Messages in this thread | | | Date | Sat, 16 Feb 2008 11:22:18 -0800 (PST) | From | Christoph Lameter <> | Subject | Re: [patch 3/6] mmu_notifier: invalidate_page callbacks |
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On Fri, 15 Feb 2008, Andrew Morton wrote:
> > @@ -287,7 +288,8 @@ static int page_referenced_one(struct pa > > if (vma->vm_flags & VM_LOCKED) { > > referenced++; > > *mapcount = 1; /* break early from loop */ > > - } else if (ptep_clear_flush_young(vma, address, pte)) > > + } else if (ptep_clear_flush_young(vma, address, pte) | > > + mmu_notifier_age_page(mm, address)) > > referenced++; > > The "|" is obviously deliberate. But no explanation is provided telling us > why we still call the callback if ptep_clear_flush_young() said the page > was recently referenced. People who read your code will want to understand > this.
Andrea?
> > flush_cache_page(vma, address, pte_pfn(*pte)); > > entry = ptep_clear_flush(vma, address, pte); > > + mmu_notifier(invalidate_page, mm, address); > > I just don't see how ths can be done if the callee has another thread in > the middle of establishing IO against this region of memory. > ->invalidate_page() _has_ to be able to block. Confused.
The page lock is held and that holds off I/O?
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