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>

2 files changed, 10 insertions, 5 deletions

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 9d0a830423b6..cc0ad7191acd 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -32,7 +32,8 @@ extern void mm_free_cgroup(struct mm_struct *mm);
 extern void page_assign_page_cgroup(struct page *page,
                                         struct page_cgroup *pc);
 extern struct page_cgroup *page_get_page_cgroup(struct page *page);
-extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm);
+extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+                                gfp_t gfp_mask);
 extern void mem_cgroup_uncharge(struct page_cgroup *pc);
 extern void mem_cgroup_move_lists(struct page_cgroup *pc, bool active);
 extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
@@ -42,7 +43,8 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,
                                         struct mem_cgroup *mem_cont,
                                         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 int mem_cgroup_cache_charge(struct page *page, struct mm_struct *mm,
+                                        gfp_t gfp_mask);
 extern struct mem_cgroup *mm_cgroup(struct mm_struct *mm);
 
 static inline void mem_cgroup_uncharge_page(struct page *page)
@@ -70,7 +72,8 @@ static inline struct page_cgroup *page_get_page_cgroup(struct page *page)
         return NULL;
 }
 
-static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm)
+static inline int mem_cgroup_charge(struct page *page, struct mm_struct *mm,
+                                        gfp_t gfp_mask)
 {
         return 0;
 }
@@ -89,7 +92,8 @@ static inline void mem_cgroup_move_lists(struct page_cgroup *pc,
 }
 
 static inline int mem_cgroup_cache_charge(struct page *page,
-                                                struct mm_struct *mm)
+                                                struct mm_struct *mm,
+                                                gfp_t gfp_mask)
 {
         return 0;
 }
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 4d91bc0e0fd5..3ca5c4bd6d3f 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -183,7 +183,8 @@ extern void swap_setup(void);
 /* linux/mm/vmscan.c */
 extern unsigned long try_to_free_pages(struct zone **zones, int order,
                                         gfp_t gfp_mask);
-extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem);
+extern unsigned long try_to_free_mem_cgroup_pages(struct mem_cgroup *mem,
+                                                        gfp_t gfp_mask);
 extern int __isolate_lru_page(struct page *page, int mode);
 extern unsigned long shrink_all_memory(unsigned long nr_pages);
 extern int vm_swappiness;