Messages in this thread | | | Date | Wed, 29 Oct 2008 23:56:00 +0000 | From | Matthew Garrett <> | Subject | Re: [linux-pm] Freezer: Don't count threads waiting for frozen filesystems. |
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On Wed, Oct 29, 2008 at 04:37:30PM -0400, Alan Stern wrote:
> I discussed this last summer with Rafael. It's a lot harder than it > looks, for all sorts of reasons. For example, what about user tasks > that have access to memory-mapped I/O regions?
The only interesting cases of this I know of are X (which ought to stop doing so in the near future) and certain sound operations (which are going via a well-defined API anyway and need to handle devices going away at random, so not a problem). There may be some other niche cases, but really - if you're mmapping hardware then it's generally because you haven't written a proper kernel driver. Do that instead. Runtime power management's already going to make you wildly unhappy.
-- Matthew Garrett | mjg59@srcf.ucam.org
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