diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/huge_memory.c | 13 | ||||
| -rw-r--r-- | mm/memory.c | 1 | ||||
| -rw-r--r-- | mm/mprotect.c | 14 |
3 files changed, 25 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cb9b3e847dac..8e791a3db6b6 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1471,7 +1471,7 @@ out: * - HPAGE_PMD_NR is protections changed and TLB flush necessary */ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, - unsigned long addr, pgprot_t newprot) + unsigned long addr, pgprot_t newprot, int prot_numa) { struct mm_struct *mm = vma->vm_mm; spinlock_t *ptl; @@ -1479,6 +1479,17 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) { pmd_t entry; + + /* + * Avoid trapping faults against the zero page. The read-only + * data is likely to be read-cached on the local CPU and + * local/remote hits to the zero page are not interesting. + */ + if (prot_numa && is_huge_zero_pmd(*pmd)) { + spin_unlock(ptl); + return 0; + } + ret = 1; entry = pmdp_get_and_clear_notify(mm, addr, pmd); entry = pmd_modify(entry, newprot); diff --git a/mm/memory.c b/mm/memory.c index d7921760cf79..bf244f56b05a 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3040,7 +3040,6 @@ static int do_numa_page(struct mm_struct *mm, struct vm_area_struct *vma, pte_unmap_unlock(ptep, ptl); return 0; } - BUG_ON(is_zero_pfn(page_to_pfn(page))); /* * Avoid grouping on DSO/COW pages in specific and RO pages diff --git a/mm/mprotect.c b/mm/mprotect.c index 76824d73380d..dd599fc235c2 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -76,6 +76,18 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd, if (pte_present(oldpte)) { pte_t ptent; + /* + * Avoid trapping faults against the zero or KSM + * pages. See similar comment in change_huge_pmd. + */ + if (prot_numa) { + struct page *page; + + page = vm_normal_page(vma, addr, oldpte); + if (!page || PageKsm(page)) + continue; + } + ptent = ptep_modify_prot_start(mm, addr, pte); ptent = pte_modify(ptent, newprot); @@ -142,7 +154,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma, split_huge_page_pmd(vma, addr, pmd); else { int nr_ptes = change_huge_pmd(vma, pmd, addr, - newprot); + newprot, prot_numa); if (nr_ptes) { if (nr_ptes == HPAGE_PMD_NR) { |