This patch is for cleaning up the code of the cgroup memory subsystem
to remove a lot of "#ifdef"s.
Based on 2.6.27-rc1-mm1
Signed-off-by: Ryo Tsuruta <ryov@xxxxxxxxxxxxx>
Signed-off-by: Hirokazu Takahashi <taka@xxxxxxxxxxxxx>
diff -Ndupr linux-2.6.27-rc1-mm1.cg0/mm/memcontrol.c 
linux-2.6.27-rc1-mm1.cg1/mm/memcontrol.c
--- linux-2.6.27-rc1-mm1.cg0/mm/memcontrol.c 2008年09月19日 18:50:26.000000000 
+0900
+++ linux-2.6.27-rc1-mm1.cg1/mm/memcontrol.c 2008年09月19日 18:50:59.000000000 
+0900
@@ -228,6 +228,47 @@ struct mem_cgroup *mem_cgroup_from_task(
 struct mem_cgroup, css);
 }
 
+static inline void get_mem_cgroup(struct mem_cgroup *mem)
+{
+ css_get(&mem->css);
+}
+
+static inline void put_mem_cgroup(struct mem_cgroup *mem)
+{
+ css_put(&mem->css);
+}
+
+static inline void set_mem_cgroup(struct page_cgroup *pc,
+ struct mem_cgroup *mem)
+{
+ pc->mem_cgroup = mem;
+}
+
+static inline void clear_mem_cgroup(struct page_cgroup *pc)
+{
+ struct mem_cgroup *mem = pc->mem_cgroup;
+ res_counter_uncharge(&mem->res, PAGE_SIZE);
+ pc->mem_cgroup = NULL;
+ put_mem_cgroup(mem);
+}
+
+static inline struct mem_cgroup *get_mem_page_cgroup(struct page_cgroup *pc)
+{
+ struct mem_cgroup *mem = pc->mem_cgroup;
+ css_get(&mem->css);
+ return mem;
+}
+
+/* This sould be called in an RCU-protected section. */
+static inline struct mem_cgroup *mm_get_mem_cgroup(struct mm_struct *mm)
+{
+ struct mem_cgroup *mem;
+
+ mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
+ get_mem_cgroup(mem);
+ return mem;
+}
+
 static void __mem_cgroup_remove_list(struct mem_cgroup_per_zone *mz,
 struct page_cgroup *pc)
 {
@@ -297,6 +338,26 @@ static void __mem_cgroup_move_lists(stru
 list_move(&pc->lru, &mz->lists[lru]);
 }
 
+static inline void mem_cgroup_add_page(struct page_cgroup *pc)
+{
+ struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ __mem_cgroup_add_list(mz, pc);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+}
+
+static inline void mem_cgroup_remove_page(struct page_cgroup *pc)
+{
+ struct mem_cgroup_per_zone *mz = page_cgroup_zoneinfo(pc);
+ unsigned long flags;
+
+ spin_lock_irqsave(&mz->lru_lock, flags);
+ __mem_cgroup_remove_list(mz, pc);
+ spin_unlock_irqrestore(&mz->lru_lock, flags);
+}
+
 int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem)
 {
 int ret;
@@ -339,6 +400,36 @@ void mem_cgroup_move_lists(struct page *
 unlock_page_cgroup(page);
 }
 
+static inline int mem_cgroup_try_to_allocate(struct mem_cgroup *mem,
+ gfp_t gfp_mask)
+{
+ unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
+
+ while (res_counter_charge(&mem->res, PAGE_SIZE)) {
+ if (!(gfp_mask & __GFP_WAIT))
+ return -1;
+
+ if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
+ continue;
+
+ /*
+ * try_to_free_mem_cgroup_pages() might not give us a full
+ * picture of reclaim. Some pages are reclaimed and might be
+ * moved to swap cache or just unmapped from the cgroup.
+ * Check the limit again to see if the reclaim reduced the
+ * current usage of the cgroup before giving up
+ */
+ if (res_counter_check_under_limit(&mem->res))
+ continue;
+
+ if (!nr_retries--) {
+ mem_cgroup_out_of_memory(mem, gfp_mask);
+ return -1;
+ }
+ }
+ return 0;
+}
+
 /*
 * Calculate mapped_ratio under memory controller. This will be used in
 * vmscan.c for deteremining we have to reclaim mapped pages.
@@ -469,15 +560,14 @@ int mem_cgroup_shrink_usage(struct mm_st
 return 0;
 
 rcu_read_lock();
- mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
- css_get(&mem->css);
+ mem = mm_get_mem_cgroup(mm);
 rcu_read_unlock();
 
 do {
 progress = try_to_free_mem_cgroup_pages(mem, gfp_mask);
 } while (!progress && --retry);
 
- css_put(&mem->css);
+ put_mem_cgroup(mem);
 if (!retry)
 return -ENOMEM;
 return 0;
@@ -558,7 +648,7 @@ static int mem_cgroup_force_empty(struct
 int ret = -EBUSY;
 int node, zid;
 
- css_get(&mem->css);
+ get_mem_cgroup(mem);
 /*
 * page reclaim code (kswapd etc..) will move pages between
 * active_list <-> inactive_list while we don't take a lock.
@@ -578,7 +668,7 @@ static int mem_cgroup_force_empty(struct
 }
 ret = 0;
 out:
- css_put(&mem->css);
+ put_mem_cgroup(mem);
 return ret;
 }
 
@@ -873,10 +963,37 @@ struct cgroup_subsys mem_cgroup_subsys =
 
 #else /* CONFIG_CGROUP_MEM_RES_CTLR */
 
+struct mem_cgroup;
+
 static inline int mem_cgroup_disabled(void)
 {
 return 1;
 }
+
+static inline void mem_cgroup_add_page(struct page_cgroup *pc) {}
+static inline void mem_cgroup_remove_page(struct page_cgroup *pc) {}
+static inline void get_mem_cgroup(struct mem_cgroup *mem) {}
+static inline void put_mem_cgroup(struct mem_cgroup *mem) {}
+static inline void set_mem_cgroup(struct page_cgroup *pc,
+ struct mem_cgroup *mem) {}
+static inline void clear_mem_cgroup(struct page_cgroup *pc) {}
+
+static inline struct mem_cgroup *get_mem_page_cgroup(struct page_cgroup *pc)
+{
+ return NULL;
+}
+
+static inline struct mem_cgroup *mm_get_mem_cgroup(struct mm_struct *mm)
+{
+ return NULL;
+}
+
+static inline int mem_cgroup_try_to_allocate(struct mem_cgroup *mem,
+ gfp_t gfp_mask)
+{
+ return 0;
+}
+
 #endif /* CONFIG_CGROUP_MEM_RES_CTLR */
 
 static inline int page_cgroup_locked(struct page *page)
@@ -906,12 +1023,7 @@ static int mem_cgroup_charge_common(stru
 struct mem_cgroup *memcg)
 {
 struct page_cgroup *pc;
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
 struct mem_cgroup *mem;
- unsigned long flags;
- unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;
- struct mem_cgroup_per_zone *mz;
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
 
 pc = kmem_cache_alloc(page_cgroup_cache, gfp_mask);
 if (unlikely(pc == NULL))
@@ -925,47 +1037,16 @@ static int mem_cgroup_charge_common(stru
 */
 if (likely(!memcg)) {
 rcu_read_lock();
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
- /*
- * For every charge from the cgroup, increment reference count
- */
- css_get(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ mem = mm_get_mem_cgroup(mm);
 rcu_read_unlock();
 } else {
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
 mem = memcg;
- css_get(&memcg->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
- }
-
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- while (res_counter_charge(&mem->res, PAGE_SIZE)) {
- if (!(gfp_mask & __GFP_WAIT))
- goto out;
-
- if (try_to_free_mem_cgroup_pages(mem, gfp_mask))
- continue;
-
- /*
- * try_to_free_mem_cgroup_pages() might not give us a full
- * picture of reclaim. Some pages are reclaimed and might be
- * moved to swap cache or just unmapped from the cgroup.
- * Check the limit again to see if the reclaim reduced the
- * current usage of the cgroup before giving up
- */
- if (res_counter_check_under_limit(&mem->res))
- continue;
-
- if (!nr_retries--) {
- mem_cgroup_out_of_memory(mem, gfp_mask);
- goto out;
- }
+ get_mem_cgroup(mem);
 }
- pc->mem_cgroup = mem;
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
 
+ if (mem_cgroup_try_to_allocate(mem, gfp_mask) < 0)
+ goto out;
+ set_mem_cgroup(pc, mem);
 pc->page = page;
 /*
 * If a page is accounted as a page cache, insert to inactive list.
@@ -983,29 +1064,19 @@ static int mem_cgroup_charge_common(stru
 lock_page_cgroup(page);
 if (unlikely(page_get_page_cgroup(page))) {
 unlock_page_cgroup(page);
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- css_put(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ clear_mem_cgroup(pc);
 kmem_cache_free(page_cgroup_cache, pc);
 goto done;
 }
 page_assign_page_cgroup(page, pc);
 
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- mz = page_cgroup_zoneinfo(pc);
- spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_add_list(mz, pc);
- spin_unlock_irqrestore(&mz->lru_lock, flags);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ mem_cgroup_add_page(pc);
 
 unlock_page_cgroup(page);
 done:
 return 0;
 out:
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- css_put(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ put_mem_cgroup(mem);
 kmem_cache_free(page_cgroup_cache, pc);
 err:
 return -ENOMEM;
@@ -1074,11 +1145,6 @@ static void
 __mem_cgroup_uncharge_common(struct page *page, enum charge_type ctype)
 {
 struct page_cgroup *pc;
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- struct mem_cgroup *mem;
- struct mem_cgroup_per_zone *mz;
- unsigned long flags;
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
 
 if (mem_cgroup_disabled())
 return;
@@ -1098,21 +1164,12 @@ __mem_cgroup_uncharge_common(struct page
 || page_mapped(page)))
 goto unlock;
 
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- mz = page_cgroup_zoneinfo(pc);
- spin_lock_irqsave(&mz->lru_lock, flags);
- __mem_cgroup_remove_list(mz, pc);
- spin_unlock_irqrestore(&mz->lru_lock, flags);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ mem_cgroup_remove_page(pc);
 
 page_assign_page_cgroup(page, NULL);
 unlock_page_cgroup(page);
 
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- mem = pc->mem_cgroup;
- res_counter_uncharge(&mem->res, PAGE_SIZE);
- css_put(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ clear_mem_cgroup(pc);
 
 kmem_cache_free(page_cgroup_cache, pc);
 return;
@@ -1147,10 +1204,7 @@ int mem_cgroup_prepare_migration(struct 
 lock_page_cgroup(page);
 pc = page_get_page_cgroup(page);
 if (pc) {
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- mem = pc->mem_cgroup;
- css_get(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ mem = get_mem_page_cgroup(pc);
 if (pc->flags & PAGE_CGROUP_FLAG_CACHE)
 ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
 }
@@ -1158,9 +1212,7 @@ int mem_cgroup_prepare_migration(struct 
 if (mem) {
 ret = mem_cgroup_charge_common(newpage, NULL, GFP_KERNEL,
 ctype, mem);
-#ifdef CONFIG_CGROUP_MEM_RES_CTLR
- css_put(&mem->css);
-#endif /* CONFIG_CGROUP_MEM_RES_CTLR */
+ put_mem_cgroup(mem);
 }
 return ret;
 }
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