Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756118AbbGUXAO (ORCPT ); Tue, 21 Jul 2015 19:00:14 -0400 Received: from mail-wi0-f176.google.com ([209.85.212.176]:37488 "EHLO mail-wi0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755689AbbGUXAM convert rfc822-to-8bit (ORCPT ); Tue, 21 Jul 2015 19:00:12 -0400 MIME-Version: 1.0 In-Reply-To: <20150722080827.5adcf5f1@noble> References: <1428254419-7334-1-git-send-email-pali.rohar@gmail.com> <3179448.TScsKEAuyR@vostro.rjw.lan> <20150720073226.GB25910@pali> <1715416.hWBvT0iLvO@vostro.rjw.lan> <20150722080827.5adcf5f1@noble> Date: Wed, 22 Jul 2015 01:00:10 +0200 X-Google-Sender-Auth: AhQBH3ryntmom1lQ0gqK6m9YvT0 Message-ID: Subject: Re: [PATCH v2 1/3] PM suspend/hibernate: Call notifier after freezing processes From: "Rafael J. Wysocki" To: NeilBrown Cc: "Rafael J. Wysocki" , =?UTF-8?Q?Pali_Roh=C3=A1r?= , Alasdair Kergon , Mike Snitzer , Neil Brown , Len Brown , Pavel Machek , dm-devel@redhat.com, linux-raid@vger.kernel.org, Linux Kernel Mailing List , "linux-pm@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1821 Lines: 47 Hi Neil, On Wed, Jul 22, 2015 at 12:08 AM, NeilBrown wrote: > On Mon, 20 Jul 2015 23:46:32 +0200 "Rafael J. Wysocki" > wrote: > >> On Monday, July 20, 2015 09:32:26 AM Pali Rohár wrote: >> > On Saturday 18 July 2015 01:27:15 Rafael J. Wysocki wrote: >> > > On Thursday, July 16, 2015 09:33:02 AM Pali Rohár wrote: >> > > > On Thursday 16 July 2015 03:02:03 Rafael J. Wysocki wrote: >> > > > > Also, if you're adding AFTER_FREEZE, it would be good to add BEFORE_THAW too >> > > > > for symmetry. >> > > > > >> > > > >> > > > But there is no use case for BEFORE_THAW. At least it is not needed for now. >> > > >> > > For your use case, a single function pointer would be sufficient too. >> > > >> > >> > What do you mean by single function pointer? kernel/power is part of >> > kernel image and dm-crypt is external kernel module. >> >> Well, if there is a function pointer in the core suspend code initially set to >> NULL and exported to modules such that the dm-crypt code can set it to >> something else, that should be sufficient, shouldn't it? > > As long as the dm-crypt module is never unloaded. OK, there is a race related to that. > And as long as no other module could very possible want functionality like this. Ever. The point was that there were no other users currently, so dm-crypt is going to be the only user for the time being. > If a module wants to be notified - the providing a notifier chain > really seems like the right thing to do... Well, so please see my last response in this thread. :-) Thanks, Rafael -- 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/