From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Wed, 8 Sep 2004 23:55:03 +0200 From: Diego Calleja Subject: Re: swapping and the value of /proc/sys/vm/swappiness Message-Id: <20040908235503.3f01523a.diegocg@teleline.es> In-Reply-To: <36100000.1094677832@flay> References: <5860000.1094664673@flay> <20040908215008.10a56e2b.diegocg@teleline.es> <36100000.1094677832@flay> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 8BIT Sender: owner-linux-mm@kvack.org Return-Path: To: "Martin J. Bligh" Cc: riel@redhat.com, raybry@sgi.com, marcelo.tosatti@cyclades.com, kernel@kolivas.org, akpm@osdl.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, piggin@cyberone.com.au List-ID: El Wed, 08 Sep 2004 14:10:32 -0700 "Martin J. Bligh" escribio: > I really don't see any point in pushing the self-tuning of the kernel out > into userspace. What are you hoping to achieve? Well your own words explain it, I think. "it's all dependant on the workload", which means that only the user knows what he is going to do with the machine and that the kernel doesn't knows that, so the algoritms built in the kernel may be "not perfect" in their auto-tuning job. The point would be to be able to take decisions the kernel can't take because userspace would know better how the system should behave, say stupids things like "I want to have this set of tunables which make compile jobs 0.01% faster at 12:00 because at that time a cron job autocompiles cvs snapshots of some project, and at 6:00 those jobs have already finished so at that time I want a set of tunables optimized for my everyday desktop work which make everthing 0.01% slower but the system feels a 5% more reponsive". (well, for that a shell script is enought) Kernel however could try to adapt itself to those changes, and do it well...I don't really know. This came to my mind when I was thinking about irqbalance case, which was somewhat similar, I also remember a discussion about a "ktuned" in the mailing lists...I guess it's a matter of coding it and get some numbers :-/ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: aart@kvack.org