From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH 1/8] PM: Add suspend block api. Date: Fri, 30 Apr 2010 06:24:43 +0200 Message-ID: <4BDA5B8B.50004@kernel.org> References: <1272429119-12103-1-git-send-email-arve@android.com> <201004282250.44200.rjw@sisk.pl> <201004292316.14524.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <201004292316.14524.rjw@sisk.pl> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.linux-foundation.org Errors-To: linux-pm-bounces@lists.linux-foundation.org To: "Rafael J. Wysocki" Cc: Len Brown , linux-doc@vger.kernel.org, Oleg Nesterov , Jesse Barnes , linux-kernel@vger.kernel.org, Magnus Damm , linux-pm@lists.linux-foundation.org, Wu Fengguang , Andrew Morton List-Id: linux-pm@vger.kernel.org Hello, On 04/29/2010 11:16 PM, Rafael J. Wysocki wrote: >>> Also, we already have one PM workqueue. It is used for runtime PM, but I guess >>> it may be used just as well for the opportunistic suspend. It is freezable, >>> but would it hurt? >> >> No, it works, the freezable flag is just ignored when I call >> pm_suspend and I don't run anything else on the workqueue while >> threads are frozen. It does need to be a single threaded workqueue >> though, so make sure you don't just change that. > > Freezable workqueues have to be singlethread or else there will be unfixable > races, so you can safely assume things will stay as they are in this respect. Rafael, can you elaborate a bit more on this? Just in case I missed something while doing cmwq as it currently doesn't have such limit. Thanks. -- tejun