Messages in this thread | | | Date | Fri, 9 May 2003 09:48:04 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] i386 uaccess to fixmap pages |
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On Fri, 9 May 2003, Dave Hansen wrote: > > We've been playing with patches in the -mjb tree which make PAGE_OFFSET > and TASK_SIZE move to some weird values. I have it to the point where I > could do a 3.875:0.125 user:kernel split.
That's still not "weird" in the current sense.
We've always (well, for a long time) been able to handle a TASK_SIZE that has a 111..00000 pattern - and in fact we used to _depend_ on that kind of pattern, because macros like "virt_to_phys()" were simple bitwise-and operations. There may be some code in the kernel that still depends on that kind of bitwise operation with TASK_SIZE.
Your 3.875:0.125 split still fits that pattern, and thus doesn't create any new cases.
In contrast, a TASK_SIZE of 0xc1000000 can no longer just "mask off" the kernel address bits. And _that_ is what I meant with "strange value".
Linus
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