Commit bed7161a authored by Balbir Singh's avatar Balbir Singh Committed by Linus Torvalds

Memory controller: make page_referenced() cgroup aware

Make page_referenced() cgroup aware.  Without this patch, page_referenced()
can cause a page to be skipped while reclaiming pages.  This patch ensures
that other cgroups do not hold pages in a particular cgroup hostage.  It
is required to ensure that shared pages are freed from a cgroup when they
are not actively referenced from the cgroup that brought them in
Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Paul Menage <menage@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: David Rientjes <rientjes@google.com>
Cc: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8697d331
......@@ -43,6 +43,7 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
int active);
extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask);
extern int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm);
extern struct mem_cgroup *mm_cgroup(struct mm_struct *mm);
static inline void mem_cgroup_uncharge_page(struct page *page)
{
......@@ -93,6 +94,11 @@ static inline int mem_cgroup_cache_charge(struct page *page,
return 0;
}
static inline struct mem_cgroup *mm_cgroup(struct mm_struct *mm)
{
return NULL;
}
#endif /* CONFIG_CGROUP_MEM_CONT */
#endif /* _LINUX_MEMCONTROL_H */
......
......@@ -8,6 +8,7 @@
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/spinlock.h>
#include <linux/memcontrol.h>
/*
* The anon_vma heads a list of private "related" vmas, to scan if
......@@ -86,7 +87,7 @@ 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);
int page_referenced(struct page *, int is_locked, struct mem_cgroup *cnt);
int try_to_unmap(struct page *, int ignore_refs);
/*
......@@ -114,7 +115,7 @@ int page_mkclean(struct page *);
#define anon_vma_prepare(vma) (0)
#define anon_vma_link(vma) do {} while (0)
#define page_referenced(page,l) TestClearPageReferenced(page)
#define page_referenced(page,l,cnt) TestClearPageReferenced(page)
#define try_to_unmap(page, refs) SWAP_FAIL
static inline int page_mkclean(struct page *page)
......
......@@ -110,6 +110,11 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p)
struct mem_cgroup, css);
}
inline struct mem_cgroup *mm_cgroup(struct mm_struct *mm)
{
return rcu_dereference(mm->mem_cgroup);
}
void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p)
{
struct mem_cgroup *mem;
......
......@@ -302,7 +302,8 @@ static int page_referenced_one(struct page *page,
return referenced;
}
static int page_referenced_anon(struct page *page)
static int page_referenced_anon(struct page *page,
struct mem_cgroup *mem_cont)
{
unsigned int mapcount;
struct anon_vma *anon_vma;
......@@ -315,6 +316,13 @@ static int page_referenced_anon(struct page *page)
mapcount = page_mapcount(page);
list_for_each_entry(vma, &anon_vma->head, anon_vma_node) {
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
* cgroups
*/
if (mem_cont && (mm_cgroup(vma->vm_mm) != mem_cont))
continue;
referenced += page_referenced_one(page, vma, &mapcount);
if (!mapcount)
break;
......@@ -335,7 +343,8 @@ 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)
static int page_referenced_file(struct page *page,
struct mem_cgroup *mem_cont)
{
unsigned int mapcount;
struct address_space *mapping = page->mapping;
......@@ -368,6 +377,13 @@ static int page_referenced_file(struct page *page)
mapcount = page_mapcount(page);
vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
/*
* If we are reclaiming on behalf of a cgroup, skip
* counting on behalf of references from different
* cgroups
*/
if (mem_cont && (mm_cgroup(vma->vm_mm) != mem_cont))
continue;
if ((vma->vm_flags & (VM_LOCKED|VM_MAYSHARE))
== (VM_LOCKED|VM_MAYSHARE)) {
referenced++;
......@@ -390,7 +406,8 @@ static int page_referenced_file(struct page *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)
int page_referenced(struct page *page, int is_locked,
struct mem_cgroup *mem_cont)
{
int referenced = 0;
......@@ -402,14 +419,15 @@ int page_referenced(struct page *page, int is_locked)
if (page_mapped(page) && page->mapping) {
if (PageAnon(page))
referenced += page_referenced_anon(page);
referenced += page_referenced_anon(page, mem_cont);
else if (is_locked)
referenced += page_referenced_file(page);
referenced += page_referenced_file(page, mem_cont);
else if (TestSetPageLocked(page))
referenced++;
else {
if (page->mapping)
referenced += page_referenced_file(page);
referenced +=
page_referenced_file(page, mem_cont);
unlock_page(page);
}
}
......
......@@ -503,7 +503,7 @@ static unsigned long shrink_page_list(struct list_head *page_list,
goto keep_locked;
}
referenced = page_referenced(page, 1);
referenced = page_referenced(page, 1, sc->mem_cgroup);
/* In active use or really unfreeable? Activate it. */
if (sc->order <= PAGE_ALLOC_COSTLY_ORDER &&
referenced && page_mapping_inuse(page))
......@@ -1057,7 +1057,7 @@ static void shrink_active_list(unsigned long nr_pages, struct zone *zone,
if (page_mapped(page)) {
if (!reclaim_mapped ||
(total_swap_pages == 0 && PageAnon(page)) ||
page_referenced(page, 0)) {
page_referenced(page, 0, sc->mem_cgroup)) {
list_add(&page->lru, &l_active);
continue;
}
......
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