By accounting against the present PTEs, scanning speed reflects the
actual present (mapped) memory.
Suggested-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
include/linux/hugetlb.h | 8 ++++++--
include/linux/mm.h | 6 +++---
kernel/sched/fair.c | 37 +++++++++++++++++++++----------------
mm/hugetlb.c | 10 ++++++++--
mm/mprotect.c | 41 ++++++++++++++++++++++++++++++-----------
5 files changed, 68 insertions(+), 34 deletions(-)
Index: linux/include/linux/hugetlb.h
===================================================================
--- linux.orig/include/linux/hugetlb.h
+++ linux/include/linux/hugetlb.h
@@ -87,7 +87,7 @@ struct page *follow_huge_pud(struct mm_s
pud_t *pud, int write);
int pmd_huge(pmd_t pmd);
int pud_huge(pud_t pmd);
-void hugetlb_change_protection(struct vm_area_struct *vma,
+unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
unsigned long address, unsigned long end, pgprot_t newprot);
#else /* !CONFIG_HUGETLB_PAGE */
@@ -132,7 +132,11 @@ static inline void copy_huge_page(struct
{
}
-#define hugetlb_change_protection(vma, address, end, newprot)
+static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
+ unsigned long address, unsigned long end, pgprot_t newprot)
+{
+ return 0;
+}
static inline void __unmap_hugepage_range_final(struct mmu_gather *tlb,
struct vm_area_struct *vma, unsigned long start,
Index: linux/include/linux/mm.h
===================================================================
--- linux.orig/include/linux/mm.h
+++ linux/include/linux/mm.h
@@ -1099,7 +1099,7 @@ extern unsigned long move_page_tables(st
extern unsigned long do_mremap(unsigned long addr,
unsigned long old_len, unsigned long new_len,
unsigned long flags, unsigned long new_addr);
-extern void change_protection(struct vm_area_struct *vma, unsigned long start,
+extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgprot_t newprot,
int dirty_accountable);
extern int mprotect_fixup(struct vm_area_struct *vma,
@@ -1581,10 +1581,10 @@ static inline pgprot_t vma_prot_none(str
return pgprot_modify(vma->vm_page_prot, vm_get_page_prot(vmflags));
}
-static inline void
+static inline unsigned long
change_prot_none(struct vm_area_struct *vma, unsigned long start, unsigned long end)
{
- change_protection(vma, start, end, vma_prot_none(vma), 0);
+ return change_protection(vma, start, end, vma_prot_none(vma), 0);
}
struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
Index: linux/kernel/sched/fair.c
===================================================================
--- linux.orig/kernel/sched/fair.c
+++ linux/kernel/sched/fair.c
@@ -914,8 +914,8 @@ void task_numa_work(struct callback_head
struct task_struct *p = current;
struct mm_struct *mm = p->mm;
struct vm_area_struct *vma;
- unsigned long offset, end;
- long length;
+ unsigned long start, end;
+ long pages;
WARN_ON_ONCE(p != container_of(work, struct task_struct, numa_work));
@@ -942,30 +942,35 @@ void task_numa_work(struct callback_head
if (cmpxchg(&mm->numa_next_scan, migrate, next_scan) != migrate)
return;
- offset = mm->numa_scan_offset;
- length = sysctl_sched_numa_scan_size;
- length <<= 20;
+ start = mm->numa_scan_offset;
+ pages = sysctl_sched_numa_scan_size;
+ pages <<= 20 - PAGE_SHIFT; /* MB in pages */
+ if (!pages)
+ return;
down_write(&mm->mmap_sem);
- vma = find_vma(mm, offset);
+ vma = find_vma(mm, start);
if (!vma) {
ACCESS_ONCE(mm->numa_scan_seq)++;
- offset = 0;
+ start = 0;
vma = mm->mmap;
}
- for (; vma && length > 0; vma = vma->vm_next) {
+ for (; vma; vma = vma->vm_next) {
if (!vma_migratable(vma))
continue;
- offset = max(offset, vma->vm_start);
- end = min(ALIGN(offset + length, HPAGE_SIZE), vma->vm_end);
- length -= end - offset;
-
- change_prot_none(vma, offset, end);
-
- offset = end;
+ do {
+ start = max(start, vma->vm_start);
+ end = ALIGN(start + (pages << PAGE_SHIFT), HPAGE_SIZE);
+ end = min(end, vma->vm_end);
+ pages -= change_prot_none(vma, start, end);
+ start = end;
+ if (pages <= 0)
+ goto out;
+ } while (end != vma->vm_end);
}
- mm->numa_scan_offset = offset;
+out:
+ mm->numa_scan_offset = start;
up_write(&mm->mmap_sem);
}
Index: linux/mm/hugetlb.c
===================================================================
--- linux.orig/mm/hugetlb.c
+++ linux/mm/hugetlb.c
@@ -3014,7 +3014,7 @@ same_page:
return i ? i : -EFAULT;
}
-void hugetlb_change_protection(struct vm_area_struct *vma,
+unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
unsigned long address, unsigned long end, pgprot_t newprot)
{
struct mm_struct *mm = vma->vm_mm;
@@ -3022,6 +3022,7 @@ void hugetlb_change_protection(struct vm
pte_t *ptep;
pte_t pte;
struct hstate *h = hstate_vma(vma);
+ unsigned long pages = 0;
BUG_ON(address >= end);
flush_cache_range(vma, address, end);
@@ -3032,12 +3033,15 @@ void hugetlb_change_protection(struct vm
ptep = huge_pte_offset(mm, address);
if (!ptep)
continue;
- if (huge_pmd_unshare(mm, &address, ptep))
+ if (huge_pmd_unshare(mm, &address, ptep)) {
+ pages++;
continue;
+ }
if (!huge_pte_none(huge_ptep_get(ptep))) {
pte = huge_ptep_get_and_clear(mm, address, ptep);
pte = pte_mkhuge(pte_modify(pte, newprot));
set_huge_pte_at(mm, address, ptep, pte);
+ pages++;
}
}
spin_unlock(&mm->page_table_lock);
@@ -3049,6 +3053,8 @@ void hugetlb_change_protection(struct vm
*/
flush_tlb_range(vma, start, end);
mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
+
+ return pages << h->order;
}
int hugetlb_reserve_pages(struct inode *inode,
Index: linux/mm/mprotect.c
===================================================================
--- linux.orig/mm/mprotect.c
+++ linux/mm/mprotect.c
@@ -28,12 +28,13 @@
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
-static void change_pte_range(struct mm_struct *mm, pmd_t *pmd,
+static unsigned long change_pte_range(struct mm_struct *mm, pmd_t *pmd,
unsigned long addr, unsigned long end, pgprot_t newprot,
int dirty_accountable)
{
pte_t *pte, oldpte;
spinlock_t *ptl;
+ unsigned long pages = 0;
pte = pte_offset_map_lock(mm, pmd, addr, &ptl);
arch_enter_lazy_mmu_mode();
@@ -53,6 +54,7 @@ static void change_pte_range(struct mm_s
ptent = pte_mkwrite(ptent);
ptep_modify_prot_commit(mm, addr, pte, ptent);
+ pages++;
} else if (IS_ENABLED(CONFIG_MIGRATION) && !pte_file(oldpte)) {
swp_entry_t entry = pte_to_swp_entry(oldpte);
@@ -65,18 +67,22 @@ static void change_pte_range(struct mm_s
set_pte_at(mm, addr, pte,
swp_entry_to_pte(entry));
}
+ pages++;
}
} while (pte++, addr += PAGE_SIZE, addr != end);
arch_leave_lazy_mmu_mode();
pte_unmap_unlock(pte - 1, ptl);
+
+ return pages;
}
-static inline void change_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+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)
{
pmd_t *pmd;
unsigned long next;
+ unsigned long pages = 0;
pmd = pmd_offset(pud, addr);
do {
@@ -84,35 +90,42 @@ static inline void change_pmd_range(stru
if (pmd_trans_huge(*pmd)) {
if (next - addr != HPAGE_PMD_SIZE)
split_huge_page_pmd(vma->vm_mm, pmd);
- else if (change_huge_pmd(vma, pmd, addr, newprot))
+ else if (change_huge_pmd(vma, pmd, addr, newprot)) {
+ pages += HPAGE_PMD_NR;
continue;
+ }
/* fall through */
}
if (pmd_none_or_clear_bad(pmd))
continue;
- change_pte_range(vma->vm_mm, pmd, addr, next, newprot,
+ pages += change_pte_range(vma->vm_mm, pmd, addr, next, newprot,
dirty_accountable);
} while (pmd++, addr = next, addr != end);
+
+ return pages;
}
-static inline void change_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+static inline unsigned long change_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
unsigned long addr, unsigned long end, pgprot_t newprot,
int dirty_accountable)
{
pud_t *pud;
unsigned long next;
+ unsigned long pages = 0;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
- change_pmd_range(vma, pud, addr, next, newprot,
+ pages += change_pmd_range(vma, pud, addr, next, newprot,
dirty_accountable);
} while (pud++, addr = next, addr != end);
+
+ return pages;
}
-static void change_protection_range(struct vm_area_struct *vma,
+static unsigned long change_protection_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end, pgprot_t newprot,
int dirty_accountable)
{
@@ -120,6 +133,7 @@ static void change_protection_range(stru
pgd_t *pgd;
unsigned long next;
unsigned long start = addr;
+ unsigned long pages = 0;
BUG_ON(addr >= end);
pgd = pgd_offset(mm, addr);
@@ -128,24 +142,29 @@ static void change_protection_range(stru
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
- change_pud_range(vma, pgd, addr, next, newprot,
+ pages += change_pud_range(vma, pgd, addr, next, newprot,
dirty_accountable);
} while (pgd++, addr = next, addr != end);
flush_tlb_range(vma, start, end);
+
+ return pages;
}
-void change_protection(struct vm_area_struct *vma, unsigned long start,
+unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
unsigned long end, pgprot_t newprot,
int dirty_accountable)
{
struct mm_struct *mm = vma->vm_mm;
+ unsigned long pages;
mmu_notifier_invalidate_range_start(mm, start, end);
if (is_vm_hugetlb_page(vma))
- hugetlb_change_protection(vma, start, end, newprot);
+ pages = hugetlb_change_protection(vma, start, end, newprot);
else
- change_protection_range(vma, start, end, newprot, dirty_accountable);
+ pages = change_protection_range(vma, start, end, newprot, dirty_accountable);
mmu_notifier_invalidate_range_end(mm, start, end);
+
+ return pages;
}
int
--
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