From owner-freebsd-stable@freebsd.org Tue Jan 30 07:11:29 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D31F9EDE936 for ; Tue, 30 Jan 2018 07:11:29 +0000 (UTC) (envelope-from Andre.Albsmeier@siemens.com) Received: from goliath.siemens.de (goliath.siemens.de [192.35.17.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "goliath.siemens.de", Issuer "Siemens Issuing CA Internet Server 2017" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 3330A7F556; Tue, 30 Jan 2018 07:11:28 +0000 (UTC) (envelope-from Andre.Albsmeier@siemens.com) Received: from mail2.siemens.de (mail2.siemens.de [139.25.208.11]) by goliath.siemens.de (8.15.2/8.15.2) with ESMTPS id w0U7BQET031924 (version=TLSv1.2 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 30 Jan 2018 08:11:26 +0100 Received: from curry.mchp.siemens.de (curry.mchp.siemens.de [139.25.40.130]) by mail2.siemens.de (8.15.2/8.15.2) with ESMTP id w0U7BOl8004256; Tue, 30 Jan 2018 08:11:25 +0100 Received: (from user@localhost) by curry.mchp.siemens.de (8.15.2/8.15.2) id w0U7BOLi032571; Date: Tue, 30 Jan 2018 08:11:23 +0100 From: Andre Albsmeier To: Mike Karels Cc: Dimitry Andric , Andre Albsmeier , freebsd-stable@freebsd.org Subject: Re: i386 with 4GB RAM: less than 2GB available on A2SAV (Intel Atom E3940) Message-ID: <20180130071123.GB43715@bali> References: <201801281632.w0SGWiui055204@mail.karels.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201801281632.w0SGWiui055204@mail.karels.net> User-Agent: Mutt/1.7.2 (2016-11-26) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.25 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 30 Jan 2018 07:11:30 -0000 On Sun, 28-Jan-2018 at 10:32:44 -0600, Mike Karels wrote: > > On 28 Jan 2018, at 15:57, Andre Albsmeier = > > wrote: > > > I have a lot of machines running with 4 GB physical RAM and, for > > > some reasons, I still have to use a 32 bits OS. > > >=20 > > > All of them show something between 3 and 3.5 GB of RAM available > > > in dmesg but the brand new Supermicro A2SAV really shocked me: > > >=20 > > > FreeBSD 11.1-STABLE #0: Mon Jan 15 06:57:10 CET 2018 > > > ... > > > real memory =3D 4294967296 (4096 MB) > > > avail memory =3D 1939558400 (1849 MB) > > > ... > > >=20 > > > So do people have any ideas how I might get a bit closer to at least > > > 3 GB? I assume there are no FreeBSD knobs which might help but hope > > > dies last... > > > This is a common problem on i386. Most likely some ranges are reserved > > for I/O mappings, such as video cards. If you boot with -v, I think the > > kernel prints an overview of the physical ram chunks available? I don't > > know of any other way to get such an overview. > > > Another option is to try PAE, but I have no idea how stable that is... > > > -Dimitry > > I suspect that the unavailable RAM has been mapped above 4 GB by the BIOS. > > About PAE: at $JOB, we have a FreeBSD 8.2 system that has been running > PAE reliably since 8.2 was new. Also, we ship amd64 systems that run > mostly 32-bit binaries, which works well. But can the entire userland be 32 bit only? Maybe I'll try the PAE thing... -Andre