On Tue, 29 Jan 2002, Oliver Xymoron wrote:
>
> fork:
> detach page tables from parent
- leave the option ot just mark them read-only on architectures that
support it (ie x86, I think alpha does this too).
> retain pointer to "backing page tables" in parent and child
> update use count in page tables
You want to copy the top-level page table directory (with the "present
bit" disabled or something), not just retain a pointer to it. Otherwise
you just get really confused after two fork() calls, where you can have
multiple "backing page tables".
> "prefault" tables for current stack and instruction pages in both parent
> and child
Don't unconditionally prefault. There are many potentially useful things
that do _not_ want to do this, for example snapshot creation.
So the generic "do_fork()" thing should _not_ do prefaulting, although
"sys_fork()" may well choose to do it.
Linus
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This archive was generated by hypermail 2b29 : Thu Jan 31 2002 - 21:01:06 EST