Messages in this thread | | | From | "Rafael J. Wysocki" <> | Subject | Re: [RFC PATCH V3 0/3] PM/CPU: Parallel enalbing nonboot cpus with resume devices | Date | Thu, 09 Oct 2014 00:01:07 +0200 |
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On Wednesday, October 08, 2014 10:54:41 PM Peter Zijlstra wrote: > On Thu, Sep 25, 2014 at 04:32:02PM +0800, Lan Tianyu wrote: > > This patchset is to parallel enabling nonboot cpus with resuming devices > > during system resume in order to accelerate S2RAM. From test result on > > a 8 logical core Haswell machine, system resume time reduces from 347ms > > to 217ms with this patchset. > > > > In the current world, all nonboot cpus are enabled serially during system > > resume. System resume sequence is that boot cpu enables nonboot cpu one by > > one and then resume devices. Before resuming devices, there are few tasks > > assigned to nonboot cpus after they are brought up. This wastes cpu usage. > > > > This patchset is to allow boot cpu to go forward to resume devices after > > bringing up one nonboot cpu and starting a thread. The thread will be in > > charge of bringing up other frozen cpus. The thread will be scheduled to > > the first online cpu to run . This makes enabling cpu2~x parallel with > > resuming devices. > > So I feel we should really clean up hotplug before doing anything like > this. Its a trainwreck and just piling more and more hacks ontop isn't > going to help any.
Agreed.
-- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.
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