Hello..
Well, i was wondering if kernel memory is swappable.
No, kernel memory always stays in RAM.
I was also referring to the window. I.e. via the identity mapping. I.e. I am
not sure that vmalloc only uses the last 128mb, i.e. 3.8 - 4gb virtual memory
addresses.
I never really confirms it other than just by doing a general code
observation. You could try doing vmalloc() and see what range of virtual
address you'll get.
Yes. I understood that each one is 4 bytes and you have about 1 million of
those that can be used at any one time by the MMU (i think).
I never count them, so on this part I really can't suggest anything.
The thing is, IIRC when i saw the description of MMU capabilities, i did some
calculations and the page tables the MMU can address at any one time are at
most 1gb.
This isn't about the maximum number of entries the TLB can hold, right?
All I know, MMU can address the whole 4GB address space... Care to
share how you did the calculation that yields the 1GB number? Maybe in
this case it is who don't realize how MMU really works.
If the kernel space is 1GB, what is left for the applications.
They will need to address their 0-3gb address space.
Even worse, is that from what i understand you are saying. Each application
should also have the kernel page tables of 1gb with it.
Nope, all the process refer to so called master kernel page directory
IIRC, so kernel page tables aren't duplicated across the processes.
I have a feeling i did not understand how many virtual pages the MMU can
address. Can anyone correct me/clarify?
Neither do I, I am still reading about it. So, if you can help us here
clarifying this issue, personally I welcome your help.
regards,
Mulyadi
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