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author | Olof Johansson <olof@lixom.net> | 2012-09-05 15:35:48 -0700 |
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committer | Olof Johansson <olof@lixom.net> | 2012-09-05 15:35:48 -0700 |
commit | 1875962377574b4edb7b164001e3e341c25290d5 (patch) | |
tree | 374a5299403ec21e2d9a66a6548ce876a388b589 /arch/x86/mm/hugetlbpage.c | |
parent | 5cbee140a28c2746449ae31e85738043ae4da927 (diff) | |
parent | c88a79a7789b2909ad1cf69ea2c9142030bbd6f4 (diff) | |
download | op-kernel-dev-1875962377574b4edb7b164001e3e341c25290d5.zip op-kernel-dev-1875962377574b4edb7b164001e3e341c25290d5.tar.gz |
Merge branch 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas into next/dt
* 'soc-core' of git://git.kernel.org/pub/scm/linux/kernel/git/horms/renesas:
ARM: mach-shmobile: Add compilation support for dtbs using 'make dtbs'
+ sync to 3.6-rc3
Diffstat (limited to 'arch/x86/mm/hugetlbpage.c')
-rw-r--r-- | arch/x86/mm/hugetlbpage.c | 21 |
1 files changed, 16 insertions, 5 deletions
diff --git a/arch/x86/mm/hugetlbpage.c b/arch/x86/mm/hugetlbpage.c index f6679a7..b91e485 100644 --- a/arch/x86/mm/hugetlbpage.c +++ b/arch/x86/mm/hugetlbpage.c @@ -56,9 +56,16 @@ static int vma_shareable(struct vm_area_struct *vma, unsigned long addr) } /* - * search for a shareable pmd page for hugetlb. + * Search for a shareable pmd page for hugetlb. In any case calls pmd_alloc() + * and returns the corresponding pte. While this is not necessary for the + * !shared pmd case because we can allocate the pmd later as well, it makes the + * code much cleaner. pmd allocation is essential for the shared case because + * pud has to be populated inside the same i_mmap_mutex section - otherwise + * racing tasks could either miss the sharing (see huge_pte_offset) or select a + * bad pmd for sharing. */ -static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) +static pte_t * +huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) { struct vm_area_struct *vma = find_vma(mm, addr); struct address_space *mapping = vma->vm_file->f_mapping; @@ -68,9 +75,10 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) struct vm_area_struct *svma; unsigned long saddr; pte_t *spte = NULL; + pte_t *pte; if (!vma_shareable(vma, addr)) - return; + return (pte_t *)pmd_alloc(mm, pud, addr); mutex_lock(&mapping->i_mmap_mutex); vma_prio_tree_foreach(svma, &iter, &mapping->i_mmap, idx, idx) { @@ -97,7 +105,9 @@ static void huge_pmd_share(struct mm_struct *mm, unsigned long addr, pud_t *pud) put_page(virt_to_page(spte)); spin_unlock(&mm->page_table_lock); out: + pte = (pte_t *)pmd_alloc(mm, pud, addr); mutex_unlock(&mapping->i_mmap_mutex); + return pte; } /* @@ -142,8 +152,9 @@ pte_t *huge_pte_alloc(struct mm_struct *mm, } else { BUG_ON(sz != PMD_SIZE); if (pud_none(*pud)) - huge_pmd_share(mm, addr, pud); - pte = (pte_t *) pmd_alloc(mm, pud, addr); + pte = huge_pmd_share(mm, addr, pud); + else + pte = (pte_t *)pmd_alloc(mm, pud, addr); } } BUG_ON(pte && !pte_none(*pte) && !pte_huge(*pte)); |