Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 6 Mar 2003 12:47:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 6 Mar 2003 12:47:11 -0500 Received: from neon-gw-l3.transmeta.com ([63.209.4.196]:16649 "EHLO neon-gw.transmeta.com") by vger.kernel.org with ESMTP id ; Thu, 6 Mar 2003 12:47:09 -0500 Date: Thu, 6 Mar 2003 09:55:07 -0800 (PST) From: Linus Torvalds To: Alan Cox cc: Ingo Molnar , Jeff Garzik , Andrew Morton , , Linux Kernel Mailing List Subject: Re: [patch] "HT scheduler", sched-2.5.63-B3 In-Reply-To: <1046976597.17715.93.camel@irongate.swansea.linux.org.uk> Message-ID: 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: 1783 Lines: 37 On 6 Mar 2003, Alan Cox wrote: > > X isnt special at all. Research OS people have done stuff like time transfers > but I've not seen that in a production OS. In that situation an interactive > task blocking on a server hands on some of its interactiveness to whoever > services the request. This is what I really wanted to do - give the interactivity away at blocking time. However, there's usually no sane way to do that, since we don't know a-priori who we are blocking _for_. We could try to transfer it in the unix domain socket sleep case to whoever is waiting at the other end, but that's actually quite complex and ends up having each sleep entry somehow inform the subsystem it is sleeping on that it wants to give interactivity to the other end. The thing about wakeups is that it's an "illogical" place to give the bonus ("it's too late to give the server a bonus _now_, I wanted it when I went to sleep"), but it's the _trivial_ place to give it. It also (I'm convinced) is actually in the end exactly equivalent to giving the bonus at sleep time - in the steady state picture. In the single-transfer case it is wrong, but the single transfer case doesn't matter - the interactivity bonus isn't a "immediate shot of caffeine into the bloodstream" anyway. The interactivity bonus is supposed to help over time, so the only thing that matters is really the steady state. But the proof is in the pudding. Does this actually make things appear "nicer" to people? Or is it just another wanking session? 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/