From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754347AbXDTCA4 (ORCPT ); Thu, 19 Apr 2007 22:00:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754345AbXDTCA4 (ORCPT ); Thu, 19 Apr 2007 22:00:56 -0400 Received: from vms040pub.verizon.net ([206.46.252.40]:55159 "EHLO vms040pub.verizon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754019AbXDTCAz (ORCPT ); Thu, 19 Apr 2007 22:00:55 -0400 Date: Thu, 19 Apr 2007 22:00:48 -0400 From: Gene Heskett Subject: Re: Renice X for cpu schedulers In-reply-to: <200704200847.30516.kernel@kolivas.org> To: Con Kolivas Cc: Ingo Molnar , Andrew Morton , Nick Piggin , Linus Torvalds , Matt Mackall , William Lee Irwin III , Peter Williams , Mike Galbraith , ck list , Bill Huey , linux-kernel@vger.kernel.org, Arjan van de Ven , Thomas Gleixner Message-id: <200704192200.49189.gene.heskett@gmail.com> Organization: Organization? very little MIME-version: 1.0 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7bit Content-disposition: inline References: <20070417062621.GL2986@holomorphy.com> <200704191416.14374.gene.heskett@gmail.com> <200704200847.30516.kernel@kolivas.org> User-Agent: KMail/1.9.6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thursday 19 April 2007, Con Kolivas wrote: >On Friday 20 April 2007 04:16, Gene Heskett wrote: >> On Thursday 19 April 2007, Con Kolivas wrote: >> >> [and I snipped a good overview] >> >> >So yes go ahead and think up great ideas for other ways of metering out >> > cpu bandwidth for different purposes, but for X, given the absurd >> > simplicity of renicing, why keep fighting it? Again I reiterate that >> > most users of SD have not found the need to renice X anyway except if >> > they stick to old habits of make -j4 on uniprocessor and the like, and I >> > expect that those on CFS and Nicksched would also have similar >> > experiences. >> >> FWIW folks, I have never touched x's niceness, its running at the default >> -1 for all of my so-called 'tests', and I have another set to be rebooted >> to right now. And yes, my kernel makeit script uses -j4 by default, and >> has used -j8 just for effects, which weren't all that different from what >> I expected in 'abusing' a UP system that way. The system DID remain >> usable, not snappy, but usable. > >Gene, you're agreeing with me. You've shown that you're very happy with a > fair distribution of cpu and leaving X at nice 0. I was quite happy till Ingo's first patch came out, and it was even better, but I over-wrote it, and we're still figuring out just exactly what the magic twanger was that made it all click for me. OTOH, I don't think that patch passed muster with Mike G., either. We have obviously different workloads, and critical points in them. >> Having tried re-nicing X a while back, and having the rest of the system >> suffer in quite obvious ways for even 1 + or - from its default felt >> pretty bad from this users perspective. >> >> It is my considered opinion (yeah I know, I'm just a leaf in the hurricane >> of this list) that if X has to be re-niced from the 1 point advantage its >> had for ages, then something is basicly wrong with the overall scheduling, >> cpu or i/o, or both in combination. FWIW I'm using cfq for i/o. > >It's those who want X to have an unfair advantage that want it to do >something "special". Your agreement that it works fine at nice 0 shows you >don't want it to have an unfair advantage. Others who want it to have an >unfair advantage _can_ renice it if they desire. But if the cpu scheduler >gives X an unfair advantage within the kernel by default then you have _no_ >choice. If you leave the choice up to userspace (renice or not) then both >parties get their way. If you put it into the kernel only one party wins and >there is no way for the Genes (and Cons) of this world to get it back. > >Your opinion is as valuable as eveyone else's Gene. It is hard to get people >to speak on as frightening a playground as the linux kernel mailing list so >please do. In the FWIW category, htop has always told me that x is running at -1, not zero. Now, I have NDI where this is actually set at, so I'd have to ask stupid questions here if I did wanna play with it. Which I really don't, the last time I tried to -5 x, kde got a whole lot LESS responsive. But heck, 2.6.2 was freshly minted then too and I've long since forgot how I went about that unless I used htop to change it, the most likely scenario that I can picture at this late date. As for speaking my mind, yes, and I've been slapped down a few times, as much because I do a lot of bitching and microscopic amounts of patch submission. The only patch I ever submitted was for something in the floppy driver, way back in the middle of 2.2 days, rejected because I didn't know how to use the tools correctly. I didn't, so it was a shrug and my feelings weren't hurt. Some see that as an unbalanced set of books and I'm aware of it. OTOH, I think I do a pretty good job of playing the canary here, and that should be worth something if for no other reason than I can turn into a burr under somebodies saddle when things go all aglay. But I figure if its happening to me, then if I don't fuss, and that gotcha gets into a distro kernel, there are gonna be a hell of a lot more folks than me trying to grab the microphone. BTW, I'm glad you are feeling well enough to get into this again. -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) There cannot be a crisis next week. My schedule is already full. -- Henry Kissinger