From owner-freebsd-questions@FreeBSD.ORG Tue May 31 00:39:57 2011 Return-Path: Delivered-To: questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id AA8E9106564A for ; Tue, 31 May 2011 00:39:57 +0000 (UTC) (envelope-from amvandemore@gmail.com) Received: from mail-fx0-f54.google.com (mail-fx0-f54.google.com [209.85.161.54]) by mx1.freebsd.org (Postfix) with ESMTP id 319BB8FC0C for ; Tue, 31 May 2011 00:39:56 +0000 (UTC) Received: by fxm11 with SMTP id 11so3879260fxm.13 for ; Mon, 30 May 2011 17:39:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:date :message-id:subject:from:to:cc:content-type; bh=0RXx3AR/e/TMpTdUFd/L0AYm1YWZATCEtdWStJBxrx0=; b=VLX8s2+JFqJ/BbtXRWrPjihtOcHPYXAwrMuhjz5eN+12xPtom+XB2om2MpviFTXpvg lyMmrEBeYbSgqocrlsfkDnBzT91oNF4qI1Ah4Ja0MGQGWe5WkRpbCguwOhPylZ93PNS9 ZPNvf3qOkyHGxwuQ3HxGsEmteSWAb1jPssT4Y= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; b=J1fqsMwHFRfavvMVQx2vatMmpHdlWXmwDLkMhnL5WBDmWdgaOgU02/n5wPVabXvIVA H6bBodGfphibdnf7AJ/EGjDTTD4z+ect+dERinUiQznApHe7q4vrKoBxTJtkJjwTHWlI nsz/hxxrlgrUzHnkQiz7PheGS6tjMYdoZAU4U= MIME-Version: 1.0 Received: by 10.223.144.136 with SMTP id z8mr6188556fau.31.1306802395918; Mon, 30 May 2011 17:39:55 -0700 (PDT) Received: by 10.223.118.148 with HTTP; Mon, 30 May 2011 17:39:55 -0700 (PDT) In-Reply-To: References: Date: Mon, 30 May 2011 19:39:55 -0500 Message-ID: From: Adam Vande More To: Warren Block Content-Type: text/plain; charset=ISO-8859-1 X-Content-Filtered-By: Mailman/MimeDel 2.1.5 Cc: questions@freebsd.org Subject: Re: I486_CPU or I586_CPU in kernel config X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 May 2011 00:39:57 -0000 On Mon, May 30, 2011 at 6:53 PM, Warren Block wrote: > sys/i386/i386/support.s is mentioned, but doesn't seem to have anything > explicitly specific for 586. There are some i686 entries. > > A test for cpu_class==CPUCLASS_586 in /sys/i386/isa/npx.c is mentioned in > the thread, but that check isn't in the current code. > Yeah, there doesn't seem to be concrete answer that's within my ability to diagnose. If you have some time and the burning desire, you could try some benchmark runs on each kernel to see if 686 is as preformant as 686/586. The first thread I posted seemed indicate a fairly noticeable slowdown when both were enabled, but there were perhaps problems with test methodology and of course that is quite old. Also seems like a good candidate question for hackers@ -- Adam Vande More