Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262942AbUKRTqs (ORCPT ); Thu, 18 Nov 2004 14:46:48 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262938AbUKRTob (ORCPT ); Thu, 18 Nov 2004 14:44:31 -0500 Received: from fw.osdl.org ([65.172.181.6]:38528 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S262935AbUKRTnx (ORCPT ); Thu, 18 Nov 2004 14:43:53 -0500 Date: Thu, 18 Nov 2004 11:43:41 -0800 (PST) From: Linus Torvalds To: Miklos Szeredi cc: hbryan@us.ibm.com, akpm@osdl.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, pavel@ucw.cz Subject: Re: [PATCH] [Request for inclusion] Filesystem in Userspace In-Reply-To: Message-ID: References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1279 Lines: 33 On Thu, 18 Nov 2004, Miklos Szeredi wrote: > > OK, sorry. I'd rephrase it then to say will the system allow _all_ > it's pages to be used for file data? Yup, pretty much. It's actually even _normal_ behaviour for many of the core users of shared files. People who really do databases get quite upset if you don't let them mmap as much memory as they want, because for them, they really tune their cache sizes for the size of memory, and they think the OS (and anything else, for that matter) just gets in their way. They want 99% of memory to be used for the shared mapping, and the remaining 1% for their code. (That's a bit extreme, but you get the idea). Historically, we've often tried to "partition" memory in various ways (ie "the buffer cache can only grow up to 40% of real memory" etc). It ends up being good for some things (watermarks etc), but almost ever time it ends up being bad as a hard _limit_. So yes, the kernel tends to let people do what they think they want to do. "Give them rope", 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/