From owner-freebsd-hackers@FreeBSD.ORG Tue Oct 19 14:31:10 2010 Return-Path: Delivered-To: freebsd-hackers@FreeBSD.ORG Received: by hub.freebsd.org (Postfix, from userid 1233) id 30D851065670; Tue, 19 Oct 2010 14:31:10 +0000 (UTC) Date: Tue, 19 Oct 2010 14:31:10 +0000 From: Alexander Best To: Matthew Jacob Message-ID: <20101019143110.GA5802@freebsd.org> References: <20101018235318.GA87158@freebsd.org> <4CBCE67C.1070106@feral.com> <20101019103432.GA69208@freebsd.org> <4CBDA371.4080801@feral.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4CBDA371.4080801@feral.com> Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: SCSI_DELAY cleanup X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Oct 2010 14:31:10 -0000 On Tue Oct 19 10, Matthew Jacob wrote: > It would be an effective behavioral change for those of us who remove > that line. > Personally, I think 5 seconds is too long- even 2 seconds is more than > adequate even for moderately old 'other' hardware like scanners. > > For -current, why don't you simply remove all of the config lines and > leave the default at 2000ms? hmmm...i can only test the delay value on amd64. i was under the impression that archs like arm and mips need the longer delay. also at some locations in the code SCSI_DELAY is being set to 15000. i believe this is the case when certain drivers (cam, ahb, aha) get loaded as a kernel module, but i'm not sure. it looks like this: .if !defined(KERNBUILDDIR) opt_scsi.h: echo "#define SCSI_DELAY 15000" > ${.TARGET} .endif cheers. alex > > On 10/19/2010 3:34 AM, Alexander Best wrote: > >On Mon Oct 18 10, Matthew Jacob wrote: > >> What problem are you solving by this change? > >code cleanup. > > > >the scsi delay value currently defaults to 2000ms. however that doesn't > >make > >sense, since on almost all platforms it gets set to 5000ms in the default > >config. what's the purpose of having a default value, if it is much more > >often > >overwritten than actually used? > > > >that's why this patch changes the default scsi delay value to 5000ms. now > >all > >of the lines that were setting the scsi delay value to 5000ms can be > >removed. > >also default values should be chosen very conservatively. users can always > >lower the delay value via their kernel config or sysctl. > > > >cheers. > >alex > -- a13x