Messages in this thread | | | Date | Sun, 21 Mar 2004 18:15:13 +0100 | From | Manfred Spraul <> | Subject | Re: locking user space memory in kernel |
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Roland Dreier wrote:
> Manfred> I think just get_user_pages() should be sufficient: the > Manfred> pages won't be swapped out. You don't need to set > Manfred> VM_LOCKED in vma->vm_flags to prevent the swap out. In > Manfred> the worst case, the pte is cleared a that will cause a > Manfred> soft page fault, but the physical address won't > Manfred> change. Multiple get_user_pages() calls on overlapping > Manfred> regions are ok, the page count is an atomic_t, at least > Manfred> 24-bit large. > >There is one case that we ran into where the physical address can >change: if a process does a fork() and then triggers COW. > You are right. What should happen if there are registered transfers during fork()? Copy the pages during the fork() syscall?
-- Manfred
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