From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933164AbbD2QKj (ORCPT ); Wed, 29 Apr 2015 12:10:39 -0400 Received: from smtp02.citrix.com ([66.165.176.63]:51897 "EHLO SMTP02.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753589AbbD2QKh (ORCPT ); Wed, 29 Apr 2015 12:10:37 -0400 X-IronPort-AV: E=Sophos;i="5.11,671,1422921600"; d="scan'208";a="259956608" Message-ID: <5541027A.90206@citrix.com> Date: Wed, 29 Apr 2015 17:10:34 +0100 From: David Vrabel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Icedove/31.4.0 MIME-Version: 1.0 To: Boris Ostrovsky , , CC: , Subject: Re: [Xen-devel] [PATCH v3] xen: Suspend ticks on all CPUs during suspend References: <1430261180-15382-1-git-send-email-boris.ostrovsky@oracle.com> In-Reply-To: <1430261180-15382-1-git-send-email-boris.ostrovsky@oracle.com> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-DLP: MIA2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28/04/15 23:46, Boris Ostrovsky wrote: > Commit 77e32c89a711 ("clockevents: Manage device's state separately for > the core") decouples clockevent device's modes from states. With this > change when a Xen guest tries to resume, it won't be calling its > set_mode op which needs to be done on each VCPU in order to make the > hypervisor aware that we are in oneshot mode. > > This happens because clockevents_tick_resume() (which is an intermediate > step of resuming ticks on a processor) doesn't call clockevents_set_state() > anymore and because during suspend clockevent devices on all VCPUs (except > for the one doing the suspend) are left in ONESHOT state. As result, during > resume the clockevents state machine will assume that device is already > where it should be and doesn't need to be updated. > > To avoid this problem we should suspend ticks on all VCPUs during > suspend. Applied to for-linus-4.1b, thanks. David