Messages in this thread | | | Date | Fri, 03 Jul 2009 12:14:52 -0700 | From | "H. Peter Anvin" <> | Subject | Re: [Bug Fix]: Do 32-bit table calculations in pre-processor |
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Michael S. Zick wrote: >> >> The PGTABLE reservation seems much too big. I think 1 page should be >> sufficient for a system with large pages. Even if not, 0x6d000 is way >> too large. And they symptoms of failing to reserve the initial >> pagetable are pretty non-subtle. >> > > Random system halts, deadlocks with interrupts disabled? > Yup, that sounds familiar. > > If I ever get more than a stopped machine with a glowing power light; > I will be certain to share. >
Let's see... on a non-PSE system we may need one PDE and one PTE page per 4 MB, up to 1 GB, for a total of 256 pages or 1 MB of memory, so in that sense 0x6d000 (109 pages) doesn't sound at all unreasonable (non-PSE system with 512 MB of RAM?)
However, we shouldn't have to do this kind of hacks with MAPPING_BEYOND_END, and we *certainly* shouldn't do it by implicitly hard-coding the value of PAGE_SHIFT.
-hpa
-- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf.
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