From owner-freebsd-arm@freebsd.org Wed Jul 18 19:35:48 2018 Return-Path: Delivered-To: freebsd-arm@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 96DF6102F947 for ; Wed, 18 Jul 2018 19:35:48 +0000 (UTC) (envelope-from marklmi@yahoo.com) Received: from sonic311-22.consmr.mail.gq1.yahoo.com (sonic311-22.consmr.mail.gq1.yahoo.com [98.137.65.203]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 1B9AF89A61 for ; Wed, 18 Jul 2018 19:35:47 +0000 (UTC) (envelope-from marklmi@yahoo.com) X-YMail-OSG: _OuJr78VM1lIAC0lbVcJgiDHxYz2EnXd.5AdYEhaBRUpWvVq2IinrFR0pwMregy M4Dbhe1_iZAMeYECyn1hey.4AAHBxfhQC23wwHMfY2iM7it_Su6hZPW.WzvRbsq5XCslyw65cpvg dzson.17BGpOxAdeXdP0UpGRnsSZvSICAvES4VBP0DWa61_cL6QUzvhFX9iNqpQ3uAO8YR6hy58Z I9wnAo_oPBJksxJ6sNxAAPgt_tw9qsUbFVm0NbIpN7Uh.wNWDBdZgsUNaMcFDJ_Y01PLHwd8OqKL kaio3Xu50y.IF6YpDdYwk_owT4XnkI1grsTpDQopZqEE7PiAQy4DRUEs2uRYI5DVH6KaPkAvk5my o3rbyWZ9w2nV1cKQYiYTTkOjlb5qmZaElIdHubLifwmrSB7D8a2tTQxPcvQdMURhspNgwOvaXPyF WhXQW6wEL8O25241uqJcKeCYzVpCkHsjBNRizd8hgUnagMFeS_hHWcX9HUNHKozBic_D.wnJJcTa YWtDAMm5LmDtbzEP4Ybn3_8sC1sb7nfXQ3JfzrLYwO1hLeXWid3ZebjDP_mrh386L06ckrNki1D1 HKC0UUR5jSvy_InLEDUhvatfXoBIyhADDmDTYqA.FzRJwOTdVhAwInB9V3ieOPJuAS.hOlILL7yM s5__6tUXn.p1gVyzfSN3L21cPPa4DdJ5gLuIMj0zelCXFUXhqYa2RXIpo7Nt8rYwsQGa87161MuL rSG3NurZkX_ypjX_WN4IjVsLsp3hyw.J3lJDcJrtBOrcV_D.jzMCnpfCexAzqczw_veUUwO1naL3 iLzrc_i1RAZ72w7ZJo3_kQGTwYGlCwCnCgOdYpdbsoiFSWhyCXTwMKpSPRsOpsm.vLWKIXjrgyvG zffHzVRds_mZlWP8D0PySOBT4vYEHvSR_WPvh2KS5pGbztbaBT8Oj6IDpxCVYUg0WUjciJQncEBj q2N3yvQGKUBysG23ubnHQtY_TPWjBQO82usMWgOBxhxcolSeVNG6V2qMN7RVCpCO70FT4 Received: from sonic.gate.mail.ne1.yahoo.com by sonic311.consmr.mail.gq1.yahoo.com with HTTP; Wed, 18 Jul 2018 19:35:41 +0000 Received: from ip70-189-131-151.lv.lv.cox.net (EHLO [192.168.0.105]) ([70.189.131.151]) by smtp425.mail.gq1.yahoo.com (Oath Hermes SMTP Server) with ESMTPA ID 79e50f06e5dc6fa847059acfbae7667e; Wed, 18 Jul 2018 19:35:40 +0000 (UTC) Content-Type: text/plain; charset=us-ascii Mime-Version: 1.0 (Mac OS X Mail 11.5 \(3445.9.1\)) Subject: Re: RPI3 swap experiments From: Mark Millard In-Reply-To: <20180718190951.GB27481@www.zefox.net> Date: Wed, 18 Jul 2018 12:35:38 -0700 Cc: freebsd-arm , Trev Content-Transfer-Encoding: quoted-printable Message-Id: <2CFAE691-3176-4E8C-8542-6D66BE4421A6@yahoo.com> References: <20180629233937.GC35717@www.zefox.net> <0f137e06-214a-3e8c-a216-f061ec04ac2c@sentry.org> <20180630005145.GA43801@www.zefox.net> <6f3406e2-71f3-d0c2-2b65-703e1a1d3c25@sentry.org> <8e92b2b7-da61-3efb-7231-9fac76b2c1d4@sentry.org> <2deaaec3-f78f-0b09-5ca7-27e14c6979f9@sentry.org> <20180704004554.GA61273@www.zefox.net> <20180718060650.GA24566@www.zefox.net> <20180718190951.GB27481@www.zefox.net> To: bob prohaska X-Mailer: Apple Mail (2.3445.9.1) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 18 Jul 2018 19:35:48 -0000 On 2018-Jul-18, at 12:09 PM, bob prohaska wrote: > On Wed, Jul 18, 2018 at 07:42:13AM -0700, Mark Millard wrote: >>=20 >>=20 >> On 2018-Jul-17, at 11:06 PM, bob prohaska = wrote: >>=20 >>> It appears that some progress has been made in getting swap working = reasonably >>> on the RPI3. A -j4 buildworld attempt running r336356 to compile = 336431 failed >>> with "out of swap" but the worst read and write delays were less = than 5 seconds, >>> a marked improvement over previous examples. >>=20 >> Attributing the time variations that have been observed mostly to = FreeBSD and not >> mostly to the device at issue seems to have little or no evidence to = support it. >>=20 > Possibly a fair objection. This test is with a USB3.0 flash drive. = I'll repeat soon > as possible with a USB3.1 device, which in the past reported much = greater (15 second) > delays. >=20 >>> In this case swap was split, 2 each 1GB partitions on USB flash = plus 1 GB on the=20 >>> microSD card. Previous attempts using 3 each 1 GB partitions on USB = flash have been >>> repeatedly successful, while a single attempt using 3 each 1GB = partitions on microSD >>> failed. >>=20 >> The more swap partitions (or space?) not on a /dev/mmcsd0s* the less = of the >> activity that /dev/mmcsd0 handles and likely the more time it tends = to have >> between explicit operations to do internal housekeeping before the = next >> explicit operation. >>=20 >> So the better approximation to not using /dev/mmcsd0 at all might not = be >> all that much of a surprise at having less of a problem on the device >> (or a problem less often). >>=20 > In earlier tests (same card type) putting _all_ swap on microSD (along = with /tmp)=20 > avoided OOMA kills. Dependable mischief seems to come when swap is on = both microSD=20 > and USB. As I do not know what all is going on for Out Of Memory kills, I was = only directly talking of the likes of ms/w and/or ms/r time figures being = large sometimes. OOMA may have other issues contributing to some of its = activity for all I know. Is a difference, for example, 2 GB total swap vs. 3 GB total swap and = the message about the swap configuration? The memory tracking swap can = fragment and be a source of not being able to use swap as I understand. (I've = quoted the man page material in the past in these exchanges.) Large swap spaces can hit such fragmentation issues sooner. (So there is a tradeoff in having more swap than needed as the amount-more increases.) Trev has reported: "I have run the -j4 buildworld now 11 times using a = single 2G partition". I wonder what would happen for him if he used two 1 GB partitions or three about 2/3 GB byte partitions. The contrasting case = of a working environment changed to have multiple partitions (with the same = total) could indicate something about if multiple partitions are sufficient to = lead to problems (ms/w, ms/r, OOM killing, or some combination). > It's understood that USB and Ethernet share I/O hardware, but I = thought microSD=20 > was at least somewhat independent. Is this wrong? >=20 This I do not know. =3D=3D=3D Mark Millard marklmi at yahoo.com ( dsl-only.net went away in early 2018-Mar)