From patchwork Wed Sep 13 20:08:20 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Davidlohr Bueso X-Patchwork-Id: 9952027 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AE31D60360 for ; Wed, 13 Sep 2017 20:10:52 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A229228D27 for ; Wed, 13 Sep 2017 20:10:52 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 992B528C53; Wed, 13 Sep 2017 20:10:52 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 488C028D1A for ; Wed, 13 Sep 2017 20:10:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752326AbdIMUKh (ORCPT ); Wed, 13 Sep 2017 16:10:37 -0400 Received: from smtp2.provo.novell.com ([137.65.250.81]:48772 "EHLO smtp2.provo.novell.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751976AbdIMUIf (ORCPT ); Wed, 13 Sep 2017 16:08:35 -0400 Received: from linux-80c1.suse (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by smtp2.provo.novell.com with ESMTP (TLS encrypted); Wed, 13 Sep 2017 14:08:32 -0600 From: Davidlohr Bueso To: mingo@kernel.org, peterz@infradead.org, pbonzini@redhat.com Cc: npiggin@gmail.com, paulmck@linux.vnet.ibm.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org, dave@stgolabs.net, Davidlohr Bueso Subject: [PATCH 3/7] kvm,lapic: Justify use of swait_activate() Date: Wed, 13 Sep 2017 13:08:20 -0700 Message-Id: <20170913200824.28067-4-dave@stgolabs.net> X-Mailer: git-send-email 2.12.0 In-Reply-To: <20170913200824.28067-1-dave@stgolabs.net> References: <20170913200824.28067-1-dave@stgolabs.net> Sender: kvm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A comment might serve future readers. Signed-off-by: Davidlohr Bueso --- arch/x86/kvm/lapic.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c index aaf10b6f5380..69c5612be786 100644 --- a/arch/x86/kvm/lapic.c +++ b/arch/x86/kvm/lapic.c @@ -1324,6 +1324,10 @@ static void apic_timer_expired(struct kvm_lapic *apic) atomic_inc(&apic->lapic_timer.pending); kvm_set_pending_timer(vcpu); + /* + * For x86, the atomic_inc() is serialized, thus + * using swait_active() is safe. + */ if (swait_active(q)) swake_up(q);