From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752366AbbIQQ2E (ORCPT ); Thu, 17 Sep 2015 12:28:04 -0400 Received: from e06smtp08.uk.ibm.com ([195.75.94.104]:46005 "EHLO e06smtp08.uk.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751723AbbIQQ2B (ORCPT ); Thu, 17 Sep 2015 12:28:01 -0400 X-Helo: d06dlp03.portsmouth.uk.ibm.com X-MailFrom: dingel@linux.vnet.ibm.com X-RcptTo: linux-kernel@vger.kernel.org From: Dominik Dingel To: Paolo Bonzini Cc: kvm@vger.kernel.org, linux-kernel@vger.kernel.org, Dominik Dingel Subject: [PATCH] kvm: fix preemption warnings in kvm_vcpu_block Date: Thu, 17 Sep 2015 18:27:50 +0200 Message-Id: <1442507270-67227-1-git-send-email-dingel@linux.vnet.ibm.com> X-Mailer: git-send-email 2.3.8 X-TM-AS-MML: disable X-Content-Scanned: Fidelis XPS MAILER x-cbid: 15091716-0033-0000-0000-0000041C8E84 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit f78195129963 ("kvm: add halt_poll_ns module parameter") calls, with enabled preemption, single_task_running. When CONFIG_DEBUG_PREEMPT is enabled that will result in a debug_smp_processor_id() call. Cc: # 4.2.x Signed-off-by: Dominik Dingel --- virt/kvm/kvm_main.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 54534de..ce67dd6 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1971,6 +1971,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) start = cur = ktime_get(); if (vcpu->halt_poll_ns) { + bool solo; ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns); do { @@ -1982,8 +1983,13 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu) ++vcpu->stat.halt_successful_poll; goto out; } + + preempt_disable(); + solo = single_task_running(); + preempt_enable(); + cur = ktime_get(); - } while (single_task_running() && ktime_before(cur, stop)); + } while (solo && ktime_before(cur, stop)); } for (;;) { -- 2.3.8