From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756557AbbIUK03 (ORCPT ); Mon, 21 Sep 2015 06:26:29 -0400 Received: from mo4-p04-ob.smtp.rzone.de ([81.169.146.178]:46312 "EHLO mo4-p04-ob.smtp.rzone.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756470AbbIUK02 (ORCPT ); Mon, 21 Sep 2015 06:26:28 -0400 X-RZG-CLASS-ID: mo04 X-RZG-AUTH: :P2EQZWCpfu+qG7CngxMFH1J+yackYocTD1iAi8x+OWtqWFmrC5F/k87927aG Date: Mon, 21 Sep 2015 12:26:26 +0200 From: Olaf Hering To: "K. Y. Srinivasan" , Greg KH Cc: linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, apw@canonical.com, vkuznets@redhat.com, jasowang@redhat.com Subject: Re: [PATCH 2/5] hv: add helpers to handle hv_util device state Message-ID: <20150921102626.GB4252@aepfle.de> References: <1442363823-22428-1-git-send-email-kys@microsoft.com> <1442363874-22508-1-git-send-email-kys@microsoft.com> <1442363874-22508-2-git-send-email-kys@microsoft.com> <20150921052532.GA24350@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20150921052532.GA24350@kroah.com> User-Agent: Mutt/1.5.24 (6503) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Sep 20, Greg KH wrote: > Just use a lock, that's what it is there for. How would that help? It might help because it enforces ordering. But that requires that all three utils get refactored to deal with the introduced locking. I will let KY comment on this. The issue I see with fcopy is that after or while fcopy_respond_to_host runs an interrupt triggers which also calls into hv_fcopy_onchannelcallback. It was most likely caused by a logic change in "recent" vmbus updates because this did not happen before. At least, the fcopy hang was not seen earler. Maybe the bug did just not trigger up to now for other reasons... Olaf