Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965020AbaDKNz5 (ORCPT ); Fri, 11 Apr 2014 09:55:57 -0400 Received: from merlin.infradead.org ([205.233.59.134]:39775 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934289AbaDKNzy (ORCPT ); Fri, 11 Apr 2014 09:55:54 -0400 Message-Id: <20140411135218.181563050@infradead.org> User-Agent: quilt/0.60-1 Date: Fri, 11 Apr 2014 15:42:44 +0200 From: Peter Zijlstra To: mingo@kernel.org, tglx@linutronix.de, luto@amacapital.net, nicolas.pitre@linaro.org, daniel.lezcano@linaro.org, peterz@infradead.org, umgwanakikbuti@gmail.com Cc: linux-kernel@vger.kernel.org, Richard Henderson Subject: [RFC][PATCH 1/8] sched,idle,alpha: Switch from TS_POLLING to TIF_POLLING_NRFLAG References: <20140411134243.160989490@infradead.org> Content-Disposition: inline; filename=peterz-ts_polling-alpha.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Standardize the idle polling indicator to TIF_POLLING_NRFLAG such that both TIF_NEED_RESCHED and TIF_POLLING_NRFLAG are in the same word. This will allow us, using fetch_or(), to both set NEED_RESCHED and check for POLLING_NRFLAG in a single operation and avoid pointless wakeups. Changing from the non-atomic thread_info::status flags to the atomic thread_info::flags shouldn't be a big issue since most polling state changes were followed/preceded by a full memory barrier anyway. Cc: Thomas Gleixner Cc: Andy Lutomirski Cc: Richard Henderson Signed-off-by: Peter Zijlstra --- arch/alpha/include/asm/thread_info.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/arch/alpha/include/asm/thread_info.h +++ b/arch/alpha/include/asm/thread_info.h @@ -73,12 +73,14 @@ register struct thread_info *__current_t #define TIF_SYSCALL_AUDIT 4 /* syscall audit active */ #define TIF_DIE_IF_KERNEL 9 /* dik recursion lock */ #define TIF_MEMDIE 13 /* is terminating due to OOM killer */ +#define TIF_POLLING_NRFLAG 14 /* idle is polling for TIF_NEED_RESCHED */ #define _TIF_SYSCALL_TRACE (1<