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    SubjectRe: Async resume patch (was: Re: [GIT PULL] PM updates for 2.6.33)
    Hi!

    > > That's partly why I realy did suggest that we do the async stuff purely in
    > > the USB layer, rather than try to put it deeper in the device layer. And
    > > if we do support it "natively" in the device layer like Rafael's latest
    > > patch, I still think we should be very very nervous about making devices
    > > async unless there is a measured - and very noticeable - advantage.
    >
    > Agreed. Arjan's measurements indicated that USB was one of the biggest
    > offenders; everything else other than the PS/2 mouse was much faster.
    > Given these results there isn't much incentive to do anything else
    > asynchronously.
    >
    > (However other devices not present on Arjan's machine may be a
    > different story. Spinning up multiple external disks is a good example
    > -- although here it may be necessary for the driver to take charge,
    > because spinning up a disk requires a lot of power and doing too many
    > of them at the same time could be bad.)

    Well, system would better be able to supply enough current... because
    usb disks auto-sleep on their own, and then something like async ls -l
    /*/* would kill your machine...
    Pavel
    --
    (english) http://www.livejournal.com/~pavelmachek
    (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html


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