Re: virt_to_page for userspace pointers

From: Alan Cox
Date: Sun Feb 13 2011 - 17:01:50 EST


> > If you don't lock the page, you have no guarantee that it won't get
> > swapped out or migrated while you look at the physical page.
>
> That's fine, I know that if the page is there at all then it has been
> locked by a (different) kernel driver. Is there any way to find out what
> I want?

How do you know the other driver isn't in the middle of releasing the
page ? Doing that deep in mm code without locking inversions will be fun.

Alan
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