From owner-freebsd-arch@FreeBSD.ORG Fri Jul 8 17:56:24 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 1F528106566B; Fri, 8 Jul 2011 17:56:24 +0000 (UTC) (envelope-from peter@wemm.org) Received: from mail-gx0-f182.google.com (mail-gx0-f182.google.com [209.85.161.182]) by mx1.freebsd.org (Postfix) with ESMTP id A9EF38FC13; Fri, 8 Jul 2011 17:56:23 +0000 (UTC) Received: by gxk28 with SMTP id 28so1099618gxk.13 for ; Fri, 08 Jul 2011 10:56:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=wemm.org; s=google; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=IaD/6y7bO9QK9/DI52iTN3lt58j/9Go8lfuQ410OseA=; b=YRpQJy7lJJRL1qUEYraGq+nEIlY9w/Ll7HdaMnGI1fFCudf7bI4hUnZQHvX75g4Kj0 P9EwHotUkiSxj7AD979nAsdk/0IwvWShdBuoNEBWh+6ARje5jEFt+PJcBBYGZ1Cmorsq o9oKmvxDNngMFD8rvFNLH7iaOOtrXWhJEFi4M= MIME-Version: 1.0 Received: by 10.90.200.1 with SMTP id x1mr2282645agf.58.1310147780977; Fri, 08 Jul 2011 10:56:20 -0700 (PDT) Received: by 10.91.183.18 with HTTP; Fri, 8 Jul 2011 10:56:20 -0700 (PDT) In-Reply-To: <201107081314.44128.jhb@freebsd.org> References: <20110708164844.GZ48734@deviant.kiev.zoral.com.ua> <201107081314.44128.jhb@freebsd.org> Date: Fri, 8 Jul 2011 10:56:20 -0700 Message-ID: From: Peter Wemm To: John Baldwin Content-Type: text/plain; charset=ISO-8859-1 Cc: Kostik Belousov , Attilio Rao , Sergey Kandaurov , freebsd-arch@freebsd.org Subject: Re: [PATCH] Add MAXCPU as a kernel config option and quality discussion on this 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: Fri, 08 Jul 2011 17:56:24 -0000 On Fri, Jul 8, 2011 at 10:14 AM, John Baldwin wrote: > On Friday, July 08, 2011 12:48:44 pm Kostik Belousov wrote: >> On Fri, Jul 08, 2011 at 05:37:17PM +0200, Attilio Rao wrote: >> > I've made this patch for making MAXCPU a kernel config option: >> > http://www.freebsd.org/~attilio/maxcpu_kernel_opt.diff >> > >> > Besides if this is a good idea or not (which I think it is) I want to >> > discuss this implementation and similar related problems. >> > In this case I've been forced to include opt_maxcpu.h in all the MD >> > param.h implementations. A similar case, KSTACK_PAGES, includes the >> > opt_kstack_pages.h only in the consumers. While this is possible for >> > KSTACK_PAGES, because there are very little consumers, it would be >> > impratical for MAXCPU. Besides, this is a very dangerous practice >> > IMHO: if a consumer fails to add opt_kstack_pages it may end up with a >> > faulty value, introducing a breakage that would go unnoticed. >> > >> > In my case, I think that including opt_maxcpu is a viable panacea, but >> > in general, after discussing with peter@, probabilly the better idea >> > would be having a centralized script that does pre-processing before >> > to start compiling and set with the right values all those constants >> > (something like genassym.c, but of course with a different purpose). >> > >> > What are your ideas on that? Do you think that including opt_maxcpu.h >> > would be acceptable for the time being? >> >> I vote for putting MAXCPU in opt_global.h. >> Why did you choosed separate opt header ? > > I agree this should just go into opt_global.h. I disagree. That makes it even harder to track down KLD's that depend on the correct value of MAXCPU. -- Peter Wemm - peter@wemm.org; peter@FreeBSD.org; peter@yahoo-inc.com; KI6FJV "All of this is for nothing if we don't go to the stars" - JMS/B5 "If Java had true garbage collection, most programs would delete themselves upon execution." -- Robert Sewell