提交 ad8c2ee8 编写于 作者: R Rik van Riel 提交者: Linus Torvalds

rmap: add exclusive page to private anon_vma on swapin

On swapin it is fairly common for a page to be owned exclusively by one
process.  In that case we want to add the page to the anon_vma of that
process's VMA, instead of to the root anon_vma.

This will reduce the amount of rmap searching that the swapout code needs
to do.
Signed-off-by: NRik van Riel <riel@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
上级 51b1bd2a
......@@ -162,6 +162,8 @@ static inline void anon_vma_merge(struct vm_area_struct *vma,
*/
void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
void do_page_add_anon_rmap(struct page *, struct vm_area_struct *,
unsigned long, int);
void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
void page_add_file_rmap(struct page *);
void page_remove_rmap(struct page *);
......
......@@ -2628,6 +2628,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
swp_entry_t entry;
pte_t pte;
struct mem_cgroup *ptr = NULL;
int exclusive = 0;
int ret = 0;
if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
......@@ -2722,10 +2723,11 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
flags &= ~FAULT_FLAG_WRITE;
exclusive = 1;
}
flush_icache_page(vma, page);
set_pte_at(mm, address, page_table, pte);
page_add_anon_rmap(page, vma, address);
do_page_add_anon_rmap(page, vma, address, exclusive);
/* It's better to call commit-charge after rmap is established */
mem_cgroup_commit_charge_swapin(page, ptr);
......
......@@ -829,6 +829,17 @@ static void __page_check_anon_rmap(struct page *page,
*/
void page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address)
{
do_page_add_anon_rmap(page, vma, address, 0);
}
/*
* Special version of the above for do_swap_page, which often runs
* into pages that are exclusively owned by the current process.
* Everybody else should continue to use page_add_anon_rmap above.
*/
void do_page_add_anon_rmap(struct page *page,
struct vm_area_struct *vma, unsigned long address, int exclusive)
{
int first = atomic_inc_and_test(&page->_mapcount);
if (first)
......@@ -839,7 +850,7 @@ void page_add_anon_rmap(struct page *page,
VM_BUG_ON(!PageLocked(page));
VM_BUG_ON(address < vma->vm_start || address >= vma->vm_end);
if (first)
__page_set_anon_rmap(page, vma, address, 0);
__page_set_anon_rmap(page, vma, address, exclusive);
else
__page_check_anon_rmap(page, vma, address);
}
......
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