mm: numa: Do not batch handle PMD pages

[~andy/linux] / mm / mprotect.c

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 9a74855f1241090b056491657cdcdd330f83a255..a0302ac0be985393256a99070becec949f92ae46 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -37,15 +37,12 @@ static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
 
 static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
                unsigned long addr, unsigned long end, pgprot_t newprot,
-               int dirty_accountable, int prot_numa, bool *ret_all_same_cpupid)
+               int dirty_accountable, int prot_numa)
 {
        struct mm_struct *mm = vma->vm_mm;
        pte_t *pte, oldpte;
        spinlock_t *ptl;
        unsigned long pages = 0;
-       bool all_same_cpupid = true;
-       int last_cpu = -1;
-       int last_pid = -1;
 
        pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
        arch_enter_lazy_mmu_mode();
@@ -64,19 +61,6 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 
                                page = vm_normal_page(vma, addr, oldpte);
                                if (page) {
-                                       int cpupid = page_cpupid_last(page);
-                                       int this_cpu = cpupid_to_cpu(cpupid);
-                                       int this_pid = cpupid_to_pid(cpupid);
-
-                                       if (last_cpu == -1)
-                                               last_cpu = this_cpu;
-                                       if (last_pid == -1)
-                                               last_pid = this_pid;
-                                       if (last_cpu != this_cpu ||
-                                           last_pid != this_pid) {
-                                               all_same_cpupid = false;
-                                       }
-
                                        if (!pte_numa(oldpte)) {
                                                ptent = pte_mknuma(ptent);
                                                updated = true;
@@ -115,26 +99,9 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
        arch_leave_lazy_mmu_mode();
        pte_unmap_unlock(pte - 1, ptl);
 
-       *ret_all_same_cpupid = all_same_cpupid;
        return pages;
 }
 
-#ifdef CONFIG_NUMA_BALANCING
-static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr,
-                                      pmd_t *pmd)
-{
-       spin_lock(&mm->page_table_lock);
-       set_pmd_at(mm, addr & PMD_MASK, pmd, pmd_mknuma(*pmd));
-       spin_unlock(&mm->page_table_lock);
-}
-#else
-static inline void change_pmd_protnuma(struct mm_struct *mm, unsigned long addr,
-                                      pmd_t *pmd)
-{
-       BUG();
-}
-#endif /* CONFIG_NUMA_BALANCING */
-
 static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
                pud_t *pud, unsigned long addr, unsigned long end,
                pgprot_t newprot, int dirty_accountable, int prot_numa)
@@ -142,7 +109,6 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
        pmd_t *pmd;
        unsigned long next;
        unsigned long pages = 0;
-       bool all_same_cpupid;
 
        pmd = pmd_offset(pud, addr);
        do {
@@ -168,17 +134,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
                if (pmd_none_or_clear_bad(pmd))
                        continue;
                this_pages = change_pte_range(vma, pmd, addr, next, newprot,
-                                dirty_accountable, prot_numa, &all_same_cpupid);
+                                dirty_accountable, prot_numa);
                pages += this_pages;
-
-               /*
-                * If we are changing protections for NUMA hinting faults then
-                * set pmd_numa if the examined pages were all on the same
-                * node. This allows a regular PMD to be handled as one fault
-                * and effectively batches the taking of the PTL
-                */
-               if (prot_numa && this_pages && all_same_cpupid)
-                       change_pmd_protnuma(vma->vm_mm, addr, pmd);
        } while (pmd++, addr = next, addr != end);
 
        return pages;