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authorBalbir Singh <balbir@linux.vnet.ibm.com>2008-02-07 00:14:01 -0800
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2008-02-07 08:42:19 -0800
commitbed7161a519a2faef53e1bce1b47595e297c1d14 (patch)
treefbc0541340465f7d83221b829a9382cac2855916 /mm
parent8697d33194faae6fdd6b2e799f6308aa00cfdf67 (diff)
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: Balbir 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: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r--mm/memcontrol.c5
-rw-r--r--mm/rmap.c30
-rw-r--r--mm/vmscan.c4
3 files changed, 31 insertions, 8 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 10833d969e3..ff7cac60298 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -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;
diff --git a/mm/rmap.c b/mm/rmap.c
index 4a3487921ef..a0e92a263d1 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -302,7 +302,8 @@ out:
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);
}
}
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 7408a8a7d88..215f6a726b2 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -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 @@ force_reclaim_mapped:
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;
}