From owner-freebsd-stable@FreeBSD.ORG Wed Jan 26 17:37:38 2011 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6DD1D106564A for ; Wed, 26 Jan 2011 17:37:38 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 3E1998FC1B for ; Wed, 26 Jan 2011 17:37:38 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id C5CB446B03; Wed, 26 Jan 2011 12:37:37 -0500 (EST) Received: from jhbbsd.localnet (smtp.hudson-trading.com [209.249.190.9]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id CA94C8A009; Wed, 26 Jan 2011 12:37:36 -0500 (EST) From: John Baldwin To: freebsd-stable@freebsd.org Date: Wed, 26 Jan 2011 12:35:56 -0500 User-Agent: KMail/1.13.5 (FreeBSD/7.4-CBSD-20110107; KDE/4.4.5; amd64; ; ) References: <4D401192.3030400@it4pro.pl> <201101260806.10084.jhb@freebsd.org> <4D401F9C.6050402@it4pro.pl> In-Reply-To: <4D401F9C.6050402@it4pro.pl> MIME-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <201101261235.56856.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Wed, 26 Jan 2011 12:37:36 -0500 (EST) X-Virus-Scanned: clamav-milter 0.96.3 at bigwig.baldwin.cx X-Virus-Status: Clean X-Spam-Status: No, score=-1.9 required=4.2 tests=BAYES_00 autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on bigwig.baldwin.cx Cc: Bartosz Stec Subject: Re: top shows only half of realmem? X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Jan 2011 17:37:38 -0000 On Wednesday, January 26, 2011 8:20:28 am Bartosz Stec wrote: > W dniu 2011-01-26 14:06, John Baldwin pisze: > > On Wednesday, January 26, 2011 7:20:34 am Bartosz Stec wrote: > >> Guys, > >> > >> could someone explain me this? > >> > >> # sysctl hw.realmem > >> hw.realmem: 2139029504 > >> > >> top line shows: > >> > >> Mem: 32M Active, 35M Inact, 899M Wired, 8392K Cache, 199M Buf, 58M Free > >> > >> 32+35+899+8+199+58 = 1231MB > >> > >> Shouldn't that sum to all available ram? Or maybe I'm reading it wrong? > >> This machine has indeed 2GB of ram on board and showed in BIOS. > >> i386 FreeBSD 8.2-PRERELEASE #16: Mon Jan 17 22:28:53 CET 2011 > >> Cheers. > > First, don't include 'buf' as isn't a separate set of RAM, it is only a range > > of the virtual address space in the kernel. It used to be relevant when the > > buffer cache was separate from the VM page cache, but now it is mostly > > irrelevant (arguably it should just be dropped from top output). > > Thanks for the explanation. So 1231MB - 199MB Buf and we got about 1GB > of memory instead of 2B. > > > However, look at what hw.physmem says (and the realmem and availmem lines in > > dmesg). realmem is actually not that useful as it is not a count of the > > amount of memory, but the address of the highest memory page available. There > > can be less memory available than that due to "holes" in the address space for > > PCI memory BARs, etc. > > > OK, here you go: > # sysctl hw | grep mem > > hw.physmem: 2125893632 > hw.usermem: 1212100608 > hw.realmem: 2139029504 > hw.pci.host_mem_start: 2147483648 Humm, you should still have 2GB of RAM then. All the memory you set aside for ARC should be counted in the 'wired' count, so I'm not sure why you see 1GB of RAM rather than 2GB. -- John Baldwin