Subject: + clear_refs-redefine-callback-functions-for-page-table-walker.patch added to -mm tree
To: n-horiguchi@xxxxxxxxxxxxx,aneesh.kumar@xxxxxxxxxxxxxxxxxx,benh@xxxxxxxxxxxxxxxxxxx,cpw@xxxxxxx,hannes@xxxxxxxxxxx,kamezawa.hiroyu@xxxxxxxxxxxxxx,kirill.shutemov@xxxxxxxxxxxxxxx,kosaki.motohiro@xxxxxxxxxxxxxx,mhocko@xxxxxxx,mpm@xxxxxxxxxxx,riel@xxxxxxxxxx,xemul@xxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Mon, 10 Feb 2014 14:42:14 -0800
The patch titled
Subject: clear_refs: redefine callback functions for page table walker
has been added to the -mm tree. Its filename is
clear_refs-redefine-callback-functions-for-page-table-walker.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/clear_refs-redefine-callback-functions-for-page-table-walker.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/clear_refs-redefine-callback-functions-for-page-table-walker.patch
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------------------------------------------------------
From: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Subject: clear_refs: redefine callback functions for page table walker
Currently clear_refs_pte_range() is connected to pmd_entry() to split thps
if found. But now this work can be done in core page table walker code.
So we have no reason to keep this callback on pmd_entry(). This patch
moves pte handling code on pte_entry() callback.
clear_refs_write() has some prechecks about if we really walk over a given
vma. It's fine to let them done by test_walk() callback, so let's define
it.
Signed-off-by: Naoya Horiguchi <n-horiguchi@xxxxxxxxxxxxx>
Cc: Matt Mackall <mpm@xxxxxxxxxxx>
Cc: Cliff Wickman <cpw@xxxxxxx>
Cc: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxx>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Cc: Rik van Riel <riel@xxxxxxxxxx>
Cc: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
Cc: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/proc/task_mmu.c | 84 +++++++++++++++++--------------------------
1 file changed, 34 insertions(+), 50 deletions(-)
diff -puN fs/proc/task_mmu.c~clear_refs-redefine-callback-functions-for-page-table-walker fs/proc/task_mmu.c
--- a/fs/proc/task_mmu.c~clear_refs-redefine-callback-functions-for-page-table-walker
+++ a/fs/proc/task_mmu.c
@@ -698,7 +698,6 @@ enum clear_refs_types {
};
struct clear_refs_private {
- struct vm_area_struct *vma;
enum clear_refs_types type;
};
@@ -730,41 +729,43 @@ static inline void clear_soft_dirty(stru
#endif
}
-static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
+static int clear_refs_pte(pte_t *pte, unsigned long addr,
unsigned long end, struct mm_walk *walk)
{
struct clear_refs_private *cp = walk->private;
- struct vm_area_struct *vma = cp->vma;
- pte_t *pte, ptent;
- spinlock_t *ptl;
+ struct vm_area_struct *vma = walk->vma;
struct page *page;
- split_huge_page_pmd(vma, addr, pmd);
- if (pmd_trans_unstable(pmd))
+ if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
+ clear_soft_dirty(vma, addr, pte);
return 0;
-
- pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
- for (; addr != end; pte++, addr += PAGE_SIZE) {
- ptent = *pte;
-
- if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
- clear_soft_dirty(vma, addr, pte);
- continue;
- }
-
- if (!pte_present(ptent))
- continue;
-
- page = vm_normal_page(vma, addr, ptent);
- if (!page)
- continue;
-
- /* Clear accessed and referenced bits. */
- ptep_test_and_clear_young(vma, addr, pte);
- ClearPageReferenced(page);
}
- pte_unmap_unlock(pte - 1, ptl);
- cond_resched();
+ if (!pte_present(*pte))
+ return 0;
+ page = vm_normal_page(vma, addr, *pte);
+ if (!page)
+ return 0;
+ /* Clear accessed and referenced bits. */
+ ptep_test_and_clear_young(vma, addr, pte);
+ ClearPageReferenced(page);
+ return 0;
+}
+
+static int clear_refs_test_walk(unsigned long start, unsigned long end,
+ struct mm_walk *walk)
+{
+ struct clear_refs_private *cp = walk->private;
+ struct vm_area_struct *vma = walk->vma;
+
+ /*
+ * Writing 1 to /proc/pid/clear_refs affects all pages.
+ * Writing 2 to /proc/pid/clear_refs only affects anonymous pages.
+ * Writing 3 to /proc/pid/clear_refs only affects file mapped pages.
+ */
+ if (cp->type == CLEAR_REFS_ANON && vma->vm_file)
+ walk->skip = 1;
+ if (cp->type == CLEAR_REFS_MAPPED && !vma->vm_file)
+ walk->skip = 1;
return 0;
}
@@ -806,33 +807,16 @@ static ssize_t clear_refs_write(struct f
.type = type,
};
struct mm_walk clear_refs_walk = {
- .pmd_entry = clear_refs_pte_range,
+ .pte_entry = clear_refs_pte,
+ .test_walk = clear_refs_test_walk,
.mm = mm,
.private = &cp,
};
down_read(&mm->mmap_sem);
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_start(mm, 0, -1);
- for (vma = mm->mmap; vma; vma = vma->vm_next) {
- cp.vma = vma;
- if (is_vm_hugetlb_page(vma))
- continue;
- /*
- * Writing 1 to /proc/pid/clear_refs affects all pages.
- *
- * Writing 2 to /proc/pid/clear_refs only affects
- * Anonymous pages.
- *
- * Writing 3 to /proc/pid/clear_refs only affects file
- * mapped pages.
- */
- if (type == CLEAR_REFS_ANON && vma->vm_file)
- continue;
- if (type == CLEAR_REFS_MAPPED && !vma->vm_file)
- continue;
- walk_page_range(vma->vm_start, vma->vm_end,
- &clear_refs_walk);
- }
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ walk_page_vma(vma, &clear_refs_walk);
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_end(mm, 0, -1);
flush_tlb_mm(mm);
_
Patches currently in -mm which might be from n-horiguchi@xxxxxxxxxxxxx are
mm-memory-failurec-move-refcount-only-in-mf_count_increased.patch
mm-hugetlb-unify-region-structure-handling.patch
mm-hugetlb-improve-cleanup-resv_map-parameters.patch
mm-hugetlb-fix-race-in-region-tracking.patch
mm-hugetlb-remove-resv_map_put.patch
mm-hugetlb-use-vma_resv_map-map-types.patch
mm-hugetlb-improve-page-fault-scalability.patch
mm-hugetlb-improve-page-fault-scalability-fix.patch
pagewalk-update-page-table-walker-core.patch
pagewalk-add-walk_page_vma.patch
smaps-redefine-callback-functions-for-page-table-walker.patch
clear_refs-redefine-callback-functions-for-page-table-walker.patch
pagemap-redefine-callback-functions-for-page-table-walker.patch
numa_maps-redefine-callback-functions-for-page-table-walker.patch
memcg-redefine-callback-functions-for-page-table-walker.patch
madvise-redefine-callback-functions-for-page-table-walker.patch
arch-powerpc-mm-subpage-protc-use-walk_page_vma-instead-of-walk_page_range.patch
pagewalk-remove-argument-hmask-from-hugetlb_entry.patch
mempolicy-apply-page-table-walker-on-queue_pages_range.patch
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