From owner-svn-src-stable@freebsd.org Wed Jun 15 05:31:37 2016 Return-Path: Delivered-To: svn-src-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 51E16B720F4; Wed, 15 Jun 2016 05:31:37 +0000 (UTC) (envelope-from sephe@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id ED6672227; Wed, 15 Jun 2016 05:31:36 +0000 (UTC) (envelope-from sephe@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id u5F5Vad4001584; Wed, 15 Jun 2016 05:31:36 GMT (envelope-from sephe@FreeBSD.org) Received: (from sephe@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u5F5VaDX001583; Wed, 15 Jun 2016 05:31:36 GMT (envelope-from sephe@FreeBSD.org) Message-Id: <201606150531.u5F5VaDX001583@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: sephe set sender to sephe@FreeBSD.org using -f From: Sepherosa Ziehau Date: Wed, 15 Jun 2016 05:31:36 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r301914 - stable/10/sys/dev/hyperv/vmbus X-SVN-Group: stable-10 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.22 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 15 Jun 2016 05:31:37 -0000 Author: sephe Date: Wed Jun 15 05:31:35 2016 New Revision: 301914 URL: https://svnweb.freebsd.org/changeset/base/301914 Log: MFC 296180,297634 296180 hyperv: Use proper fence function to keep store-load order for msgs sfence only makes sure about the store-store order, which is not sufficient here. Use atomic_thread_fence_seq_cst() as suggested jhb and kib (a locked op in the nutshell, which should have the Reviewed by: jhb, kib, Jun Su MFC after: 1 week Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D5436 297634 hyperv: Use mb() instead of atomic_thread_fence_seq_cst() Since atomic_thread_fence_seq_cst() will become compiler fence on UP kernel. Reviewed by: kib, Dexuan Cui MFC after: 1 week Sponsored by: Microsoft OSTC Differential Revision: https://reviews.freebsd.org/D5852 Modified: stable/10/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c ============================================================================== --- stable/10/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Wed Jun 15 05:16:37 2016 (r301913) +++ stable/10/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Wed Jun 15 05:31:35 2016 (r301914) @@ -116,8 +116,12 @@ handled: * message_pending and EOMing. Otherwise, the EOMing will * not deliver any more messages * since there is no empty slot + * + * NOTE: + * mb() is used here, since atomic_thread_fence_seq_cst() + * will become compler fence on UP kernel. */ - wmb(); + mb(); if (msg->header.message_flags.u.message_pending) { /* @@ -186,8 +190,12 @@ hv_vmbus_isr(struct trapframe *frame) * message_pending and EOMing. Otherwise, the EOMing will * not deliver any more messages * since there is no empty slot + * + * NOTE: + * mb() is used here, since atomic_thread_fence_seq_cst() + * will become compler fence on UP kernel. */ - wmb(); + mb(); if (msg->header.message_flags.u.message_pending) { /*