBSD has still the SMP configuration > option (sys/conf/options) which suggests that SMP is optional. Is a > uni-processor system something which is considered by the FreeBSD > community as a thing worth supporting or can I expect that this is an > exotic environment which will get less and less well supported in the > future? I just need some guidance so that I can better plan for future > FreeBSD baseline updates. FreeBSD as virtualized uniprocessor guest should be supported at full scale, as well as embedded applications using single core x86 and non-x86 CPUs. Just my 2 cents.