Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755077Ab0DVN5I (ORCPT ); Thu, 22 Apr 2010 09:57:08 -0400 Received: from casper.infradead.org ([85.118.1.10]:42765 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754945Ab0DVN5F (ORCPT ); Thu, 22 Apr 2010 09:57:05 -0400 Subject: Re: Considerations on sched APIs under RT patch From: Peter Zijlstra To: Primiano Tucci Cc: rostedt@goodmis.org, linux-kernel@vger.kernel.org, tglx In-Reply-To: References: <1271804453.10448.168.camel@gandalf.stny.rr.com> <1271839772.1776.58.camel@laptop> <1271854016.10448.172.camel@gandalf.stny.rr.com> <1271879833.1776.186.camel@laptop> <1271883496.1776.263.camel@laptop> <1271942430.10448.196.camel@gandalf.stny.rr.com> Content-Type: text/plain; charset="UTF-8" Date: Thu, 22 Apr 2010 15:57:02 +0200 Message-ID: <1271944622.1776.349.camel@laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1252 Lines: 26 On Thu, 2010-04-22 at 15:50 +0200, Primiano Tucci wrote: > I knew this kind of solution based on OS-partitioning, but my group > and I are currently working on a Global-EDF scheduler, a unique > scheduler (and therefore a unique OS/Kernel) that is able to migrate > tasks between CPUs in order to maximize the global CPU usage. I would hardly call a global-edf scheduler unique. Its a well studied algorithm and even available in commercial SMP operating systems (hopefully soon Linux too, see SCHED_DEADLINE, which will approximate global-edf, much like the current SCHED_FIFO approximates global-fifo). > In order to to this we have a unique "super"-process (a > Meta-Scheduler) that needs to be able to control priority and affinity > of the managed tasks, without losing the control while doing this. Implementing this as userspace/middleware seems daft. But if your controlling process has a global affinity mask and runs as the highest available userspace process priority its still all valid. -- 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/