From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 6) Date: Mon, 17 May 2010 11:54:40 -0700 Message-ID: <87k4r24avj.fsf@deeprootsystems.com> References: <87hbm6cz90.fsf@deeprootsystems.com> <1274115885.4418.59.camel@mulgrave.site> <20100517174647.GA11512@gandalf> <1274119179.4418.68.camel@mulgrave.site> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pw0-f46.google.com ([209.85.160.46]:60141 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752266Ab0EQSyr (ORCPT ); Mon, 17 May 2010 14:54:47 -0400 In-Reply-To: <1274119179.4418.68.camel@mulgrave.site> (James Bottomley's message of "Mon\, 17 May 2010 13\:59\:39 -0400") Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: James Bottomley Cc: me@felipebalbi.com, Alan Stern , linux-omap@vger.kernel.org, Theodore Ts'o , Geoff Smith , Brian Swetland , Kernel development list , Oleg Nesterov , Mark Brown , Tejun Heo , Linux-pm mailing list , Arjan van de Ven , Liam Girdwood , Matthew Garrett James Bottomley writes: > The technical reason for wanting suspend blockers (as has been stated > more times than I can be bothered to go back and count) is that no-one > can currently produce a working model for race free kernel to user work > handoff At least I've never heard this technial reason stated so succinctly. It's not in the changelogs or in the Documentation file included. The way I undertand things, today's mainline kernel has a race-free kernel-to-user work handoff already. The possibility of races is introduced by the opportunistic suspend feature itself (patch 1.) The use of suspend blockers later in the series is needed to avoid the potential races introduced by opportunistic suspend. Kevin