RE: how has set_pgdir been replaced in 2.4.x

["Martin Frey" <frey@scs.ch>]

Hi,

>> I noticed that in the 2.4.x Linux kernel the function 
>set_pgdir() has gone (at least for most platforms). When 
>looking at code that modifies kernel page tables (e.g.
>> vmalloc_area_pages) I could not figure out, how the page 
>global directories are kept consistent. It looks to me as if
>> global page directory entries were modified in one global 
>page directory (the swapper_pg_dir) only. If this is the case, 
>I wonder how the modifications are 'propagated'
>> into all the other global page directories
>
>They are now faulted on demand for vmalloc.  The cost of manually
>updating all the pgds for every vmalloc is just too expensive if
>you've got tens of thousands of threads in the system.
>

Is there an implication on drivers, e.g. not accessing vmalloc'd
memory from within a page fault handler? A page fault from a
page fault handler is quite ugly...

Best regards, Martin
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