From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nigel Cunningham Subject: Re: [PATCH 3/9] PM: suspend_block: Abort task freezing if a suspend_blocker is active. Date: Sat, 09 May 2009 10:12:23 +1000 Message-ID: <1241827943.19600.386.camel@nigel-laptop> References: <1241583529-5092-1-git-send-email-arve@android.com> <200905081640.44894.rjw@sisk.pl> <1241821626.19600.325.camel@nigel-laptop> <200905090101.02390.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <200905090101.02390.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: u.luckas@road.de, swetland@google.com, linux-pm@lists.linux-foundation.org List-Id: linux-pm@vger.kernel.org Hi. On Sat, 2009-05-09 at 01:01 +0200, Rafael J. Wysocki wrote: > On Saturday 09 May 2009, Nigel Cunningham wrote: > > Hi. > > > > On Fri, 2009-05-08 at 16:40 +0200, Rafael J. Wysocki wrote: > > > The timeout is actually a workaround for the problem that we don't > > > really > > > know if tasks are going to react to our freeze requests and how much time it is > > > going to take. The current value of 20 s was chosen after a number of > > > experiments showing that in some cases the freezing _was_ going to take so > > > much time. Of course the question is whether it makes sense to give up earlier > > > even if tasks would eventually freeze, but that's a different issue. > > > > What were the circumstances in which freezing could take 20s? > > Compiling the kernel with "make -j" on a dual core system IIRC. > > Generally, the situation in which there are many runnable tasks and new tasks > come and go etc. I haven't repeated this benchmark recently, though, so it's > probably worth doing again. > > Which has a little to do with the $subject patch IMO, because I think that > it's reasonable to stop freezing tasks as soon as we know that it won't be > necessary anyway. Yes, but it's still good to know. Regards, Nigel