Messages in this thread Patch in this message | | | Date | Tue, 8 Aug 2017 05:12:20 -0700 | From | Matthew Wilcox <> | Subject | Re: [PATCH -mm] mm: Clear to access sub-page last when clearing huge page |
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On Mon, Aug 07, 2017 at 03:21:31PM +0800, Huang, Ying wrote: > @@ -2509,7 +2509,8 @@ enum mf_action_page_type { > #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS) > extern void clear_huge_page(struct page *page, > unsigned long addr, > - unsigned int pages_per_huge_page); > + unsigned int pages_per_huge_page, > + unsigned long addr_hint);
I don't really like adding the extra argument to this function ...
> +++ b/mm/huge_memory.c > @@ -549,7 +549,8 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, > struct vm_area_struct *vma = vmf->vma; > struct mem_cgroup *memcg; > pgtable_t pgtable; > - unsigned long haddr = vmf->address & HPAGE_PMD_MASK; > + unsigned long address = vmf->address; > + unsigned long haddr = address & HPAGE_PMD_MASK; > > VM_BUG_ON_PAGE(!PageCompound(page), page); > > @@ -566,7 +567,7 @@ static int __do_huge_pmd_anonymous_page(struct vm_fault *vmf, struct page *page, > return VM_FAULT_OOM; > } > > - clear_huge_page(page, haddr, HPAGE_PMD_NR); > + clear_huge_page(page, haddr, HPAGE_PMD_NR, address); > /* > * The memory barrier inside __SetPageUptodate makes sure that > * clear_huge_page writes become visible before the set_pmd_at()
How about calling:
- clear_huge_page(page, haddr, HPAGE_PMD_NR); + clear_huge_page(page, address, HPAGE_PMD_NR);
> +++ b/mm/memory.c > @@ -4363,10 +4363,10 @@ static void clear_gigantic_page(struct page *page, > clear_user_highpage(p, addr + i * PAGE_SIZE); > } > } > -void clear_huge_page(struct page *page, > - unsigned long addr, unsigned int pages_per_huge_page) > +void clear_huge_page(struct page *page, unsigned long addr, > + unsigned int pages_per_huge_page, unsigned long addr_hint) > { > - int i; > + int i, n, base, l; > > if (unlikely(pages_per_huge_page > MAX_ORDER_NR_PAGES)) { > clear_gigantic_page(page, addr, pages_per_huge_page);
... and doing this:
void clear_huge_page(struct page *page, - unsigned long addr, unsigned int pages_per_huge_page) + unsigned long addr_hint, unsigned int pages_per_huge_page) { - int i; + int i, n, base, l; + unsigned long addr = addr_hint & + (1UL << (pages_per_huge_page + PAGE_SHIFT));
> @@ -4374,9 +4374,31 @@ void clear_huge_page(struct page *page, > } > > might_sleep(); > - for (i = 0; i < pages_per_huge_page; i++) { > + VM_BUG_ON(clamp(addr_hint, addr, addr + > + (pages_per_huge_page << PAGE_SHIFT)) != addr_hint);
... then you can ditch this check
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