Memory controller: make charging gfp mask aware

Nick Piggin pointed out that swap cache and page cache addition routines
could be called from non GFP_KERNEL contexts.  This patch makes the
charging routine aware of the gfp context.  Charging might fail if the
cgroup is over it's limit, in which case a suitable error is returned.

This patch was tested on a Powerpc box.  I am still looking at being able
to test the path, through which allocations happen in non GFP_KERNEL
contexts.

[kamezawa.hiroyu@jp.fujitsu.com: problem with ZONE_MOVABLE]
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: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

7 files changed, 31 insertions, 25 deletions

diff --git a/mm/filemap.c b/mm/filemap.c
index 8ae171cc2811..63040d5e0ae2 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -464,7 +464,7 @@ int add_to_page_cache(struct page *page, struct address_space *mapping,
 
         if (error == 0) {
 
-                error = mem_cgroup_cache_charge(page, current->mm);
+                error = mem_cgroup_cache_charge(page, current->mm, gfp_mask);
                 if (error)
                         goto out;
 
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index ff7cac602984..ac8774426fec 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -261,7 +261,8 @@ unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
  * 0 if the charge was successful
  * < 0 if the cgroup is over its limit
  */
-int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+                                gfp_t gfp_mask)
 {
         struct mem_cgroup *mem;
         struct page_cgroup *pc, *race_pc;
@@ -293,7 +294,7 @@ retry:
 
         unlock_page_cgroup(page);
 
-        pc = kzalloc(sizeof(struct page_cgroup), GFP_KERNEL);
+        pc = kzalloc(sizeof(struct page_cgroup), gfp_mask);
         if (pc == NULL)
                 goto err;
 
@@ -320,7 +321,14 @@ retry:
          * the cgroup limit.
          */
         while (res_counter_charge(&mem->res, PAGE_SIZE)) {
-                if (try_to_free_mem_cgroup_pages(mem))
+                bool is_atomic = gfp_mask & GFP_ATOMIC;
+                /*
+                 * We cannot reclaim under GFP_ATOMIC, fail the charge
+                 */
+                if (is_atomic)
+                        goto noreclaim;
+
+                if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
                         continue;
 
                 /*
@@ -344,9 +352,10 @@ retry:
                         congestion_wait(WRITE, HZ/10);
                         continue;
                 }
-
+noreclaim:
                 css_put(&mem->css);
-                mem_cgroup_out_of_memory(mem, GFP_KERNEL);
+                if (!is_atomic)
+                        mem_cgroup_out_of_memory(mem, GFP_KERNEL);
                 goto free_pc;
         }
 
@@ -385,7 +394,8 @@ err:
 /*
  * See if the cached pages should be charged at all?
  */
-int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm)
+int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+                                gfp_t gfp_mask)
 {
         struct mem_cgroup *mem;
         if (!mm)
@@ -393,7 +403,7 @@ int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm)
 
         mem = rcu_dereference(mm->mem_cgroup);
         if (mem->control_type == MEM_CGROUP_TYPE_ALL)
-                return mem_cgroup_charge(page, mm);
+                return mem_cgroup_charge(page, mm, gfp_mask);
         else
                 return 0;
 }
diff --git a/mm/memory.c b/mm/memory.c
index 0ba224ea6ba4..153a54b2013c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1147,7 +1147,7 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa
         pte_t *pte;
         spinlock_t *ptl;
 
-        retval = mem_cgroup_charge(page, mm);
+        retval = mem_cgroup_charge(page, mm, GFP_KERNEL);
         if (retval)
                 goto out;
 
@@ -1650,7 +1650,7 @@ gotten:
         cow_user_page(new_page, old_page, address, vma);
         __SetPageUptodate(new_page);
 
-        if (mem_cgroup_charge(new_page, mm))
+        if (mem_cgroup_charge(new_page, mm, GFP_KERNEL))
                 goto oom_free_new;
 
         /*
@@ -2052,7 +2052,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 count_vm_event(PGMAJFAULT);
         }
 
-        if (mem_cgroup_charge(page, mm)) {
+        if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
                 delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
                 ret = VM_FAULT_OOM;
                 goto out;
@@ -2139,7 +2139,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 goto oom;
         __SetPageUptodate(page);
 
-        if (mem_cgroup_charge(page, mm))
+        if (mem_cgroup_charge(page, mm, GFP_KERNEL))
                 goto oom_free_page;
 
         entry = mk_pte(page, vma->vm_page_prot);
@@ -2277,7 +2277,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
         }
 
-        if (mem_cgroup_charge(page, mm)) {
+        if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
                 ret = VM_FAULT_OOM;
                 goto out;
         }
diff --git a/mm/migrate.c b/mm/migrate.c
index 417bbda14e5b..763794144697 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -153,7 +153,7 @@ static void remove_migration_pte(struct vm_area_struct *vma,
                 return;
         }
 
-        if (mem_cgroup_charge(new, mm)) {
+        if (mem_cgroup_charge(new, mm, GFP_KERNEL)) {
                 pte_unmap(ptep);
                 return;
         }
diff --git a/mm/swap_state.c b/mm/swap_state.c
index 88258869c8e7..581b609e748d 100644
--- a/mm/swap_state.c
+++ b/mm/swap_state.c
@@ -78,7 +78,7 @@ int add_to_swap_cache(struct page *page, swp_entry_t entry, gfp_t gfp_mask)
         error = radix_tree_preload(gfp_mask);
         if (!error) {
 
-                error = mem_cgroup_cache_charge(page, current->mm);
+                error = mem_cgroup_cache_charge(page, current->mm, gfp_mask);
                 if (error)
                         goto out;
 
diff --git a/mm/swapfile.c b/mm/swapfile.c
index fddc4cc4149b..35e00c3d0286 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -510,7 +510,7 @@ unsigned int count_swap_pages(int type, int free)
 static int unuse_pte(struct vm_area_struct *vma, pte_t *pte,
                 unsigned long addr, swp_entry_t entry, struct page *page)
 {
-        if (mem_cgroup_charge(page, vma->vm_mm))
+        if (mem_cgroup_charge(page, vma->vm_mm, GFP_KERNEL))
                 return -ENOMEM;
 
         inc_mm_counter(vma->vm_mm, anon_rss);
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 215f6a726b2f..b7d868cbca09 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1337,16 +1337,11 @@ unsigned long try_to_free_pages(struct zone **zones, int order, gfp_t gfp_mask)
 
 #ifdef CONFIG_CGROUP_MEM_CONT
 
-#ifdef CONFIG_HIGHMEM
-#define ZONE_USERPAGES ZONE_HIGHMEM
-#else
-#define ZONE_USERPAGES ZONE_NORMAL
-#endif
-
-unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont)
+unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont,
+                                                gfp_t gfp_mask)
 {
         struct scan_control sc = {
-                .gfp_mask = GFP_KERNEL,
+                .gfp_mask = gfp_mask,
                 .may_writepage = !laptop_mode,
                 .may_swap = 1,
                 .swap_cluster_max = SWAP_CLUSTER_MAX,
@@ -1357,9 +1352,10 @@ unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem_cont)
         };
         int node;
         struct zone **zones;
+        int target_zone = gfp_zone(GFP_HIGHUSER_MOVABLE);
 
         for_each_online_node(node) {
-                zones = NODE_DATA(node)->node_zonelists[ZONE_USERPAGES].zones;
+                zones = NODE_DATA(node)->node_zonelists[target_zone].zones;
                 if (do_try_to_free_pages(zones, sc.gfp_mask, &sc))
                         return 1;
         }