From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Paul E. McKenney" Subject: Re: Attempted summary of suspend-blockers LKML thread, take three Date: Tue, 10 Aug 2010 17:44:15 -0700 Message-ID: <20100811004415.GI2379__26934.502591803$1281487604$gmane$org@linux.vnet.ibm.com> References: <20100808155719.GB3635@thunk.org> <20100808213821.GD3635@thunk.org> <20100809112453.77210acc@lxorguk.ukuu.org.uk> <20100809181638.GI3026@linux.vnet.ibm.com> <20100809201822.441905f7@lxorguk.ukuu.org.uk> <20100810044541.GA2817@linux.vnet.ibm.com> <20100810093849.138e2318@lxorguk.ukuu.org.uk> <20100810141107.GA12873@srcf.ucam.org> <20100810154405.475c2669@lxorguk.ukuu.org.uk> Reply-To: paulmck@linux.vnet.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20100810154405.475c2669@lxorguk.ukuu.org.uk> 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: Alan Cox Cc: david@lang.hm, Ted Ts'o , peterz@infradead.org, Brian Swetland , Felipe Contreras , linux-kernel@vger.kernel.org, James.Bottomley@suse.de, galibert@pobox.com, florian@mickler.org, menage@google.com, linux-pm@lists.linux-foundation.org, swmike@swm.pp.se, tglx@linutronix.de, arjan@infradead.org List-Id: linux-pm@vger.kernel.org On Tue, Aug 10, 2010 at 03:44:05PM +0100, Alan Cox wrote: > Which reminds me. I forgot a very important way that user space signals > the kernel as to its intents. > > The kernel can see whether code is sleeping by choice or sleeping because > someone blocked it (eg a page fault). The kernel also knows a lot about > the event being waited for (much more so in -rt than base). > > We don't capture all of that info but it seems it would advance progress > in the right direction to do so better. As one approach of many, this makes a great deal of sense. Thanx, Paul