Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756881Ab3J1QSp (ORCPT ); Mon, 28 Oct 2013 12:18:45 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:33592 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756539Ab3J1QSo (ORCPT ); Mon, 28 Oct 2013 12:18:44 -0400 Message-ID: <526E8E62.7070700@codeaurora.org> Date: Mon, 28 Oct 2013 09:18:42 -0700 From: Stephen Boyd User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.0.1 MIME-Version: 1.0 To: Kevin Hilman , Frederic Weisbecker CC: linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com, linux-arm-kernel@lists.infradead.org, rmk@arm.linux.org.uk, paulmck@linux.vnet.ibm.com, tglx@linutronix.de, linux-tip-commits@vger.kernel.org Subject: Re: [tip:timers/core] ARM: Kconfig: allow full nohz CPU accounting References: <20131016121416.GD12773@localhost.localdomain> <20131018163740.GA21983@codeaurora.org> <526DBEAA.4030707@linaro.org> In-Reply-To: <526DBEAA.4030707@linaro.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2242 Lines: 48 On 10/27/13 18:32, Kevin Hilman wrote: > Hi Stephen, > > On 10/18/2013 09:37 AM, Stephen Boyd wrote: >> On 10/16, Frederic Weisbecker wrote: >>> On Thu, Oct 03, 2013 at 06:58:03AM -0700, tip-bot for Kevin Hilman wrote: >>>> Commit-ID: 31c1fc8187158cb80ccd57c19e024c55af901797 >>>> Gitweb: http://git.kernel.org/tip/31c1fc8187158cb80ccd57c19e024c55af901797 >>>> Author: Kevin Hilman >>>> AuthorDate: Mon, 16 Sep 2013 15:28:22 -0700 >>>> Committer: Frederic Weisbecker >>>> CommitDate: Mon, 30 Sep 2013 15:37:05 +0200 >>>> >>>> ARM: Kconfig: allow full nohz CPU accounting >>>> >>>> With the 64-bit requirement removed from VIRT_CPU_ACCOUNTING_GEN, >>>> allow ARM platforms to enable it. Since VIRT_CPU_ACCOUNTING_GEN is a >>>> dependency for full NO_HZ, this allows ARM platforms to enable full >>>> NO_HZ as well. >>> I realize that arm doesn't implement irq work raise. It hooks on the >>> timer to execute pending irq work. You'll need to implement arch_irq_work_raise() >>> and implement some sort of self IPI to trigger irq work. The full dynticks subsystem >>> relies on that to work correctly. It often use that to re-evaluate and possibly restart >>> the tick after scheduler, posix timer updates, etc... >>> >>> That notwithstanding that if you have no tick, tick based irq work can't >>> work. >>> >> Something like this? The only problem is that this latches on to >> the SMP support for IPIs. If CONFIG_SMP is disabled we won't get >> arch_irq_work_raise() but perhaps that isn't so big of a deal? Or >> we should think about exposing IPI support to UP systems on ARM. > Care to submit a proper patch for this to LAKML? or if you prefer I can > do it (keeping your authorship.) We need this for proper full NOHZ > support on ARM. Thanks. Sure no problem. Let me write up some sort of commit text and I'll send it off again. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation -- 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/