Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752628AbaLADNn (ORCPT ); Sun, 30 Nov 2014 22:13:43 -0500 Received: from mga03.intel.com ([134.134.136.65]:7351 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752326AbaLADNm convert rfc822-to-8bit (ORCPT ); Sun, 30 Nov 2014 22:13:42 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,489,1413270000"; d="scan'208";a="616388603" From: "Liu, Chuansheng" To: Andy Lutomirski , Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" CC: Peter Zijlstra Subject: RE: [PATCH urgent v2] sched: Add missing rcu protection to wake_up_all_idle_cpus Thread-Topic: [PATCH urgent v2] sched: Add missing rcu protection to wake_up_all_idle_cpus Thread-Index: AQHQC++NLFlfGioHH0uJToFDDseD15x6ETtA Date: Mon, 1 Dec 2014 03:13:26 +0000 Message-ID: <27240C0AC20F114CBF8149A2696CBE4A01EE72A9@SHSMSX101.ccr.corp.intel.com> References: <729365dddca178506dfd0a9451006344cd6808bc.1417277372.git.luto@amacapital.net> In-Reply-To: <729365dddca178506dfd0a9451006344cd6808bc.1417277372.git.luto@amacapital.net> Accept-Language: zh-CN, en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.239.127.40] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > -----Original Message----- > From: Andy Lutomirski [mailto:luto@amacapital.net] > Sent: Sunday, November 30, 2014 12:14 AM > To: Ingo Molnar; Thomas Gleixner; linux-kernel@vger.kernel.org > Cc: Peter Zijlstra; Andy Lutomirski; Liu, Chuansheng > Subject: [PATCH urgent v2] sched: Add missing rcu protection to > wake_up_all_idle_cpus > > Locklessly doing is_idle_task(rq->curr) is only okay because of RCU > protection. The older variant of the broken code checked > rq->curr == rq->idle instead and therefore didn't need RCU. > > Fixes: f6be8af1c95d sched: Add new API wake_up_if_idle() to wake up the idle > cpu > Cc: Chuansheng Liu > Signed-off-by: Andy Lutomirski > --- Reviewed-by: Chuansheng Liu Thanks Andy. -- 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/