Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756746Ab2KZRcY (ORCPT ); Mon, 26 Nov 2012 12:32:24 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:48007 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932294Ab2KZRMt (ORCPT ); Mon, 26 Nov 2012 12:12:49 -0500 From: Herton Ronaldo Krzesinski To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Andreas Herrmann , "Rafael J. Wysocki" , Herton Ronaldo Krzesinski Subject: [PATCH 207/270] cpufreq / powernow-k8: Remove usage of smp_processor_id() in preemptible code Date: Mon, 26 Nov 2012 14:58:17 -0200 Message-Id: <1353949160-26803-208-git-send-email-herton.krzesinski@canonical.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> References: <1353949160-26803-1-git-send-email-herton.krzesinski@canonical.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2736 Lines: 68 3.5.7u1 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Andreas Herrmann commit e4df1cbcc1f329e53a1fff7450b2229e0addff20 upstream. Commit 6889125b8b4e09c5e53e6ecab3433bed1ce198c9 (cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU) causes powernow-k8 to trigger a preempt warning, e.g.: BUG: using smp_processor_id() in preemptible [00000000] code: cpufreq/3776 caller is powernowk8_target+0x20/0x49 Pid: 3776, comm: cpufreq Not tainted 3.6.0 #9 Call Trace: [] debug_smp_processor_id+0xc7/0xe0 [] powernowk8_target+0x20/0x49 [] __cpufreq_driver_target+0x82/0x8a [] cpufreq_governor_performance+0x4e/0x54 [] __cpufreq_governor+0x8c/0xc9 [] __cpufreq_set_policy+0x1a9/0x21e [] store_scaling_governor+0x16f/0x19b [] ? cpufreq_update_policy+0x124/0x124 [] ? _raw_spin_unlock_irqrestore+0x2c/0x49 [] store+0x60/0x88 [] sysfs_write_file+0xf4/0x130 [] vfs_write+0xb5/0x151 [] sys_write+0x4a/0x71 [] system_call_fastpath+0x16/0x1b Fix this by by always using work_on_cpu(). Signed-off-by: Andreas Herrmann Signed-off-by: Rafael J. Wysocki Signed-off-by: Herton Ronaldo Krzesinski --- drivers/cpufreq/powernow-k8.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) diff --git a/drivers/cpufreq/powernow-k8.c b/drivers/cpufreq/powernow-k8.c index 1a40935..c671369 100644 --- a/drivers/cpufreq/powernow-k8.c +++ b/drivers/cpufreq/powernow-k8.c @@ -1223,14 +1223,7 @@ static int powernowk8_target(struct cpufreq_policy *pol, struct powernowk8_target_arg pta = { .pol = pol, .targfreq = targfreq, .relation = relation }; - /* - * Must run on @pol->cpu. cpufreq core is responsible for ensuring - * that we're bound to the current CPU and pol->cpu stays online. - */ - if (smp_processor_id() == pol->cpu) - return powernowk8_target_fn(&pta); - else - return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta); + return work_on_cpu(pol->cpu, powernowk8_target_fn, &pta); } /* Driver entry point to verify the policy and range of frequencies */ -- 1.7.9.5 -- 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/