Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756301Ab0LERPu (ORCPT ); Sun, 5 Dec 2010 12:15:50 -0500 Received: from mailout-de.gmx.net ([213.165.64.22]:55872 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with SMTP id S1756039Ab0LERPt (ORCPT ); Sun, 5 Dec 2010 12:15:49 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX18xq7JmCZExA/UWypiiEvcWqU/QfCda/P+Kk+/Xed NJ9+IWCdc+MrVY Subject: Re: [PATCH v4] Regression: sched: automated per session task groups From: Mike Galbraith To: Alan Cox Cc: Nikos Chantziaras , linux-kernel@vger.kernel.org In-Reply-To: <1291568977.7521.75.camel@marge.simson.net> References: <1289783580.495.58.camel@maggy.simson.net> <1289811438.2109.474.camel@laptop> <1289820766.16406.45.camel@maggy.simson.net> <1289821590.16406.47.camel@maggy.simson.net> <20101115125716.GA22422@redhat.com> <1289856350.14719.135.camel@maggy.simson.net> <20101116130413.GA29368@redhat.com> <1289917109.5169.131.camel@maggy.simson.net> <20101116150319.GA3475@redhat.com> <1289922108.5169.185.camel@maggy.simson.net> <20101116172804.GA9930@elte.hu> <1290281700.28711.9.camel@maggy.simson.net> <20101205151220.0c532c94@pyx> <1291568388.7521.67.camel@marge.simson.net> <1291568977.7521.75.camel@marge.simson.net> Content-Type: text/plain Date: Sun, 05 Dec 2010 18:15:40 +0100 Message-Id: <1291569340.8219.3.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1719 Lines: 34 On Sun, 2010-12-05 at 18:09 +0100, Mike Galbraith wrote: > On Sun, 2010-12-05 at 17:59 +0100, Mike Galbraith wrote: > > On Sun, 2010-12-05 at 15:12 +0000, Alan Cox wrote: > > > > > As soon as you do that from the same terminal that you're going to > > > > > launch the "make" from, you're back to total lossage. Are you going > > > > > to explain to a student that "oh, you need to create a new > > > > > gnome-terminal tab and launch firefox from that"? > > > > > > > > Btw, most people don't do that anymore. They don't use terminals. They > > > > > > Its a regression for those who do - and often have good reason to do. > > > This is of course why you don't put policy in the kernel and the original > > > patch was bogus anyway. > > > > What is a very clear regression is a threaded app (say firefox) vs a > > single threaded app, particularly on UP. The per thread scheduling > > model wins hands down there, because the scheduler very heavily favors > > the threaded application. Take that unfairness away, and you have an > > undeniable regression. Yes, it's not black and white, never is. > > P.S. You also have an obvious _progression_ from the perspective of the > single threaded application, which may just as well be interactive. P.P.S :) systemd will have the same regressions/progressions. It doesn't matter one whit whether it's kernel/userland making policy. If distro-X includes either one, or neither, they are guaranteed to be wrong :) -- 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/