Messages in this thread | | | Date | Mon, 8 Jun 2009 16:11:56 +0100 | From | Matthew Garrett <> | Subject | Re: Run-time PM idea (was: Re: [linux-pm] [RFC][PATCH 0/2] PM: Rearrange core suspend code) |
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On Mon, Jun 08, 2009 at 05:06:03PM +0200, Ingo Molnar wrote:
> But if you think that tracking the usage state of the hardware is > 'complexity', then you very much dont know what you are talking > about. The main task of the kernel is to track hardware usage and to > abstract away the fact that the same hardware is used by multiple > tasks, and to do it safely. It's what the kernel does all day.
What I'm saying is that you don't *know* what the usage state of the hardware is, and in many cases you can't know. A given user may be happy to sacrifice their SATA hotplug support. Another with identical hardware may not. A given network application may be mission critical and intolerant of the network interface being shut down. The same application in a different context may not. We'd need to provide a bewildering array of interfaces to distinguish between these situations, and we'd be unable to turn on autosuspend until the entirity of userspace had been ported to them.
-- Matthew Garrett | mjg59@srcf.ucam.org
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