Suspend block api (version 8)
in [Kernel]
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From: Peter Zijlstra on 26 May 2010 04:50 On Mon, 2010-05-24 at 02:46 +0200, Rafael J. Wysocki wrote: > On Saturday 22 May 2010, Arve Hjønnevåg wrote: > > This patch series adds a suspend-block api that provides the same > > functionality as the android wakelock api. This version adds a > > delay before suspending again if no suspend blockers were used > > during the last suspend attempt. > > Patches [1-6/8] applied to suspend-2.6/linux-next So you're going to merge this junk? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Arve Hjønnevåg on 26 May 2010 05:50 On Wed, May 26, 2010 at 1:47 AM, Peter Zijlstra <peterz(a)infradead.org> wrote: > On Tue, 2010-05-25 at 01:38 +0200, Rafael J. Wysocki wrote: >> > This of course will lead to a scattering of suspend blockers into any >> > drivers/subsystems considered "useful", which by looking through current >> > Android kernels is many of them. >> >> That depends on the maintainers of these subsystems, who still have the power >> to reject requested changes. > > So as a scheduler maintainer I'm going to merge a patch that does a > suspend_blocker when the runqueue's aren't empty... how about that? > I don't know if you are serious, since the all the runqueues are never empty while suspending, this would disable opportunistic suspend altogether. -- Arve Hj�nnev�g -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Brian Swetland on 26 May 2010 05:50 On Wed, May 26, 2010 at 2:45 AM, Peter Zijlstra <peterz(a)infradead.org> wrote: > On Wed, 2010-05-26 at 02:41 -0700, Arve Hjønnevåg wrote: >> On Wed, May 26, 2010 at 1:47 AM, Peter Zijlstra <peterz(a)infradead.org> wrote: >> > On Tue, 2010-05-25 at 01:38 +0200, Rafael J. Wysocki wrote: >> >> > This of course will lead to a scattering of suspend blockers into any >> >> > drivers/subsystems considered "useful", which by looking through current >> >> > Android kernels is many of them. >> >> >> >> That depends on the maintainers of these subsystems, who still have the power >> >> to reject requested changes. >> > >> > So as a scheduler maintainer I'm going to merge a patch that does a >> > suspend_blocker when the runqueue's aren't empty... how about that? >> > >> >> I don't know if you are serious, since the all the runqueues are never >> empty while suspending, this would disable opportunistic suspend >> altogether. > > So why again was this such a great scheme? Go fix your userspace to not > not run when not needed. Thanks for your constructive feedback. Brian -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Peter Zijlstra on 26 May 2010 05:50 On Wed, 2010-05-26 at 02:41 -0700, Arve Hjønnevåg wrote: > On Wed, May 26, 2010 at 1:47 AM, Peter Zijlstra <peterz(a)infradead.org> wrote: > > On Tue, 2010-05-25 at 01:38 +0200, Rafael J. Wysocki wrote: > >> > This of course will lead to a scattering of suspend blockers into any > >> > drivers/subsystems considered "useful", which by looking through current > >> > Android kernels is many of them. > >> > >> That depends on the maintainers of these subsystems, who still have the power > >> to reject requested changes. > > > > So as a scheduler maintainer I'm going to merge a patch that does a > > suspend_blocker when the runqueue's aren't empty... how about that? > > > > I don't know if you are serious, since the all the runqueues are never > empty while suspending, this would disable opportunistic suspend > altogether. So why again was this such a great scheme? Go fix your userspace to not not run when not needed. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Florian Mickler on 26 May 2010 05:50
On Wed, 26 May 2010 10:45:33 +0200 Peter Zijlstra <peterz(a)infradead.org> wrote: > On Mon, 2010-05-24 at 02:46 +0200, Rafael J. Wysocki wrote: > > On Saturday 22 May 2010, Arve Hj�nnev�g wrote: > > > This patch series adds a suspend-block api that provides the same > > > functionality as the android wakelock api. This version adds a > > > delay before suspending again if no suspend blockers were used > > > during the last suspend attempt. > > > > Patches [1-6/8] applied to suspend-2.6/linux-next > > So you're going to merge this junk? > > Yes. By now, everyone reading the posts should know all points. Raffael obviously was part of this discussion and came to the decision to merge it. My take of the discussion: _IF_ you want to suspend aggressively, I don't see another way. The thing is, this is a paradigm change. Suspend is not anymore controlled by userspace. In order to let userspace control/work with this scheme, it needs to know when a suspend will be successfull or poll: 1. kernel sees suspend may be possible on his side of things 2. kernel sends a message to userspace that i could be possibly possible to suspend, but it may well be that by the time userspace suspends it is not possible anymore 3. userspace decides to suspend. <- system suspends... or not ..-> 4. userspace retries ... retries ... retries ... And then you have the whole can of worms and races. Or you have the suspend-blocker scheme: 1. kernel sees suspend is possible. 2. kernel suspends. 3. bingo. Cheers, Flo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |