Re: context overflow
From: Paul Mackerras <hidden>
Date: 2001-02-06 10:55:29
Dan Malek writes:
Heh :-)....Right, but it will require a context, and active_mm is the proper place to store/retrieve it. Doesn't the HIGHMEM option require we properly use a kernel context? Or, do we just get lucky there, too :-).
The way we do things on 6xx/7xx, kernel accesses to addresses >= 0xc0000000 don't depend on active_mm or on the currently selected context at all. We can effectively choose a different context for each 256MB segment of the address space, and we always choose context 0 for segments 0xc to 0xf. Further, the hash_page routine looks in swapper_pg_dir for linux PTEs for addresses >= 0xc0000000, rather than in the page tables associated with current->active_mm or current->mm. -- Paul Mackerras, Open Source Research Fellow, Linuxcare, Inc. +61 2 6262 8990 tel, +61 2 6262 8991 fax paulus@linuxcare.com.au, http://www.linuxcare.com.au/ Linuxcare. Putting Open Source to work. ** Sent via the linuxppc-dev mail list. See http://lists.linuxppc.org/