Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1574351

Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range()

From "Hillf Danton" <hillf.zj@alibaba-inc.com>
Newsgroups linux.kernel
Subject Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range()
Date 2017-02-06 05:10 +0100
Message-ID <t7IMN-8iP-5@gated-at.bofh.it> (permalink)
References <t7xHH-1ay-5@gated-at.bofh.it> <t7xHI-1ay-31@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On February 06, 2017 12:13 AM Zi Yan wrote: 
> 
> @@ -1233,33 +1233,31 @@ static inline unsigned long zap_pmd_range(struct mmu_gather *tlb,
>  				struct zap_details *details)
>  {
>  	pmd_t *pmd;
> +	spinlock_t *ptl;
>  	unsigned long next;
> 
>  	pmd = pmd_offset(pud, addr);
> +	ptl = pmd_lock(vma->vm_mm, pmd);
>  	do {
>  		next = pmd_addr_end(addr, end);
>  		if (pmd_trans_huge(*pmd) || pmd_devmap(*pmd)) {
>  			if (next - addr != HPAGE_PMD_SIZE) {
>  				VM_BUG_ON_VMA(vma_is_anonymous(vma) &&
>  				    !rwsem_is_locked(&tlb->mm->mmap_sem), vma);
> -				__split_huge_pmd(vma, pmd, addr, false, NULL);
> -			} else if (zap_huge_pmd(tlb, vma, pmd, addr))
> -				goto next;
> +				__split_huge_pmd_locked(vma, pmd, addr, false);
> +			} else if (__zap_huge_pmd_locked(tlb, vma, pmd, addr))
> +				continue;
>  			/* fall through */
>  		}
> -		/*
> -		 * Here there can be other concurrent MADV_DONTNEED or
> -		 * trans huge page faults running, and if the pmd is
> -		 * none or trans huge it can change under us. This is
> -		 * because MADV_DONTNEED holds the mmap_sem in read
> -		 * mode.
> -		 */
> -		if (pmd_none_or_trans_huge_or_clear_bad(pmd))
> -			goto next;
> +
> +		if (pmd_none_or_clear_bad(pmd))
> +			continue;
> +		spin_unlock(ptl);
>  		next = zap_pte_range(tlb, vma, pmd, addr, next, details);
> -next:
>  		cond_resched();
> +		spin_lock(ptl);
>  	} while (pmd++, addr = next, addr != end);

spin_lock() is appointed to the bench of pmd_lock().

> +	spin_unlock(ptl);
> 
>  	return addr;
>  }

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

[PATCH v3 00/14] mm: page migration enhancement for thp Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
  [PATCH v3 11/14] mm: hwpoison: soft offline supports thp migration Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
  [PATCH v3 13/14] mm: migrate: move_pages() supports thp migration Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
    Re: [PATCH v3 13/14] mm: migrate: move_pages() supports thp  migration Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-09 10:30 +0100
      Re: [PATCH v3 13/14] mm: migrate: move_pages() supports thp migration "Zi Yan" <zi.yan@sent.com> - 2017-02-09 18:40 +0100
  [PATCH v3 04/14] mm: x86: move _PAGE_SWP_SOFT_DIRTY from bit 7 to bit 1 Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
    Re: [PATCH v3 04/14] mm: x86: move _PAGE_SWP_SOFT_DIRTY from bit 7  to bit 1 Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-09 10:30 +0100
  [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range() Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
    Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range() "Hillf Danton" <hillf.zj@alibaba-inc.com> - 2017-02-06 05:10 +0100
    Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-06 08:50 +0100
      Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Zi Yan" <zi.yan@sent.com> - 2017-02-06 14:10 +0100
        Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-07 00:30 +0100
    Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-06 17:10 +0100
      Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Zi Yan" <zi.yan@sent.com> - 2017-02-06 17:40 +0100
        Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-06 18:40 +0100
      Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in zap_pmd_range() "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-02-07 15:00 +0100
    Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-07 15:30 +0100
      Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-07 17:40 +0100
        Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-07 19:00 +0100
          Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() "Kirill A. Shutemov" <kirill@shutemov.name> - 2017-02-13 12:00 +0100
            Re: [PATCH v3 03/14] mm: use pmd lock instead of racy checks in  zap_pmd_range() Andrea Arcangeli <aarcange@redhat.com> - 2017-02-13 15:50 +0100
  [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible. Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
    Re: [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible. Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-06 07:30 +0100
      Re: [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible. "Zi Yan" <zi.yan@sent.com> - 2017-02-06 13:20 +0100
    Re: [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible. Matthew Wilcox <willy@infradead.org> - 2017-02-06 16:10 +0100
      Re: [PATCH v3 01/14] mm: thp: make __split_huge_pmd_locked visible. "Zi Yan" <zi.yan@sent.com> - 2017-02-06 16:10 +0100
  [PATCH v3 09/14] mm: thp: check pmd migration entry in common path Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
    Re: [PATCH v3 09/14] mm: thp: check pmd migration entry in common  path Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> - 2017-02-09 10:30 +0100
  [PATCH v3 07/14] mm: thp: introduce CONFIG_ARCH_ENABLE_THP_MIGRATION Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
  [PATCH v3 05/14] mm: mempolicy: add queue_pages_node_check() Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
  [PATCH v3 14/14] mm: memory_hotplug: memory hotremove supports thp migration Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100
  [PATCH v3 02/14] mm: thp: create new __zap_huge_pmd_locked function. Zi Yan <zi.yan@sent.com> - 2017-02-05 17:20 +0100

csiph-web