From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Gleixner Subject: Re: suspend blockers & Android integration Date: Sun, 6 Jun 2010 02:19:40 +0200 (CEST) Message-ID: References: <20100603193045.GA7188@elte.hu> <20100603232302.GA16184@elte.hu> <1275644619.27810.39462.camel@twins> <201006050138.30859.rjw@sisk.pl> Mime-Version: 1.0 Content-Type: MULTIPART/MIXED; BOUNDARY="8323328-1891524831-1275783585=:2933" Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: =?ISO-8859-15?Q?Arve_Hj=F8nnev=E5g?= Cc: "Rafael J. Wysocki" , Peter Zijlstra , Ingo Molnar , tytso@mit.edu, Brian Swetland , Neil Brown , Alan Stern , Felipe Balbi , LKML , Florian Mickler , Linux OMAP Mailing List , Linux PM , Alan Cox , James Bottomley , Linus Torvalds , Kevin Hilman , "H. Peter Anvin" , Arjan van de Ven List-Id: linux-omap@vger.kernel.org This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. --8323328-1891524831-1275783585=:2933 Content-Type: TEXT/PLAIN; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT On Sat, 5 Jun 2010, Arve Hjønnevåg wrote: > 2010/6/5 Thomas Gleixner : > >> > Well, that's simply an application bug which sucks battery with or > >> > without suspend blockers. So it's unrelated to the freezing of > >> > untrusted apps while a trusted app still works in the background > >> > before allowing the machine to suspend. > >> > > >> > >> It is not unrelated if the trusted app has stopped working but still > >> blocks suspend. The battery drains when you combine them. > > > > What you are describing is a problem which is not solvable either way. > > If you take the lock and do not release it you're not going to > > suspend. I never claimed that any other mechanism resolves this. > > > Whether you claimed it or not, this is the only case where using > cgroups would have a significant power saving over what we get with > suspend. The trusted app is idle and the untrusted app is frozen, so > we enter a low power mode from idle. Nothing else was what I said and depending on the usage pattern this can be significant. Just you converted a perfectly sensible technical argument into a quibble about BUGs in applicatins which are not confinable by defintion. > > But this is not related to the fact that freezing crap while running a > > sane background task is going to save you power vs. an approach where > > running a sane background task allows crap to consume power unconfined > > until it is done. > > > If the task that is blocking suspend is using the cpu anyway, then the > bad app does not increase the power consumption nearly as much as if > the task that blocked suspend is idle. That's utter bullshit. If the app missed to release the supsend blocker then your crappy "while(1);" app is killing you in no time, while the same frozen crappy "while(1);" does no harm at all. Thanks, tglx --8323328-1891524831-1275783585=:2933--