Messages in this thread | | | Date | Thu, 1 Oct 2015 00:02:38 +0200 (CEST) | From | Thomas Gleixner <> | Subject | Re: [PATCH v7 07/11] arch/x86: enable task isolation functionality |
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On Wed, 30 Sep 2015, Chris Metcalf wrote: > So for now, if a task-isolation thread sets up a timer, > they're screwed: so, don't do that. And it's really not part of > the typical programming model for these kinds of userspace > drivers anyway, so it's pretty reasonable to forbid it.
There is a difference between forbidding it and looping for 10 minutes in the kernel.
I have yet to understand WHY this loop is there at all. All I've seen so far is that things might need to settle and that the indicator for settlement is that the next expiry time of the per cpu timer is set to KTIME_MAX.
To be blunt, that just stinks. This is duct tape engineering and not even close to a reasonable design.
Thanks,
tglx
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