Messages in this thread | | | Date | Thu, 07 Aug 2008 16:12:35 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [PATCH]Fix broken VMI in 2.6.27-rc.. |
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Linus Torvalds wrote: > > 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. >
Indeed. Unfortunately I don't see any other options.
-hpa
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