[patch 3/6] mmu_notifier: invalidate_page callbacks

From: Christoph Lameter
Date: Fri Feb 08 2008 - 17:07:22 EST


Two callbacks to remove individual pages as done in rmap code

invalidate_page()

Called from the inner loop of rmap walks to invalidate pages.

age_page()

Called for the determination of the page referenced status.

If we do not care about page referenced status then an age_page callback
may be be omitted. PageLock and pte lock are held when either of the
functions is called.

Signed-off-by: Andrea Arcangeli <andrea@xxxxxxxxxxxx>
Signed-off-by: Robin Holt <holt@xxxxxxx>
Signed-off-by: Christoph Lameter <clameter@xxxxxxx>

---
mm/rmap.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)

Index: linux-2.6/mm/rmap.c
===================================================================
--- linux-2.6.orig/mm/rmap.c 2008-02-07 16:49:32.000000000 -0800
+++ linux-2.6/mm/rmap.c 2008-02-07 17:25:25.000000000 -0800
@@ -49,6 +49,7 @@
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>

#include <asm/tlbflush.h>

@@ -287,7 +288,8 @@ static int page_referenced_one(struct pa
if (vma->vm_flags & VM_LOCKED) {
referenced++;
*mapcount = 1; /* break early from loop */
- } else if (ptep_clear_flush_young(vma, address, pte))
+ } else if (ptep_clear_flush_young(vma, address, pte) |
+ mmu_notifier_age_page(mm, address))
referenced++;

/* Pretend the page is referenced if the task has the
@@ -455,6 +457,7 @@ static int page_mkclean_one(struct page

flush_cache_page(vma, address, pte_pfn(*pte));
entry = ptep_clear_flush(vma, address, pte);
+ mmu_notifier(invalidate_page, mm, address);
entry = pte_wrprotect(entry);
entry = pte_mkclean(entry);
set_pte_at(mm, address, pte, entry);
@@ -712,7 +715,8 @@ static int try_to_unmap_one(struct page
* skipped over this mm) then we should reactivate it.
*/
if (!migration && ((vma->vm_flags & VM_LOCKED) ||
- (ptep_clear_flush_young(vma, address, pte)))) {
+ (ptep_clear_flush_young(vma, address, pte) |
+ mmu_notifier_age_page(mm, address)))) {
ret = SWAP_FAIL;
goto out_unmap;
}
@@ -720,6 +724,7 @@ static int try_to_unmap_one(struct page
/* Nuke the page table entry. */
flush_cache_page(vma, address, page_to_pfn(page));
pteval = ptep_clear_flush(vma, address, pte);
+ mmu_notifier(invalidate_page, mm, address);

/* Move the dirty bit to the physical page now the pte is gone. */
if (pte_dirty(pteval))
@@ -844,12 +849,14 @@ static void try_to_unmap_cluster(unsigne
page = vm_normal_page(vma, address, *pte);
BUG_ON(!page || PageAnon(page));

- if (ptep_clear_flush_young(vma, address, pte))
+ if (ptep_clear_flush_young(vma, address, pte) |
+ mmu_notifier_age_page(mm, address))
continue;

/* Nuke the page table entry. */
flush_cache_page(vma, address, pte_pfn(*pte));
pteval = ptep_clear_flush(vma, address, pte);
+ mmu_notifier(invalidate_page, mm, address);

/* If nonlinear, store the file page offset in the pte. */
if (page->index != linear_page_index(vma, address))

--
--
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