From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Zijlstra Subject: Re: [linux-pm] [PATCH 0/8] Suspend block api (version 8) Date: Fri, 28 May 2010 07:15:42 +0200 Message-ID: <1275023742.27810.7782.camel@twins> References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Alan Stern Cc: Matthew Garrett , Paul@smtp1.linux-foundation.org, LKML , Florian Mickler , Linux PM , Thomas Gleixner , Linux OMAP Mailing List , felipe.balbi@nokia.com, Alan Cox List-Id: linux-omap@vger.kernel.org On Thu, 2010-05-27 at 15:19 -0400, Alan Stern wrote: > On Thu, 27 May 2010, Peter Zijlstra wrote: > > > I still don't see how blocking applications will cause missed wakeups in > > anything but a buggy application at worst, and even those will > > eventually get the event when they unblock. > > > > What seems to be the confusion? > > During forced suspend, applications are block because they are frozen. > > When an event occurs, the application is notified somehow. But it > can't respond because it is frozen. Hence the event remains sitting in > a kernel queue and the system goes ahead and suspends anyway. The > application doesn't get thawed until the system wakes up at some > indefinite time in the future. If the kernel is awake to put things in queues, we're clearly not suspended and userspace is running ?!