Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754489AbZJESMs (ORCPT ); Mon, 5 Oct 2009 14:12:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754350AbZJESMr (ORCPT ); Mon, 5 Oct 2009 14:12:47 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:47456 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754337AbZJESMr (ORCPT ); Mon, 5 Oct 2009 14:12:47 -0400 Date: Mon, 5 Oct 2009 11:12:06 -0700 (PDT) From: Linus Torvalds X-X-Sender: torvalds@localhost.localdomain To: Jeff Chua cc: Linux Kernel , Andrew Morton , Hugh Dickins Subject: Re: 2.6.32-rc3: low mem - only 378MB on x86_32 with 64GB. Why? In-Reply-To: Message-ID: References: User-Agent: Alpine 2.01 (LFD 1184 2008-12-16) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 860 Lines: 29 On Mon, 5 Oct 2009, Jeff Chua wrote: > > I've 3 systems with 4GB, 16GB and 64GB all running 32bit with these set: Don't. 4GB is useable. 8GB is borderline. 16GB+ and nobody will care. > # with 64GB > total used free shared buffers cached > Mem: 63995 524 63470 0 4 365 > Low: 378 32 345 All your low memory is used for the 'struct page' arrays that describe everything else. > Anything I should do? Use a 64-bit CPU and kernel or limit your memory to 8GB or so. No ifs, buts and maybe's. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/