Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261222AbVFAAwg (ORCPT ); Tue, 31 May 2005 20:52:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261225AbVFAAwg (ORCPT ); Tue, 31 May 2005 20:52:36 -0400 Received: from zlynx.org ([199.45.143.209]:27917 "EHLO 199.45.143.209") by vger.kernel.org with ESMTP id S261222AbVFAAwc (ORCPT ); Tue, 31 May 2005 20:52:32 -0400 Subject: Re: RT patch acceptance From: Zan Lynx To: Steven Rostedt Cc: Lee Revell , Andrea Arcangeli , Esben Nielsen , linux-kernel@vger.kernel.org, akpm@osdl.org, hch@infradead.org, dwalker@mvista.com, Ingo Molnar , Sven-Thorsten Dietrich , Andi Kleen , "Bill Huey (hui)" , Nick Piggin , James Bruce In-Reply-To: <1117582887.4749.6.camel@localhost.localdomain> References: <1117556283.2569.26.camel@localhost.localdomain> <20050531171143.GS5413@g5.random> <1117561379.2569.57.camel@localhost.localdomain> <20050531175152.GT5413@g5.random> <1117564192.2569.83.camel@localhost.localdomain> <20050531205424.GV5413@g5.random> <1117574551.5511.19.camel@localhost.localdomain> <1117576067.23573.16.camel@mindpipe> <1117582887.4749.6.camel@localhost.localdomain> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-rqn/vQ+1UrY7gIVF4GpT" Date: Tue, 31 May 2005 18:50:03 -0600 Message-Id: <1117587003.25017.56.camel@localhost> Mime-Version: 1.0 X-Mailer: Evolution 2.2.1.1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2861 Lines: 69 --=-rqn/vQ+1UrY7gIVF4GpT Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Tue, 2005-05-31 at 19:41 -0400, Steven Rostedt wrote: [snip] > True, but do they really know how good PREEMPT_RT is, compared to those > that develop it and the kernel? But I'm fighting to get PREEMPT_RT into > the kernel, since I really think it would be used by quite a lot in the > industry. Just not the normal Desktop user. I believe that if solid RT was available to the desktop user, it would be used in many desktop applications. It would definitely need to be easy to enable for non-root applications. Capabilities, SCHED_ISO_*, rlimits... Every media playback and recording application would like it. Games would love it, especially multi-threaded games. =20 [Stop reading here if you don't like games...] Right now, a game is a big solid event loop, and it prioritizes by doing the important things first in the loop, then maybe check the time and drop something less important if it is taking too long, like skipping a render frame in order to keep the sound and physics running at a smooth rate. But with multi-threaded games, the programmer loses a lot of scheduling control. He might like to run a 60Hz render thread, AI thread(s), sound thread and physics thread, but cannot because he can't guarantee they will stay in sync. Everything stops moving if the physics thread gets interrupted by a low-prio Folding@Home process for 200ms. Good RT would fix that, and multi-thread games would be great for multi-cpu, multi-core, hyper-thread systems. We should not have to shut down all our background applications to run a video game (or other high-interactive CPU hogs). It should run smooth as glass even with distributed computation or Gentoo system compiles running in the background. If you don't believe <10 milliseconds matter to a gamer, you haven't hung around with obsessive Quake3 players who tweak their mouse rates over 200Hz, disable frame sync and turn off texture maps and lighting, all to get that microscopic edge over the opponent. Tell them about being able to tweak the mouse and network interrupt priorities and set X and Quake3 to RT priority. They'll be all over it. --=20 Zan Lynx --=-rqn/vQ+1UrY7gIVF4GpT Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBCnQY7G8fHaOLTWwgRAt+SAJ4kltjI9lq797JbYn9U9xzFXV5yhwCfQuoP AgGov6nG7IxNC7elz/EY7Qc= =vMaP -----END PGP SIGNATURE----- --=-rqn/vQ+1UrY7gIVF4GpT-- - 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/