From owner-freebsd-stable@FreeBSD.ORG Sun Dec 14 18:09:50 2014 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 4FC24210; Sun, 14 Dec 2014 18:09:50 +0000 (UTC) Received: from elvis.mu.org (elvis.mu.org [192.203.228.196]) by mx1.freebsd.org (Postfix) with ESMTP id 3EFA2B92; Sun, 14 Dec 2014 18:09:49 +0000 (UTC) Received: from [10.0.1.20] (c-76-21-10-192.hsd1.ca.comcast.net [76.21.10.192]) by elvis.mu.org (Postfix) with ESMTPSA id 2A954341F83D; Sun, 14 Dec 2014 10:09:43 -0800 (PST) Subject: Re: i386 PAE kernel works fine on 10-stable Mime-Version: 1.0 (Apple Message framework v1283) Content-Type: text/plain; charset=us-ascii From: Alfred Perlstein In-Reply-To: <1418579278.2026.9.camel@freebsd.org> Date: Sun, 14 Dec 2014 10:09:46 -0800 Content-Transfer-Encoding: quoted-printable Message-Id: References: <1418579278.2026.9.camel@freebsd.org> To: Ian Lepore X-Mailer: Apple Mail (2.1283) Cc: FreeBSD Stable X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 14 Dec 2014 18:09:50 -0000 On Dec 14, 2014, at 9:47 AM, Ian Lepore wrote: > This is an out of the blue FYI post to let people know that despite = all > the misinformation you'll run across if you search for information on > FreeBSD PAE support, it (still) works just fine. I've been using it > (for reasons related to our build system and products at $work) since > 2006, and I can say unequivocally that it works fine on 6.x, 8.x, and > now 10.x (and presumably on the odd-numbered releases too but I've = never > tried those). >=20 > In my most recent testing with 10-stable, I found it was compatible = with > drm2 and radeonkms drivers and I was able to run Xorg and gnome just > fine. All my devices, and apps, and even the linuxulator worked just > fine. >=20 > One thing that changed somewhere between 8.4 and 10.1 is that I had to > add a kernel tuning option to my kernel config: >=20 > option KVA_PAGES=3D768 # Default is 512 >=20 > I suspect that the most frequent use of PAE is on laptops that have = 4gb > and the default tuning is adequate for that. My desktop machine has > 12gb and I needed to bump up that value to avoid errors related to = being > unable to create new kernel stacks. >=20 There already is a #define that is bifurcated based on PAE in pmap.h: #ifndef KVA_PAGES #ifdef PAE #define KVA_PAGES 512 #else #define KVA_PAGES 256 #endif #endif Do you think it will harm things to apply your suggested default to this = file? -Alfred