From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752920AbZKIAtQ (ORCPT ); Sun, 8 Nov 2009 19:49:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751662AbZKIAtP (ORCPT ); Sun, 8 Nov 2009 19:49:15 -0500 Received: from e2.ny.us.ibm.com ([32.97.182.142]:37901 "EHLO e2.ny.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751406AbZKIAtP (ORCPT ); Sun, 8 Nov 2009 19:49:15 -0500 Date: Sun, 8 Nov 2009 16:49:24 -0800 From: "Paul E. McKenney" To: linux-kernel@vger.kernel.org Cc: akpm@linux-foundation.org, benh@kernel.crashing.org, anton@samba.org, paulus@samba.org, mingo@elte.hu Subject: [PATCH] Silence warning in rtas_event_scan() Message-ID: <20091109004924.GA28481@linux.vnet.ibm.com> Reply-To: paulmck@linux.vnet.ibm.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.15+20070412 (2007-04-11) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The rtas_event_scan() function uses smp_processor_id() without having disabled preemption, which results in a warning as follows: BUG: using smp_processor_id() in preemptible [00000000] code: events/0/9677 caller is .rtas_event_scan+0x9c/0x1ac Call Trace: [c00000001bb9fc20] [c0000000000102c8] .show_stack+0x70/0x184 (unreliable) [c00000001bb9fcd0] [c0000000002ebecc] .debug_smp_processor_id+0xe8/0x11c [c00000001bb9fd60] [c0000000000434f8] .rtas_event_scan+0x9c/0x1ac [c00000001bb9fdf0] [c000000000087494] .worker_thread+0x1d8/0x2a8 [c00000001bb9fed0] [c00000000008c41c] .kthread+0xa8/0xb4 [c00000001bb9ff90] [c0000000000272b0] .kernel_thread+0x54/0x70 However, this code is simply chosing a starting point for a traversal of all online CPUs, and under get_online_cpus() protection. Therefore, unprotected use of smp_processor_id() is permissible here. Change the smp_processor_id() to raw_smp_processor_id() to silence the warning. Signed-off-by: Paul E. McKenney --- arch/powerpc/platforms/pseries/rtasd.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/arch/powerpc/platforms/pseries/rtasd.c b/arch/powerpc/platforms/pseries/rtasd.c index b3cbac8..64394a6 100644 --- a/arch/powerpc/platforms/pseries/rtasd.c +++ b/arch/powerpc/platforms/pseries/rtasd.c @@ -405,7 +405,7 @@ static void rtas_event_scan(struct work_struct *w) get_online_cpus(); - cpu = next_cpu(smp_processor_id(), cpu_online_map); + cpu = next_cpu(raw_smp_processor_id(), cpu_online_map); if (cpu == NR_CPUS) { cpu = first_cpu(cpu_online_map); -- 1.5.2.5