From owner-freebsd-arch@FreeBSD.ORG Sat Jun 11 23:51:02 2011 Return-Path: Delivered-To: freebsd-arch@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 36DE4106566B; Sat, 11 Jun 2011 23:51:02 +0000 (UTC) (envelope-from kmacybsd@gmail.com) Received: from mail-vw0-f54.google.com (mail-vw0-f54.google.com [209.85.212.54]) by mx1.freebsd.org (Postfix) with ESMTP id CB5348FC0A; Sat, 11 Jun 2011 23:51:01 +0000 (UTC) Received: by vws18 with SMTP id 18so4263083vws.13 for ; Sat, 11 Jun 2011 16:51:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; bh=7rfPbv1gEnspB/zo60Jf1ujTkOH0YftQuYQgCK/CRyE=; b=xSgJVhUiaIMcesYq9goEu6q+O70GotC1avm5B7GKD8/bdoahTnF4a3gFgspFPhTeOs 6vmBzcQai9e2ZSWOWcAoL7sBUFM8aGO3KBLnZMKVD4FCj6TnobVG/2KlUrB9Pipsy4yr gxCi0kuUtULK4phuowFWOtSdBtfo+8XQPCklY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type :content-transfer-encoding; b=mtTx8YrJdoVi5Wjn76rEIx1cPXOR7FV7xVPZWFw+W8VNOCYe+JzF7rpOpLZo8BXB7f YGNJOT4xeJfGLlSUwBhOLOQQRLZn5uJ8Ctidv4CRRklLLXpjuqzgWm5RQK9bMQHIed2X lmVTa7mZzssNrB4K2rFNsfAR4w8wJg3Hslk7w= MIME-Version: 1.0 Received: by 10.52.176.74 with SMTP id cg10mr3789854vdc.242.1307836260910; Sat, 11 Jun 2011 16:51:00 -0700 (PDT) Sender: kmacybsd@gmail.com Received: by 10.52.187.74 with HTTP; Sat, 11 Jun 2011 16:51:00 -0700 (PDT) In-Reply-To: <9349A935-F13D-4265-A59C-C1E9B35F2B73@bsdimp.com> References: <20110611171834.GA38142@zim.MIT.EDU> <20110611204326.GA51320@zim.MIT.EDU> <9349A935-F13D-4265-A59C-C1E9B35F2B73@bsdimp.com> Date: Sun, 12 Jun 2011 01:51:00 +0200 X-Google-Sender-Auth: 3yj2vn0kBXotehl8MCcl7F8CC5M Message-ID: From: "K. Macy" To: Warner Losh Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: mdf@freebsd.org, freebsd-arch@freebsd.org Subject: Re: [RFC] shipping kernels with default modules? X-BeenThere: freebsd-arch@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussion related to FreeBSD architecture List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 11 Jun 2011 23:51:02 -0000 >> Although I imagine that many drivers silently benefit from being >> loaded serially, to the best of my knowledge there is nothing >> architecturally requiring this apart from the fact that the scheduler >> isn't started until everything else tied to initialization happens. >> The absence of any sort of preemption was a bit of a thorn in my side >> back when I was working on "xenbus", as the linux implementation >> relies on the use of multiple thread contexts. I don't know how much >> effort to date has been put in to making boot fast. > > Right now newbus uses Giant for all its locking. =A0That's the biggest pr= oblem preventing parallel probe/attach. =A0Also, each and every bus calls p= robe, then calls attach for each device in sequence. =A0Fixing that would r= equire changing all the bus drivers. Fair enough. That would only be worthwhile in the presence of a coordinated push to shorten boot / reset times. Thanks