From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751404AbdGRHL0 (ORCPT ); Tue, 18 Jul 2017 03:11:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:59763 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751356AbdGRHLX (ORCPT ); Tue, 18 Jul 2017 03:11:23 -0400 Subject: Re: [Xen-devel] [PATCH v1] xen/grant-table: log the lack of grants To: Wengang Wang , xen-devel@lists.xensource.com, linux-kernel@vger.kernel.org Cc: junxiao.bi@oracle.com References: <20170707182344.9646-1-wen.gang.wang@oracle.com> From: Juergen Gross Message-ID: <3938171e-1f90-613f-7337-b17984a2aa66@suse.com> Date: Tue, 18 Jul 2017 09:11:20 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.2.1 MIME-Version: 1.0 In-Reply-To: <20170707182344.9646-1-wen.gang.wang@oracle.com> Content-Type: text/plain; charset=utf-8 Content-Language: de-DE Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 07/07/17 20:23, Wengang Wang wrote: > log a message when we enter this situation: > 1) we already allocated the max number of available grants from hypervisor > and > 2) we still need more (but the request fails because of 1)). > > Sometimes the lack of grants causes IO hangs in xen_blkfront devices. > Adding this log would help debuging. > > Signed-off-by: Wengang Wang > Reviewed-by: Konrad Rzeszutek Wilk > Reviewed-by: Junxiao Bi Reviewed-by: Juergen Gross Thanks, Juergen