Messages in this thread | | | Date | Fri, 30 Oct 2015 20:40:32 +0100 (CET) | From | Jiri Kosina <> | Subject | Re: [PATCH 0/3] PM, vfs: use filesystem freezing instead of kthread freezer |
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On Fri, 30 Oct 2015, Pavel Machek wrote:
> > I would say instead "no I/O is allowed from now on". Maybe that's an > > overstatement, but I think it comes closer to the truth.
But that's what PM callbacks are for.
> Exactly. And I'm pretty sure hardware drivers do use kernel threads, > and do I/O from them. > > LEDs are just one example
And why is that relevant? First, I don't see any freezable kthread in leds class implementation whatsoever. Second, I am pretty sure that it's quite unlikely to participate in filesystem I/O.
Sure, you need to suspend and resume the devices when going through suspend. That's why led_suspend() exists. How would try_to_freeze() help at all? That's basically just a fancy schedule() called at certain points.
-- Jiri Kosina SUSE Labs
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