Re: [Hdaps-devel] Generic interface for accelerometers (AMS, HDAPS, ...)

[Thomas Tuttle <thinkinginbinary+lkml@gmail.com>]

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On July 04 at 06:26 EDT, Shem Multinymous hastily scribbled:
> Will moving the hdapsd userspace daemon from sysfs polling to the
> input infrastructure cause a noticable latency increase compared to
> polling sysfs? This functionality is highly time-critical.
>
> Also, there's a small issue with polling frequency. hdapsd needs a
> fairly high frequency (say, 50Hz) to gather statistics and keep
> response latency low, whereas the hdaps driver's internal polling
> (routing to the input infrastructure) is currently done at only 20Hz.
> We'll need to increase the latter, thereby slightly increasing system
> load when hdaps isn't running.

Just out of curiousity, is there any reason that these hard drive
parking schemes *aren't* implemented entirely in the kernel?  Wouldn't
implementing it in the kernel give it much lower latency?

-- 
Thomas Tuttle (thinkinginbinary@gmail.com)
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