Re: Hugetlbpages in very large memory machines.......
From: Hirokazu Takahashi
Date: Mon Mar 15 2004 - 21:36:14 EST
Hello,
> > + pte = huge_pte_alloc(mm, address);
> > + set_huge_pte(mm, vma, page, pte, vma->vm_flags & VM_WRITE);
>
> This looks broken. Another CPU could have raced to the same fault
> and already added an PTE here. You have to handle that.
>
> (my i386 version originally had the same problem)
Yes, you are true.
In the fault handler, we should use find_lock_page() instead of
find_get_page() to find a hugepage associated with the fault address.
After that pte_none(*pte) should be called again to check whether
some races has happened.
> > +/* update_mmu_cache(vma, address, *pte); */
>
> I have not studied low level IA64 VM in detail, but don't you need
> some kind of TLB flush here?
>
> -Andi
Thank you,
Hirokazu Takahashi.
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