From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756475AbaEIOuU (ORCPT ); Fri, 9 May 2014 10:50:20 -0400 Received: from bombadil.infradead.org ([198.137.202.9]:41475 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756069AbaEIOuR convert rfc822-to-8bit (ORCPT ); Fri, 9 May 2014 10:50:17 -0400 Date: Fri, 9 May 2014 16:50:02 +0200 From: Peter Zijlstra To: Catalin Marinas Cc: James Hogan , "mingo@kernel.org" , Thomas Gleixner , "luto@amacapital.net" , "nicolas.pitre@linaro.org" , "daniel.lezcano@linaro.org" , "umgwanakikbuti@gmail.com" , LKML , Will Deacon , ARM Kernel List Subject: Re: [RFC][PATCH 6/8] sched,idle: Avoid spurious wakeup IPIs Message-ID: <20140509145002.GW2844@laptop.programming.kicks-ass.net> References: <20140411134243.160989490@infradead.org> <20140411135218.478299389@infradead.org> <20140509141520.GV2844@laptop.programming.kicks-ass.net> <20140509144034.GF7950@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <20140509144034.GF7950@arm.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, May 09, 2014 at 03:40:34PM +0100, Catalin Marinas wrote: > I wonder why we still need TIF_POLLING_NRFLAG for arm64. It was on arm > until commit 16a8016372c42c7628eb (sanitize tsk_is_polling()). On arm64 > we use wfi for idle or a firmware call but in both cases the assumption > is that we need an interrupt for waking up. > > So I think we should remove this macro for arm64. Does ARM64 support idle=poll? If so, you could keep it for that, otherwise it does indeed appear to be pointless. As to 32bit ARM, are there SMP chips which do not have WFI?