From mboxrd@z Thu Jan 1 00:00:00 1970 From: Holger =?iso-8859-1?q?Hoffst=E4tte?= Subject: Re: Suspend and the ceph clients Date: Thu, 15 May 2014 08:13:59 +0000 (UTC) Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Return-path: Received: from plane.gmane.org ([80.91.229.3]:44638 "EHLO plane.gmane.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752265AbaEOIOX (ORCPT ); Thu, 15 May 2014 04:14:23 -0400 Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1Wkqny-0000RB-6G for ceph-devel@vger.kernel.org; Thu, 15 May 2014 10:14:18 +0200 Received: from p5b007409.dip0.t-ipconnect.de ([91.0.116.9]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 15 May 2014 10:14:18 +0200 Received: from holger.hoffstaette by p5b007409.dip0.t-ipconnect.de with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Thu, 15 May 2014 10:14:18 +0200 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel@vger.kernel.org On Wed, 14 May 2014 15:07:44 -0700, Gregory Farnum wrote: > [..] > Unfortunately, I don't know anything about Linux's suspend > functionality or APIs, and my weak attempts at googling and grepping > aren't turning anything up. So a question to everybody: > > 2) What notifications does Linux send, and what filesystem mechanisms > does it invoke, when it is suspending? Is this what you're looking for? https://www.kernel.org/doc/Documentation/power/freezing-of-tasks.txt User space is usually controlled by ("legacy") pm-utils, which simply executes a bunch of scripts (packaged and user provided) in various stages. It works reasonably well but is of course fragile - typical scripted duct tape. systemd has its own (IMHO much less fragile) way of doing things: http://www.freedesktop.org/software/systemd/man/systemd-sleep.conf.html Hope this helps. -h