Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751672AbaJPQGA (ORCPT ); Thu, 16 Oct 2014 12:06:00 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:20164 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751238AbaJPQF6 (ORCPT ); Thu, 16 Oct 2014 12:05:58 -0400 X-IronPort-AV: E=Sophos;i="5.04,733,1406592000"; d="scan'208";a="183215858" Message-ID: <543FEBC5.2050202@citrix.com> Date: Thu, 16 Oct 2014 17:01:09 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Icedove/24.5.0 MIME-Version: 1.0 To: , , CC: Chang Huaixin , , , , , Subject: Re: [Xen-devel] [PATCH] Input: xen-kbdfront - free grant table entry in xenkbd_disconnect_backend References: <1413423992-3005-1-git-send-email-hansechang@gmail.com> In-Reply-To: <1413423992-3005-1-git-send-email-hansechang@gmail.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit X-DLP: MIA1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/10/14 02:46, hansechang@gmail.com wrote: > From: Chang Huaixin > > xenkbd_disconnect_backend doesn't free grant table entry. > This bug affects live migration. > > xenkbd_disconnect_backend uses gnttab_end_foreign_access_ref > to handle grant table entry which doesn't really free an entry. > > Thus every time we do xenkbd_resume, grant table entry increses > by one. As an grant table entry occupies 8 bytes, an grant table > page has at most 512 entries. Every 512 times we do xenkdb_resume, > grant table pages increses by one. > > After around 3500 times of live migration, grant table pages > will increase by 7, causing too many pages to populate and hitting > max_pages limit when assigning pages.Thus assign_pages will fail, > so will live migration. Acked-by: David Vrabel This need to be send to the input subsystem maintainers. David -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/