Messages in this thread | | | Date | Thu, 7 Aug 2008 16:08:22 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH]Fix broken VMI in 2.6.27-rc.. |
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On Thu, 7 Aug 2008, H. Peter Anvin wrote: > > Just moving it down by 4 MB doesn't help, since the VMI guys want as much as > 64 MB, which is half the standard vmalloc area and hence too much address > space lost. We can't put it at the bottom of the vmalloc area, since that > boundary is not fixed, either.
Yeah, ok. Since this is a 32-bit only issue, 64MB is actually a fair chunk of our already limited virtual space.
> The one remaining fixed boundary in the machine is the kernel-userspace > boundary. Hence moving the 1:1 area up by one PDE unit and sticking the > fixmap area in that region.
Yeah, ok, but I'd be more nervous about the validation issues there. There might be a lot of code that assumes that TASK_SIZE is the start of the 1:1 area. It does sound like a good approach, it just makes me worry about the test coverage.
Linus
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