Re: The 3G (or nG) Kernel Memory Space Offset

[Jan Engelhardt]

>> 
>> Sorry for my typo. I actually means "0-1G physical memory space." My
>> question is actually why there is a 3G offset from linear kernel to
>> physical kernel. Why not simply have kernel memory linear space
>> located on 0-1G linear address, and therefore the physical kernel and
>> linear kernel just coincide?
>
>the price for that would be that you would have to flush all the tlb's
>on each syscall. That's seen as a quite hefty price by many kernel
>developers.

Since it's all just virtual addresses, is the TLB flush really that much 
different when kernelspace runs from (virtual) 0x00000000-0x3FFFFFFF rather 
than (virtual)0xC000000-0xFFFFFFFF?


Jan Engelhardt
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