diff options
Diffstat (limited to 'mm/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 19 |
1 files changed, 16 insertions, 3 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index d4928769..de8d5cf 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1458,6 +1458,12 @@ out: return ret; } +/* + * Returns + * - 0 if PMD could not be locked + * - 1 if PMD was locked but protections unchange and TLB flush unnecessary + * - 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, int prot_numa) { @@ -1466,9 +1472,11 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, if (__pmd_trans_huge_lock(pmd, vma) == 1) { pmd_t entry; - entry = pmdp_get_and_clear(mm, addr, pmd); + ret = 1; if (!prot_numa) { + entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_modify(entry, newprot); + ret = HPAGE_PMD_NR; BUG_ON(pmd_write(entry)); } else { struct page *page = pmd_page(*pmd); @@ -1476,12 +1484,17 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t *pmd, /* only check non-shared pages */ if (page_mapcount(page) == 1 && !pmd_numa(*pmd)) { + entry = pmdp_get_and_clear(mm, addr, pmd); entry = pmd_mknuma(entry); + ret = HPAGE_PMD_NR; } } - set_pmd_at(mm, addr, pmd, entry); + + /* Set PMD if cleared earlier */ + if (ret == HPAGE_PMD_NR) + set_pmd_at(mm, addr, pmd, entry); + spin_unlock(&vma->vm_mm->page_table_lock); - ret = 1; } return ret; |
