Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758558AbYJVUFx (ORCPT ); Wed, 22 Oct 2008 16:05:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752630AbYJVUFo (ORCPT ); Wed, 22 Oct 2008 16:05:44 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:35716 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750944AbYJVUFo (ORCPT ); Wed, 22 Oct 2008 16:05:44 -0400 Subject: Re: sched: deep power-saving states From: Peter Zijlstra To: Arjan van de Ven Cc: Gregory Haskins , Steven Rostedt , Ingo Molnar , LKML , Jon Masters In-Reply-To: <20081022125508.2ccea6e1@infradead.org> References: <48FF2DDC.5010600@gmail.com> <20081022064738.05818670@infradead.org> <48FF3321.4060809@novell.com> <20081022070701.567f1c9a@infradead.org> <48FF3829.8040704@novell.com> <20081022073616.5eb150fa@infradead.org> <1224704992.20069.71.camel@twins> <20081022125508.2ccea6e1@infradead.org> Content-Type: text/plain Content-Transfer-Encoding: 7bit Date: Wed, 22 Oct 2008 22:05:25 +0200 Message-Id: <1224705925.20069.76.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.24.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1155 Lines: 29 On Wed, 2008-10-22 at 12:55 -0700, Arjan van de Ven wrote: > On Wed, 22 Oct 2008 21:49:52 +0200 > Peter Zijlstra wrote: > > > > This still leaves us with the worst case IRQ response as given by the > > deepest C state. Which might be un-desirable. > > that's a different problem in a different problem space. Ah right, so the only point was trying to wake shallow cpus so as to try and let deep cpus idle longer? > > jcm was, once upon a time, working on dynamically changing the idle > > routine, so that people who care about wakeup latency can run > > idle=poll while their application runs, and the acpi C state stuff > > when nobody cares. > > > > This could of course then be tied into the PM QoS stuff Mark has been > > doing. > > in fact you already have this *exactly* today; this isn't future > technology. Interesting, what knob do I turn to get idle=poll dynamically? -- 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/