From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751430AbdALKHe (ORCPT ); Thu, 12 Jan 2017 05:07:34 -0500 Received: from terminus.zytor.com ([198.137.202.10]:38954 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751141AbdALKH2 (ORCPT ); Thu, 12 Jan 2017 05:07:28 -0500 Date: Thu, 12 Jan 2017 02:06:45 -0800 From: tip-bot for Pan Xinhui Message-ID: Cc: hpa@zytor.com, xinhui.pan@linux.vnet.ibm.com, torvalds@linux-foundation.org, peterz@infradead.org, linux-kernel@vger.kernel.org, mingo@kernel.org, tglx@linutronix.de Reply-To: hpa@zytor.com, xinhui.pan@linux.vnet.ibm.com, torvalds@linux-foundation.org, peterz@infradead.org, tglx@linutronix.de, mingo@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <1484035006-6787-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> References: <1484035006-6787-1-git-send-email-xinhui.pan@linux.vnet.ibm.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:locking/core] locking/pvqspinlock: Don't wait if vCPU is preempted Git-Commit-ID: 75437bb304b20a2b350b9a8e9f9238d5e24e12ba X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 75437bb304b20a2b350b9a8e9f9238d5e24e12ba Gitweb: http://git.kernel.org/tip/75437bb304b20a2b350b9a8e9f9238d5e24e12ba Author: Pan Xinhui AuthorDate: Tue, 10 Jan 2017 02:56:46 -0500 Committer: Ingo Molnar CommitDate: Thu, 12 Jan 2017 09:35:57 +0100 locking/pvqspinlock: Don't wait if vCPU is preempted If prev node is not in running state or its vCPU is preempted, we can give up our vCPU slices in pv_wait_node() ASAP. Signed-off-by: Pan Xinhui Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: longman@redhat.com Link: http://lkml.kernel.org/r/1484035006-6787-1-git-send-email-xinhui.pan@linux.vnet.ibm.com [ Fixed typos in the changelog, removed ugly linebreak from the code. ] Signed-off-by: Ingo Molnar --- kernel/locking/qspinlock_paravirt.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/locking/qspinlock_paravirt.h b/kernel/locking/qspinlock_paravirt.h index e3b5520..e6b2f7a 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -263,7 +263,7 @@ pv_wait_early(struct pv_node *prev, int loop) if ((loop & PV_PREV_CHECK_MASK) != 0) return false; - return READ_ONCE(prev->state) != vcpu_running; + return READ_ONCE(prev->state) != vcpu_running || vcpu_is_preempted(prev->cpu); } /*