Commit 6fe6b7e3 authored by Wu Fengguang's avatar Wu Fengguang Committed by Linus Torvalds

vmscan: report vm_flags in page_referenced()

Collect vma->vm_flags of the VMAs that actually referenced the page.

This is preparing for more informed reclaim heuristics, eg.  to protect
executable file pages more aggressively.  For now only the VM_EXEC bit
will be used by the caller.

Thanks to Johannes, Peter and Minchan for all the good tips.
Acked-by: default avatarPeter Zijlstra <peterz@infradead.org>
Reviewed-by: default avatarRik van Riel <riel@redhat.com>
Reviewed-by: default avatarMinchan Kim <minchan.kim@gmail.com>
Reviewed-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 608e8e66
......@@ -83,7 +83,8 @@ static inline void page_dup_rmap(struct page *page, struct vm_area_struct *vma,
/*
* Called from mm/vmscan.c to handle paging out
*/
int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt);
int page_referenced(struct page *, int is_locked,
struct mem_cgroup *cnt, unsigned long *vm_flags);
int try_to_unmap(struct page *, int ignore_refs);
/*
......@@ -117,7 +118,7 @@ int try_to_munlock(struct page *);
#define anon_vma_prepare(vma) (0)
#define anon_vma_link(vma) do {} while (0)
#define page_referenced(page,l,cnt) TestClearPageReferenced(page)
#define page_referenced(page, locked, cnt, flags) TestClearPageReferenced(page)
#define try_to_unmap(page, refs) SWAP_FAIL
static inline int page_mkclean(struct page *page)
......
......@@ -333,7 +333,9 @@ static int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
* repeatedly from either page_referenced_anon or page_referenced_file.
*/
static int page_referenced_one(struct page *page,
struct vm_area_struct *vma, unsigned int *mapcount)
struct vm_area_struct *vma,
unsigned int *mapcount,
unsigned long *vm_flags)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long address;
......@@ -381,11 +383,14 @@ static int page_referenced_one(struct page *page,
(*mapcount)--;
pte_unmap_unlock(pte, ptl);
out:
if (referenced)
*vm_flags |= vma->vm_flags;
return referenced;
}
static int page_referenced_anon(struct page *page,
struct mem_cgroup *mem_cont)
struct mem_cgroup *mem_cont,
unsigned long *vm_flags)
{
unsigned int mapcount;
struct anon_vma *anon_vma;
......@@ -405,7 +410,8 @@ static int page_referenced_anon(struct page *page,
*/
if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
continue;
referenced += page_referenced_one(page, vma, &mapcount);
referenced += page_referenced_one(page, vma,
&mapcount, vm_flags);
if (!mapcount)
break;
}
......@@ -418,6 +424,7 @@ static int page_referenced_anon(struct page *page,
* page_referenced_file - referenced check for object-based rmap
* @page: the page we're checking references on.
* @mem_cont: target memory controller
* @vm_flags: collect encountered vma->vm_flags who actually referenced the page
*
* For an object-based mapped page, find all the places it is mapped and
* check/clear the referenced flag. This is done by following the page->mapping
......@@ -427,7 +434,8 @@ static int page_referenced_anon(struct page *page,
* This function is only called from page_referenced for object-based pages.
*/
static int page_referenced_file(struct page *page,
struct mem_cgroup *mem_cont)
struct mem_cgroup *mem_cont,
unsigned long *vm_flags)
{
unsigned int mapcount;
struct address_space *mapping = page->mapping;
......@@ -467,7 +475,8 @@ static int page_referenced_file(struct page *page,
*/
if (mem_cont && !mm_match_cgroup(vma->vm_mm, mem_cont))
continue;
referenced += page_referenced_one(page, vma, &mapcount);
referenced += page_referenced_one(page, vma,
&mapcount, vm_flags);
if (!mapcount)
break;
}
......@@ -481,29 +490,35 @@ static int page_referenced_file(struct page *page,
* @page: the page to test
* @is_locked: caller holds lock on the page
* @mem_cont: target memory controller
* @vm_flags: collect encountered vma->vm_flags who actually referenced the page
*
* Quick test_and_clear_referenced for all mappings to a page,
* returns the number of ptes which referenced the page.
*/
int page_referenced(struct page *page, int is_locked,
struct mem_cgroup *mem_cont)
int page_referenced(struct page *page,
int is_locked,
struct mem_cgroup *mem_cont,
unsigned long *vm_flags)
{
int referenced = 0;
if (TestClearPageReferenced(page))
referenced++;
*vm_flags = 0;
if (page_mapped(page) && page->mapping) {
if (PageAnon(page))
referenced += page_referenced_anon(page, mem_cont);
referenced += page_referenced_anon(page, mem_cont,
vm_flags);
else if (is_locked)
referenced += page_referenced_file(page, mem_cont);
referenced += page_referenced_file(page, mem_cont,
vm_flags);
else if (!trylock_page(page))
referenced++;
else {
if (page->mapping)
referenced +=
page_referenced_file(page, mem_cont);
referenced += page_referenced_file(page,
mem_cont, vm_flags);
unlock_page(page);
}
}
......
......@@ -577,6 +577,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
struct pagevec freed_pvec;
int pgactivate = 0;
unsigned long nr_reclaimed = 0;
unsigned long vm_flags;
cond_resched();
......@@ -627,7 +628,8 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep_locked;
}
referenced = page_referenced(page, 1, sc->mem_cgroup);
referenced = page_referenced(page, 1,
sc->mem_cgroup, &vm_flags);
/* In active use or really unfreeable? Activate it. */
if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
referenced && page_mapping_inuse(page))
......@@ -1208,6 +1210,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
{
unsigned long pgmoved;
unsigned long pgscanned;
unsigned long vm_flags;
LIST_HEAD(l_hold); /* The pages which were snipped off */
LIST_HEAD(l_inactive);
struct page *page;
......@@ -1248,7 +1251,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
/* page_referenced clears PageReferenced */
if (page_mapping_inuse(page) &&
page_referenced(page, 0, sc->mem_cgroup))
page_referenced(page, 0, sc->mem_cgroup, &vm_flags))
pgmoved++;
list_add(&page->lru, &l_inactive);
......
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