Messages in this thread | | | Date | Wed, 27 Nov 2013 12:56:34 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 0/3] Hook up powerclamp with PM QOS and cpuidle |
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On Tue, Nov 26, 2013 at 03:20:08PM -0800, Jacob Pan wrote: > This patchset is intended to address the behavior change and efficiency > loss introduced by using consolidated idle routine in powerclamp driver. > > Specifically, > [PATCH 3/8] idle, thermal, acpi: Remove home grown idle implementations > > The motivation is that after using common idle routine, powerclamp driver > can no longer pick the deepest idle state needed to conserve power. > Idle state is selected by governors which can be influenced by PM QOS and > other factors. This patchset hooks up powerclamp idle injection with PM > QOS and eventually influce idle governors to pick the power saving target > states. > > There are some downside of this approach. Due to overhead, communication > with PM QOS is at enable/disable idle injection time instead of each > injection period. The implication is that if the system natual idle is > more than target injected idle, powerclamp will skip some injection period. > During this period however, deepest idle state may still be chosen > necessarily regardless the latency constraint.
Does the QoS stuff have a means of notifying its users of constraints violation? I suspect some applications might light to be told if their requests aren't honoured.
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