From owner-freebsd-current@freebsd.org Thu Jun 8 21:18:41 2017 Return-Path: Delivered-To: freebsd-current@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id E9C10C79CD4 for ; Thu, 8 Jun 2017 21:18:41 +0000 (UTC) (envelope-from etnapierala@gmail.com) Received: from mail-wm0-x235.google.com (mail-wm0-x235.google.com [IPv6:2a00:1450:400c:c09::235]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 695DC71DAC for ; Thu, 8 Jun 2017 21:18:41 +0000 (UTC) (envelope-from etnapierala@gmail.com) Received: by mail-wm0-x235.google.com with SMTP id d64so353883wmf.1 for ; Thu, 08 Jun 2017 14:18:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:subject:message-id:mail-followup-to:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to:user-agent; bh=z0YwTEgHkeOdRQLWjlnRu1JHqxVGBLufucmE3cVEj7Q=; b=WTtUkS9FC5SVY2R6WH3DfrX5WAXfzHygdwIviKOVqaEseU0rj8GSKXUVA37KLxr6zH FZHPbJMoKbwXsyxf4nFQQydnjZbQmG4OSMzeAVBsOuatxjmkzEHM56C77dHWogBhHA5v R0MkjkYO2ATWG+vsyTibGTevPtUm3Pw6wCfipkM0zvOKt7JfMPRzD69tDEeQx3H3imDH SZF/pQxWVqwqI4EJCr8umyeJ3BNr7RW05ib7VPhtPP9IH0uApsKW8+TM/BWQTULWc7QZ 4vi1DA1Q/7fPhCxKd3wuoMHl5zFoO6hA8DOC3aScc1EElsr3MNpeAQ0TFSzeyU503NcD 9JeA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:subject:message-id :mail-followup-to:references:mime-version:content-disposition :content-transfer-encoding:in-reply-to:user-agent; bh=z0YwTEgHkeOdRQLWjlnRu1JHqxVGBLufucmE3cVEj7Q=; b=HkRcl5LYKqohTUCudVhPWKwgD4E7btFZc29DPsrX635EtWmQyXOXsGNtjC/xpstwC3 Btn+l7p6RZhNEslUQKUt1FLfZiPCwh4+I7WrwsL2YxSIQ/OOgIO+uBQIU0JdaV24o0tH egYQN9eRBaXzGqpWa4fhpqkHFvSIJ2NZIQo2kncYdQwA/LQB2jMVjLp3/7yM9mlH66jx 9DTXmcLR7kbllZmsG4x4Vge8i575bF33pfU7JHaIGUCEQzUDTAMGCgCHQckfDRV3tZNS utfFMNCE1LvBhtD5Hl/ns5AaH5G3zp0b8Jaf7konRmpwTMOUpvmVbmb0vc8atsKFkKCW 5pAw== X-Gm-Message-State: AODbwcB1kPKEVpAOo1nbE0XktC0vuAEREcEm/C1W8uwn+UFbGAst+yYM lZJH8NntvCcx0PiF X-Received: by 10.28.216.205 with SMTP id p196mr4882352wmg.18.1496956718295; Thu, 08 Jun 2017 14:18:38 -0700 (PDT) Received: from brick (cpc92310-cmbg19-2-0-cust934.5-4.cable.virginm.net. [82.9.227.167]) by smtp.gmail.com with ESMTPSA id e24sm8779264wre.54.2017.06.08.14.18.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 08 Jun 2017 14:18:37 -0700 (PDT) Sender: =?UTF-8?Q?Edward_Tomasz_Napiera=C5=82a?= Date: Thu, 8 Jun 2017 22:18:35 +0100 From: Edward Tomasz =?utf-8?Q?Napiera=C5=82a?= To: Hans Petter Selasky , Tomoaki AOKI , freebsd-current@freebsd.org Subject: Re: Time to increase MAXPHYS? Message-ID: <20170608211835.GA5348@brick> Mail-Followup-To: Hans Petter Selasky , Tomoaki AOKI , freebsd-current@freebsd.org References: <0100015c6fc1167c-6e139920-60d9-4ce3-9f59-15520276aebb-000000@email.amazonses.com> <972dbd34-b5b3-c363-721e-c6e48806e2cd@elischer.org> <3719c729-9434-3121-cf52-393a4453d0b2@freebsd.org> <20170604163948.eb5f74ce2a233b8f204ba671@dec.sakura.ne.jp> <15e42fd1-055d-28f6-5e24-1448e16954a9@selasky.org> <20170605174930.GA6259@brick> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20170605174930.GA6259@brick> User-Agent: Mutt/1.8.2 (2017-04-18) X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 08 Jun 2017 21:18:42 -0000 On 0605T1849, Edward Tomasz Napierała wrote: > On 0604T0952, Hans Petter Selasky wrote: > > On 06/04/17 09:39, Tomoaki AOKI wrote: > > > Hi > > > > > > One possibility would be to make it MD build-time OTIONS, > > > defaulting 1M on regular systems and 128k on smaller systems. > > > > > > Of course I guess making it a tunable (or sysctl) would be best, > > > though. > > > > > > > Hi, > > > > A tunable sysctl would be fine, but beware that commonly used firmware > > out there produced in the millions might hang in a non-recoverable way > > if you exceed their "internal limits". Conditionally lowering this > > definition is fine, but increasing it needs to be carefully verified. > > > > For example many USB devices are only tested with OS'es like Windows and > > MacOS and if these have any kind of limitation on the SCSI transfer > > sizes, it is very likely many devices out there do not support any > > larger transfer sizes either. > > FWIW, when testing cfiscsi(4) with Windows and OSX I've noticed > that both issue 1MB requests. I wouldn't be surprised if they avoided > doing that for older devices, depending on eg the SCSI version reported > by device. Erm, this was obviously - or perhaps not - say: when testing cfumass(4). As in, Windows and OSX both seem to issue 1MB requests to USB Mass Storage devices.