From owner-svn-src-all@freebsd.org Thu Apr 7 05:31:23 2016 Return-Path: Delivered-To: svn-src-all@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 71A5DB07FF8; Thu, 7 Apr 2016 05:31:23 +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 421CC1364; Thu, 7 Apr 2016 05:31:23 +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 u375VMGd041114; Thu, 7 Apr 2016 05:31:22 GMT (envelope-from sephe@FreeBSD.org) Received: (from sephe@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id u375VMS9041113; Thu, 7 Apr 2016 05:31:22 GMT (envelope-from sephe@FreeBSD.org) Message-Id: <201604070531.u375VMS9041113@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: sephe set sender to sephe@FreeBSD.org using -f From: Sepherosa Ziehau Date: Thu, 7 Apr 2016 05:31:22 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r297634 - head/sys/dev/hyperv/vmbus X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Apr 2016 05:31:23 -0000 Author: sephe Date: Thu Apr 7 05:31:22 2016 New Revision: 297634 URL: https://svnweb.freebsd.org/changeset/base/297634 Log: 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: head/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Modified: head/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c ============================================================================== --- head/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Thu Apr 7 04:23:25 2016 (r297633) +++ head/sys/dev/hyperv/vmbus/hv_vmbus_drv_freebsd.c Thu Apr 7 05:31:22 2016 (r297634) @@ -117,8 +117,12 @@ 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. */ - atomic_thread_fence_seq_cst(); + mb(); if (msg->header.message_flags.u.message_pending) { /* @@ -190,8 +194,12 @@ 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. */ - atomic_thread_fence_seq_cst(); + mb(); if (msg->header.message_flags.u.message_pending) { /*