[PATCH 2/5] bio-cgroup: Remove a lot of "#ifdef"s

From: Ryo Tsuruta
Date: Fri Sep 19 2008 - 07:02:37 EST


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 2008-09-19 18:50:26.000000000 +0900
+++ linux-2.6.27-rc1-mm1.cg1/mm/memcontrol.c 2008-09-19 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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