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Diffstat (limited to 'mm/rmap.c')
-rw-r--r--mm/rmap.c69
1 files changed, 35 insertions, 34 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index bf0a5b7cfb8e..0383acfcb068 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -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>
@@ -138,7 +139,7 @@ void anon_vma_unlink(struct vm_area_struct *vma)
anon_vma_free(anon_vma);
}
-static void anon_vma_ctor(struct kmem_cache *cachep, void *data)
+static void anon_vma_ctor(void *data)
{
struct anon_vma *anon_vma = data;
@@ -223,10 +224,14 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
/*
* Check that @page is mapped at @address into @mm.
*
+ * If @sync is false, page_check_address may perform a racy check to avoid
+ * the page table lock when the pte is not present (helpful when reclaiming
+ * highly shared pages).
+ *
* On success returns with pte mapped and locked.
*/
pte_t *page_check_address(struct page *page, struct mm_struct *mm,
- unsigned long address, spinlock_t **ptlp)
+ unsigned long address, spinlock_t **ptlp, int sync)
{
pgd_t *pgd;
pud_t *pud;
@@ -248,7 +253,7 @@ pte_t *page_check_address(struct page *page, struct mm_struct *mm,
pte = pte_offset_map(pmd, address);
/* Make a quick check before getting the lock */
- if (!pte_present(*pte)) {
+ if (!sync && !pte_present(*pte)) {
pte_unmap(pte);
return NULL;
}
@@ -280,14 +285,14 @@ static int page_referenced_one(struct page *page,
if (address == -EFAULT)
goto out;
- pte = page_check_address(page, mm, address, &ptl);
+ pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
goto out;
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_notify(vma, address, pte))
referenced++;
/* Pretend the page is referenced if the task has the
@@ -421,7 +426,7 @@ int page_referenced(struct page *page, int is_locked,
referenced += page_referenced_anon(page, mem_cont);
else if (is_locked)
referenced += page_referenced_file(page, mem_cont);
- else if (TestSetPageLocked(page))
+ else if (!trylock_page(page))
referenced++;
else {
if (page->mapping)
@@ -449,7 +454,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
if (address == -EFAULT)
goto out;
- pte = page_check_address(page, mm, address, &ptl);
+ pte = page_check_address(page, mm, address, &ptl, 1);
if (!pte)
goto out;
@@ -457,7 +462,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma)
pte_t entry;
flush_cache_page(vma, address, pte_pfn(*pte));
- entry = ptep_clear_flush(vma, address, pte);
+ entry = ptep_clear_flush_notify(vma, address, pte);
entry = pte_wrprotect(entry);
entry = pte_mkclean(entry);
set_pte_at(mm, address, pte, entry);
@@ -576,14 +581,8 @@ void page_add_anon_rmap(struct page *page,
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
if (atomic_inc_and_test(&page->_mapcount))
__page_set_anon_rmap(page, vma, address);
- else {
+ else
__page_check_anon_rmap(page, vma, address);
- /*
- * We unconditionally charged during prepare, we uncharge here
- * This takes care of balancing the reference counts
- */
- mem_cgroup_uncharge_page(page);
- }
}
/**
@@ -614,12 +613,6 @@ void page_add_file_rmap(struct page *page)
{
if (atomic_inc_and_test(&page->_mapcount))
__inc_zone_page_state(page, NR_FILE_MAPPED);
- else
- /*
- * We unconditionally charged during prepare, we uncharge here
- * This takes care of balancing the reference counts
- */
- mem_cgroup_uncharge_page(page);
}
#ifdef CONFIG_DEBUG_VM
@@ -670,6 +663,22 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
}
/*
+ * Now that the last pte has gone, s390 must transfer dirty
+ * flag from storage key to struct page. We can usually skip
+ * this if the page is anon, so about to be freed; but perhaps
+ * not if it's in swapcache - there might be another pte slot
+ * containing the swap entry, but page not yet written to swap.
+ */
+ if ((!PageAnon(page) || PageSwapCache(page)) &&
+ page_test_dirty(page)) {
+ page_clear_dirty(page);
+ set_page_dirty(page);
+ }
+
+ mem_cgroup_uncharge_page(page);
+ __dec_zone_page_state(page,
+ PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
+ /*
* It would be tidy to reset the PageAnon mapping here,
* but that might overwrite a racing page_add_anon_rmap
* which increments mapcount after us but sets mapping
@@ -678,14 +687,6 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma)
* Leaving it set also helps swapoff to reinstate ptes
* faster for those pages still in swapcache.
*/
- if (page_test_dirty(page)) {
- page_clear_dirty(page);
- set_page_dirty(page);
- }
- mem_cgroup_uncharge_page(page);
-
- __dec_zone_page_state(page,
- PageAnon(page) ? NR_ANON_PAGES : NR_FILE_MAPPED);
}
}
@@ -707,7 +708,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
if (address == -EFAULT)
goto out;
- pte = page_check_address(page, mm, address, &ptl);
+ pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
goto out;
@@ -717,14 +718,14 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
* 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_notify(vma, address, pte)))) {
ret = SWAP_FAIL;
goto out_unmap;
}
/* Nuke the page table entry. */
flush_cache_page(vma, address, page_to_pfn(page));
- pteval = ptep_clear_flush(vma, address, pte);
+ pteval = ptep_clear_flush_notify(vma, address, pte);
/* Move the dirty bit to the physical page now the pte is gone. */
if (pte_dirty(pteval))
@@ -849,12 +850,12 @@ static void try_to_unmap_cluster(unsigned long cursor,
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_notify(vma, address, pte))
continue;
/* Nuke the page table entry. */
flush_cache_page(vma, address, pte_pfn(*pte));
- pteval = ptep_clear_flush(vma, address, pte);
+ pteval = ptep_clear_flush_notify(vma, address, pte);
/* If nonlinear, store the file page offset in the pte. */
if (page->index != linear_page_index(vma, address))
generated by cgit v1.2.3 (git 2.39.0) at 2024-10-08 09:42:43 +0300