Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On 10/12/2012 12:13 PM, Kirill A. Shutemov wrote:
On Fri, Oct 12, 2012 at 11:23:37AM +0800, Ni zhan Chen wrote:
On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
From: "Kirill A. Shutemov"
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov
Reviewed-by: Andrea Arcangeli
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
why I can't find function pmdp_clear_flush_notify in kernel source
code? Do you mean pmdp_clear_flush_young_notify or something like
that?
It was changed recently. See commit
2ec74c3 mm: move all mmu notifier invocations to be done outside the PT lock
Oh, thanks!
--
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Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On Fri, Oct 12, 2012 at 11:23:37AM +0800, Ni zhan Chen wrote:
> On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
> >From: "Kirill A. Shutemov"
> >
> >We can't split huge zero page itself, but we can split the pmd which
> >points to it.
> >
> >On splitting the pmd we create a table with all ptes set to normal zero
> >page.
> >
> >Signed-off-by: Kirill A. Shutemov
> >Reviewed-by: Andrea Arcangeli
> >---
> > mm/huge_memory.c | 32
> > 1 files changed, 32 insertions(+), 0 deletions(-)
> >
> >diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> >index 95032d3..3f1c59c 100644
> >--- a/mm/huge_memory.c
> >+++ b/mm/huge_memory.c
> >@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
> > struct anon_vma *anon_vma;
> > int ret = 1;
> >+BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
> > BUG_ON(!PageAnon(page));
> > anon_vma = page_lock_anon_vma(page);
> > if (!anon_vma)
> >@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
> > return 0;
> > }
> >+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
> >+unsigned long haddr, pmd_t *pmd)
> >+{
> >+pgtable_t pgtable;
> >+pmd_t _pmd;
> >+int i;
> >+
> >+pmdp_clear_flush_notify(vma, haddr, pmd);
>
> why I can't find function pmdp_clear_flush_notify in kernel source
> code? Do you mean pmdp_clear_flush_young_notify or something like
> that?
It was changed recently. See commit
2ec74c3 mm: move all mmu notifier invocations to be done outside the PT lock
--
Kirill A. Shutemov
--
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Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
From: "Kirill A. Shutemov"
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov
Reviewed-by: Andrea Arcangeli
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
why I can't find function pmdp_clear_flush_notify in kernel source code?
Do you mean pmdp_clear_flush_young_notify or something like that?
+ /* leave pmd empty until pte is filled */
+
+ pgtable = get_pmd_huge_pte(vma->vm_mm);
+ pmd_populate(vma->vm_mm, &_pmd, pgtable);
+
+ for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot);
+ entry = pte_mkspecial(entry);
+ pte = pte_offset_map(&_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(vma->vm_mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(vma->vm_mm, pmd, pgtable);
+}
+
void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmd)
{
@@ -2516,6 +2543,11 @@ void __split_huge_page_pmd(struct vm_area_struct *vma,
unsigned long address,
spin_unlock(>vm_mm->page_table_lock);
return;
}
+ if (is_huge_zero_pmd(*pmd)) {
+ __split_huge_zero_page_pmd(vma, haddr, pmd);
+ spin_unlock(>vm_mm->page_table_lock);
+ return;
+ }
page = pmd_page(*pmd);
VM_BUG_ON(!page_count(page));
get_page(page);
--
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Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
From: Kirill A. Shutemov kirill.shute...@linux.intel.com
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com
Reviewed-by: Andrea Arcangeli aarca...@redhat.com
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
why I can't find function pmdp_clear_flush_notify in kernel source code?
Do you mean pmdp_clear_flush_young_notify or something like that?
+ /* leave pmd empty until pte is filled */
+
+ pgtable = get_pmd_huge_pte(vma-vm_mm);
+ pmd_populate(vma-vm_mm, _pmd, pgtable);
+
+ for (i = 0; i HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = pfn_pte(my_zero_pfn(haddr), vma-vm_page_prot);
+ entry = pte_mkspecial(entry);
+ pte = pte_offset_map(_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(vma-vm_mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(vma-vm_mm, pmd, pgtable);
+}
+
void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmd)
{
@@ -2516,6 +2543,11 @@ void __split_huge_page_pmd(struct vm_area_struct *vma,
unsigned long address,
spin_unlock(vma-vm_mm-page_table_lock);
return;
}
+ if (is_huge_zero_pmd(*pmd)) {
+ __split_huge_zero_page_pmd(vma, haddr, pmd);
+ spin_unlock(vma-vm_mm-page_table_lock);
+ return;
+ }
page = pmd_page(*pmd);
VM_BUG_ON(!page_count(page));
get_page(page);
--
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On Fri, Oct 12, 2012 at 11:23:37AM +0800, Ni zhan Chen wrote:
On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
From: Kirill A. Shutemov kirill.shute...@linux.intel.com
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com
Reviewed-by: Andrea Arcangeli aarca...@redhat.com
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+unsigned long haddr, pmd_t *pmd)
+{
+pgtable_t pgtable;
+pmd_t _pmd;
+int i;
+
+pmdp_clear_flush_notify(vma, haddr, pmd);
why I can't find function pmdp_clear_flush_notify in kernel source
code? Do you mean pmdp_clear_flush_young_notify or something like
that?
It was changed recently. See commit
2ec74c3 mm: move all mmu notifier invocations to be done outside the PT lock
--
Kirill A. Shutemov
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v3 07/10] thp: implement splitting pmd for huge zero page
On 10/12/2012 12:13 PM, Kirill A. Shutemov wrote:
On Fri, Oct 12, 2012 at 11:23:37AM +0800, Ni zhan Chen wrote:
On 10/02/2012 11:19 PM, Kirill A. Shutemov wrote:
From: Kirill A. Shutemov kirill.shute...@linux.intel.com
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com
Reviewed-by: Andrea Arcangeli aarca...@redhat.com
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
why I can't find function pmdp_clear_flush_notify in kernel source
code? Do you mean pmdp_clear_flush_young_notify or something like
that?
It was changed recently. See commit
2ec74c3 mm: move all mmu notifier invocations to be done outside the PT lock
Oh, thanks!
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3 07/10] thp: implement splitting pmd for huge zero page
From: "Kirill A. Shutemov"
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov
Reviewed-by: Andrea Arcangeli
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
+ /* leave pmd empty until pte is filled */
+
+ pgtable = get_pmd_huge_pte(vma->vm_mm);
+ pmd_populate(vma->vm_mm, &_pmd, pgtable);
+
+ for (i = 0; i < HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = pfn_pte(my_zero_pfn(haddr), vma->vm_page_prot);
+ entry = pte_mkspecial(entry);
+ pte = pte_offset_map(&_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(vma->vm_mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(vma->vm_mm, pmd, pgtable);
+}
+
void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmd)
{
@@ -2516,6 +2543,11 @@ void __split_huge_page_pmd(struct vm_area_struct *vma,
unsigned long address,
spin_unlock(>vm_mm->page_table_lock);
return;
}
+ if (is_huge_zero_pmd(*pmd)) {
+ __split_huge_zero_page_pmd(vma, haddr, pmd);
+ spin_unlock(>vm_mm->page_table_lock);
+ return;
+ }
page = pmd_page(*pmd);
VM_BUG_ON(!page_count(page));
get_page(page);
--
1.7.7.6
--
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Please read the FAQ at http://www.tux.org/lkml/
[PATCH v3 07/10] thp: implement splitting pmd for huge zero page
From: Kirill A. Shutemov kirill.shute...@linux.intel.com
We can't split huge zero page itself, but we can split the pmd which
points to it.
On splitting the pmd we create a table with all ptes set to normal zero
page.
Signed-off-by: Kirill A. Shutemov kirill.shute...@linux.intel.com
Reviewed-by: Andrea Arcangeli aarca...@redhat.com
---
mm/huge_memory.c | 32
1 files changed, 32 insertions(+), 0 deletions(-)
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 95032d3..3f1c59c 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1600,6 +1600,7 @@ int split_huge_page(struct page *page)
struct anon_vma *anon_vma;
int ret = 1;
+ BUG_ON(is_huge_zero_pfn(page_to_pfn(page)));
BUG_ON(!PageAnon(page));
anon_vma = page_lock_anon_vma(page);
if (!anon_vma)
@@ -2503,6 +2504,32 @@ static int khugepaged(void *none)
return 0;
}
+static void __split_huge_zero_page_pmd(struct vm_area_struct *vma,
+ unsigned long haddr, pmd_t *pmd)
+{
+ pgtable_t pgtable;
+ pmd_t _pmd;
+ int i;
+
+ pmdp_clear_flush_notify(vma, haddr, pmd);
+ /* leave pmd empty until pte is filled */
+
+ pgtable = get_pmd_huge_pte(vma-vm_mm);
+ pmd_populate(vma-vm_mm, _pmd, pgtable);
+
+ for (i = 0; i HPAGE_PMD_NR; i++, haddr += PAGE_SIZE) {
+ pte_t *pte, entry;
+ entry = pfn_pte(my_zero_pfn(haddr), vma-vm_page_prot);
+ entry = pte_mkspecial(entry);
+ pte = pte_offset_map(_pmd, haddr);
+ VM_BUG_ON(!pte_none(*pte));
+ set_pte_at(vma-vm_mm, haddr, pte, entry);
+ pte_unmap(pte);
+ }
+ smp_wmb(); /* make pte visible before pmd */
+ pmd_populate(vma-vm_mm, pmd, pgtable);
+}
+
void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
pmd_t *pmd)
{
@@ -2516,6 +2543,11 @@ void __split_huge_page_pmd(struct vm_area_struct *vma,
unsigned long address,
spin_unlock(vma-vm_mm-page_table_lock);
return;
}
+ if (is_huge_zero_pmd(*pmd)) {
+ __split_huge_zero_page_pmd(vma, haddr, pmd);
+ spin_unlock(vma-vm_mm-page_table_lock);
+ return;
+ }
page = pmd_page(*pmd);
VM_BUG_ON(!page_count(page));
get_page(page);
--
1.7.7.6
--
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