Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932170AbWHYI0s (ORCPT ); Fri, 25 Aug 2006 04:26:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751334AbWHYI0s (ORCPT ); Fri, 25 Aug 2006 04:26:48 -0400 Received: from smtp106.mail.mud.yahoo.com ([209.191.85.216]:35680 "HELO smtp106.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S1751320AbWHYI0s (ORCPT ); Fri, 25 Aug 2006 04:26:48 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=EAgphnvdgM1hx/Yy2P9w/vUBHvc9dibmnkvTnlfLeyy0P/p/Fpav0SDSczVlYZaU2XqQJ/L2z/2qioGm4yT+aVEH+gtpsykI9me0+IlvwdTlkhWtrA8ej20KSCt7m/3NVEKuopciux2RgJEM6I9it9P3PPCmFRI+uk5UAMQtAGs= ; Message-ID: <44EEB425.8060707@yahoo.com.au> Date: Fri, 25 Aug 2006 18:26:13 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20051007 Debian/1.7.12-1 X-Accept-Language: en MIME-Version: 1.0 To: Arjan van de Ven CC: Jesse Barnes , linux-kernel@vger.kernel.org, len.brown@intel.com, Arjan van de Ven Subject: Re: [RFC] maximum latency tracking infrastructure References: <1156441295.3014.75.camel@laptopd505.fenrus.org> <200608241408.03853.jbarnes@virtuousgeek.org> <44EE1801.3060805@linux.intel.com> <44EE829C.10606@yahoo.com.au> <44EEAD8D.6010801@linux.intel.com> In-Reply-To: <44EEAD8D.6010801@linux.intel.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1213 Lines: 35 Arjan van de Ven wrote: > Nick Piggin wrote: >> Surely you would call set_acceptable_latency() *before* running such >> operation that requires the given latency? And that >> set_acceptable_latency >> would block the caller until all CPUs are set to wake within this >> latency. >> >> That would be the API semantics I would expect, anyway. > > > but that means it blocks, and thus can't be used in irq context Is that a problem? I guess it could be, but you don't want to give a false sense of security either. Having an explicit _nosync version may make that clear? > > (the usage model I imagine happens most is a set_acceptable_latency() > which can block during device init, > with either no or a very course limit, and a > modify_acceptable_latency(), which cannot block, from irq context or > device open) OK. You'd know more about that than I ;) -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com - 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/