power: decrease idle suspend time for unplugged_suspend_ms, unplugged_off_ms and plugged_off_ms |
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Issue descriptionBased on metrics, Power.IdleTimeOnBattery, Power.IdleTimeAfterDimOnBattery & Power.IdleTimeAfterScreenOffOnBattery it appears a small percentage of users actually wake the device after a few seconds. In addition we have great resume times (1-2sec) so entering this low power state quicker doesn't have a huge penalty. I'd like to recommend we change powerd's unplugged_suspend_ms from 600000 (10min) to 420000 (7min) such that default unplugged idle times are: 300000 (5min) 360000 (6min) 420000 (7min) Now is the savings worth the effort? Lets say average user has 3 idle suspends/day. That means we'll spend 9min (3*3min) more in standby vs 'S0 idle off'. Power savings there would be ~6x so you could say you'll have ~1hr of additional standby from this change in absolute battery savings that would be 1hr / 14d*24h =~ 0.3% Or put another way its ~0.1% battery saved / idle suspend. Downsides include - Annoying users that would have waked in idle suspend from 7->10min (~10%) with longer wake - Increased standby entries that would expose bugs on those paths. If there's no debate on metrics interpretation (I put mine here: https://docs.google.com/document/d/1imnYPn9OiiiMja9gdmC-j3E_fguT2YKuPoMi3Anv6FY) and downside risk is minimal I'll plan to move forward w/ the change. A somewhat related proposal would be to also decrease dim -> idle further. UMA data there I believe also supports lowering that as users either respond to dim or don't so spending 60sec there may be too conservative. I'd recommend decrease of 60sec -> 30sec for that value. determining the power saved there is very platform dependent but if we estimate the platform is ~3W at idle screen on and 0.5W idle screen off we'd see another ~6x power improvement or 3min more standby per idle transition.
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Nov 9 2017
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Nov 21 2017
The following revision refers to this bug: https://chromium.googlesource.com/chromiumos/platform2/+/12c2e8db900a161718f25813b0efea317f10b484 commit 12c2e8db900a161718f25813b0efea317f10b484 Author: Todd Broch <tbroch@google.com> Date: Tue Nov 21 02:13:42 2017 power: decrease default unplugged idle off & suspend times. UMA data supports that active users typically react to either display dim or off cues quickly or are in fact idle and could move to lower power state. As such lets lower the times spent in each of these modes to hasten power savings which could be +20min of standby time or ~0.1% battery savings per idle transition. With change idle times are: unplugged_dim_ms = 300000 (5min no change) unplugged_off_ms = 330000 (from 6 -> 5.5min) unplugged_suspend_ms = 390000 (from 10 -> 6.5min) plugged_dim_ms = 420000 (7min no change) plugged_off_ms = 450000 (from 8 -> 7.5min) plugged_suspend_ms = 1800000 (30min no change) BUG= chromium:782725 TEST=manual, let device idle suspend & verify transistions occur at correct times. Change-Id: Ifb98ebbfc48a5e0e2ca1a7451a346ec3891c5e62 Reviewed-on: https://chromium-review.googlesource.com/760664 Commit-Ready: Todd Broch <tbroch@chromium.org> Tested-by: Todd Broch <tbroch@chromium.org> Reviewed-by: Dan Erat <derat@chromium.org> [modify] https://crrev.com/12c2e8db900a161718f25813b0efea317f10b484/power_manager/default_prefs/unplugged_suspend_ms [modify] https://crrev.com/12c2e8db900a161718f25813b0efea317f10b484/power_manager/default_prefs/unplugged_off_ms [modify] https://crrev.com/12c2e8db900a161718f25813b0efea317f10b484/power_manager/docs/inactivity_delays.md [modify] https://crrev.com/12c2e8db900a161718f25813b0efea317f10b484/power_manager/default_prefs/plugged_off_ms
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Nov 27 2017
The following revision refers to this bug: https://chromium.googlesource.com/chromium/src.git/+/f5f119ed7a6e864222797928bb2495d28326adc3 commit f5f119ed7a6e864222797928bb2495d28326adc3 Author: Todd Broch <tbroch@chromium.org> Date: Mon Nov 27 22:15:12 2017 power: decrease default idle off & suspend times. UMA data supports that active users typically react to either display dim or off cues quickly or are in fact idle and could move to lower power state. As such lets lower the times spent in each of these modes to hasten power savings which could be +20min of standby time or ~0.1% battery savings per idle transition. With change idle times are: BatteryScreenDimDelayMs = 300000 (5min no change) BatteryScreenOffDelayMs = 330000 (from 6 -> 5.5min) BatteryIdleDelayMs = 390000 (from 10 -> 6.5min) AcScreenDimDelayMs = 420000 (7min no change) AcScreenOffDelayMs = 450000 (from 8 -> 7.5min) AcIdleDelayMs = 1800000 (15min no change) correct times. BUG: 782725 TEST: manual, let device idle suspend & verify transistions occur at Change-Id: I7659f3e3bd684342fbd9a5bd2553d45a2970cf82 Reviewed-on: https://chromium-review.googlesource.com/777974 Reviewed-by: Dan Erat <derat@chromium.org> Commit-Queue: Dan Erat <derat@chromium.org> Cr-Commit-Position: refs/heads/master@{#519424} [modify] https://crrev.com/f5f119ed7a6e864222797928bb2495d28326adc3/chrome/browser/chromeos/power/power_prefs.cc
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Nov 29 2017
Change done although not yet available on ToT build until chrome uprevs. Summarizing change, unplugged_off_ms = 330000 (from 6 -> 5.5min) unplugged_suspend_ms = 390000 (from 10 -> 6.5min) plugged_off_ms = 450000 (from 8 -> 7.5min)
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Jan 22 2018
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Jan 23 2018
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Comment 1 by derat@chromium.org
, Nov 9 2017