Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752056AbcCVUTT (ORCPT ); Tue, 22 Mar 2016 16:19:19 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57935 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751417AbcCVUTS (ORCPT ); Tue, 22 Mar 2016 16:19:18 -0400 Date: Tue, 22 Mar 2016 16:19:16 -0400 (EDT) Message-Id: <20160322.161916.402932899605112194.davem@redhat.com> To: imbrenda@linux.vnet.ibm.com Cc: labbott@fedoraproject.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 0/2] AF_VSOCK: Shrink the area influenced by prepare_to_wait From: David Miller In-Reply-To: <1458662752-2415-1-git-send-email-imbrenda@linux.vnet.ibm.com> References: <1458662752-2415-1-git-send-email-imbrenda@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.39]); Tue, 22 Mar 2016 20:19:18 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 727 Lines: 16 From: Claudio Imbrenda Date: Tue, 22 Mar 2016 17:05:50 +0100 > This patchset applies on net-next. > > I think I found a problem with the patch submitted by Laura Abbott > ( https://lkml.org/lkml/2016/2/4/711 ): we might miss wakeups. > Since the condition is not checked between the prepare_to_wait and the > schedule(), if a wakeup happens after the condition is checked but before > the sleep happens, and we miss it. ( A description of the problem can be > found here: http://www.makelinux.net/ldd3/chp-6-sect-2 ). > > The first patch reverts the previous broken patch, while the second patch > properly fixes the sleep-while-waiting issue. Series applied, thanks for following up on this.