[RFC] memcg: move definitions to .h and inline some functions

[Wu Fengguang]

On Tue, Aug 18, 2009 at 11:57:52PM +0800, KOSAKI Motohiro wrote:
> 
> > > This one of the reasons why we unconditionally deactivate
> > > the active anon pages, and do background scanning of the
> > > active anon list when reclaiming page cache pages.
> > > 
> > > We want to always move some pages to the inactive anon
> > > list, so it does not get too small.
> > 
> > Right, the current code tries to pull inactive list out of
> > smallish-size state as long as there are vmscan activities.
> > 
> > However there is a possible (and tricky) hole: mem cgroups
> > don't do batched vmscan. shrink_zone() may call shrink_list()
> > with nr_to_scan=1, in which case shrink_list() _still_ calls
> > isolate_pages() with the much larger SWAP_CLUSTER_MAX.
> > 
> > It effectively scales up the inactive list scan rate by 10 times when
> > it is still small, and may thus prevent it from growing up for ever.
> > 
> > In that case, LRU becomes FIFO.
> > 
> > Jeff, can you confirm if the mem cgroup's inactive list is small?
> > If so, this patch should help.
> 
> This patch does right thing.
> However, I would explain why I and memcg folks didn't do that in past days.
> 
> Strangely, some memcg struct declaration is hide in *.c. Thus we can't
> make inline function and we hesitated to introduce many function calling
> overhead.
> 
> So, Can we move some memcg structure declaration to *.h and make 
> mem_cgroup_get_saved_scan() inlined function?

OK here it is. I have to move big chunks to make it compile, and it
does reduced a dozen lines of code :)

Is this big copy&paste acceptable? (memcg developers CCed).

Thanks,
Fengguang
---

memcg: move definitions to .h and inline some functions

So as to make inline functions.

Signed-off-by: Wu Fengguang <fengguang.wu@xxxxxxxxx>
---
 include/linux/memcontrol.h |  154 ++++++++++++++++++++++++++++++-----
 mm/memcontrol.c            |  131 -----------------------------
 2 files changed, 134 insertions(+), 151 deletions(-)

--- linux.orig/include/linux/memcontrol.h	2009-08-19 20:18:55.000000000 +0800
+++ linux/include/linux/memcontrol.h	2009-08-19 20:51:06.000000000 +0800
@@ -20,11 +20,144 @@
 #ifndef _LINUX_MEMCONTROL_H
 #define _LINUX_MEMCONTROL_H
 #include <linux/cgroup.h>
-struct mem_cgroup;
+#include <linux/res_counter.h>
 struct page_cgroup;
 struct page;
 struct mm_struct;
 
+/*
+ * Statistics for memory cgroup.
+ */
+enum mem_cgroup_stat_index {
+	/*
+	 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
+	 */
+	MEM_CGROUP_STAT_CACHE,		/* # of pages charged as cache */
+	MEM_CGROUP_STAT_RSS,		/* # of pages charged as anon rss */
+	MEM_CGROUP_STAT_MAPPED_FILE,	/* # of pages charged as file rss */
+	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */
+	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */
+
+	MEM_CGROUP_STAT_NSTATS,
+};
+
+struct mem_cgroup_stat_cpu {
+	s64 count[MEM_CGROUP_STAT_NSTATS];
+} ____cacheline_aligned_in_smp;
+
+struct mem_cgroup_stat {
+	struct mem_cgroup_stat_cpu cpustat[0];
+};
+
+/*
+ * per-zone information in memory controller.
+ */
+struct mem_cgroup_per_zone {
+	/*
+	 * spin_lock to protect the per cgroup LRU
+	 */
+	struct list_head	lists[NR_LRU_LISTS];
+	unsigned long		count[NR_LRU_LISTS];
+
+	struct zone_reclaim_stat reclaim_stat;
+};
+/* Macro for accessing counter */
+#define MEM_CGROUP_ZSTAT(mz, idx)	((mz)->count[(idx)])
+
+struct mem_cgroup_per_node {
+	struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
+};
+
+struct mem_cgroup_lru_info {
+	struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
+};
+
+/*
+ * The memory controller data structure. The memory controller controls both
+ * page cache and RSS per cgroup. We would eventually like to provide
+ * statistics based on the statistics developed by Rik Van Riel for clock-pro,
+ * to help the administrator determine what knobs to tune.
+ *
+ * TODO: Add a water mark for the memory controller. Reclaim will begin when
+ * we hit the water mark. May be even add a low water mark, such that
+ * no reclaim occurs from a cgroup at it's low water mark, this is
+ * a feature that will be implemented much later in the future.
+ */
+struct mem_cgroup {
+	struct cgroup_subsys_state css;
+	/*
+	 * the counter to account for memory usage
+	 */
+	struct res_counter res;
+	/*
+	 * the counter to account for mem+swap usage.
+	 */
+	struct res_counter memsw;
+	/*
+	 * Per cgroup active and inactive list, similar to the
+	 * per zone LRU lists.
+	 */
+	struct mem_cgroup_lru_info info;
+
+	/*
+	  protect against reclaim related member.
+	*/
+	spinlock_t reclaim_param_lock;
+
+	int	prev_priority;	/* for recording reclaim priority */
+
+	/*
+	 * While reclaiming in a hiearchy, we cache the last child we
+	 * reclaimed from.
+	 */
+	int last_scanned_child;
+	/*
+	 * Should the accounting and control be hierarchical, per subtree?
+	 */
+	bool use_hierarchy;
+	unsigned long	last_oom_jiffies;
+	atomic_t	refcnt;
+
+	unsigned int	swappiness;
+
+	/* set when res.limit == memsw.limit */
+	bool		memsw_is_minimum;
+
+	/*
+	 * statistics. This must be placed at the end of memcg.
+	 */
+	struct mem_cgroup_stat stat;
+};
+
+static inline struct mem_cgroup_per_zone *
+mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
+{
+	return &mem->info.nodeinfo[nid]->zoneinfo[zid];
+}
+
+static inline unsigned long
+mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
+			 struct zone *zone,
+			 enum lru_list lru)
+{
+	int nid = zone->zone_pgdat->node_id;
+	int zid = zone_idx(zone);
+	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+	return MEM_CGROUP_ZSTAT(mz, lru);
+}
+
+static inline struct zone_reclaim_stat *
+mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, struct zone *zone)
+{
+	int nid = zone->zone_pgdat->node_id;
+	int zid = zone_idx(zone);
+	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
+
+	return &mz->reclaim_stat;
+}
+
+
 #ifdef CONFIG_CGROUP_MEM_RES_CTLR
 /*
  * All "charge" functions with gfp_mask should use GFP_KERNEL or
@@ -95,11 +228,6 @@ extern void mem_cgroup_record_reclaim_pr
 							int priority);
 int mem_cgroup_inactive_anon_is_low(struct mem_cgroup *memcg);
 int mem_cgroup_inactive_file_is_low(struct mem_cgroup *memcg);
-unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
-				       struct zone *zone,
-				       enum lru_list lru);
-struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
-						      struct zone *zone);
 struct zone_reclaim_stat*
 mem_cgroup_get_reclaim_stat_from_page(struct page *page);
 extern void mem_cgroup_print_oom_info(struct mem_cgroup *memcg,
@@ -246,20 +374,6 @@ mem_cgroup_inactive_file_is_low(struct m
 	return 1;
 }
 
-static inline unsigned long
-mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg, struct zone *zone,
-			 enum lru_list lru)
-{
-	return 0;
-}
-
-
-static inline struct zone_reclaim_stat*
-mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg, struct zone *zone)
-{
-	return NULL;
-}
-
 static inline struct zone_reclaim_stat*
 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 {
--- linux.orig/mm/memcontrol.c	2009-08-19 20:14:56.000000000 +0800
+++ linux/mm/memcontrol.c	2009-08-19 20:46:50.000000000 +0800
@@ -55,30 +55,6 @@ static int really_do_swap_account __init
 static DEFINE_MUTEX(memcg_tasklist);	/* can be hold under cgroup_mutex */
 
 /*
- * Statistics for memory cgroup.
- */
-enum mem_cgroup_stat_index {
-	/*
-	 * For MEM_CONTAINER_TYPE_ALL, usage = pagecache + rss.
-	 */
-	MEM_CGROUP_STAT_CACHE, 	   /* # of pages charged as cache */
-	MEM_CGROUP_STAT_RSS,	   /* # of pages charged as anon rss */
-	MEM_CGROUP_STAT_MAPPED_FILE,  /* # of pages charged as file rss */
-	MEM_CGROUP_STAT_PGPGIN_COUNT,	/* # of pages paged in */
-	MEM_CGROUP_STAT_PGPGOUT_COUNT,	/* # of pages paged out */
-
-	MEM_CGROUP_STAT_NSTATS,
-};
-
-struct mem_cgroup_stat_cpu {
-	s64 count[MEM_CGROUP_STAT_NSTATS];
-} ____cacheline_aligned_in_smp;
-
-struct mem_cgroup_stat {
-	struct mem_cgroup_stat_cpu cpustat[0];
-};
-
-/*
  * For accounting under irq disable, no need for increment preempt count.
  */
 static inline void __mem_cgroup_stat_add_safe(struct mem_cgroup_stat_cpu *stat,
@@ -106,86 +82,6 @@ static s64 mem_cgroup_local_usage(struct
 	return ret;
 }
 
-/*
- * per-zone information in memory controller.
- */
-struct mem_cgroup_per_zone {
-	/*
-	 * spin_lock to protect the per cgroup LRU
-	 */
-	struct list_head	lists[NR_LRU_LISTS];
-	unsigned long		count[NR_LRU_LISTS];
-
-	struct zone_reclaim_stat reclaim_stat;
-};
-/* Macro for accessing counter */
-#define MEM_CGROUP_ZSTAT(mz, idx)	((mz)->count[(idx)])
-
-struct mem_cgroup_per_node {
-	struct mem_cgroup_per_zone zoneinfo[MAX_NR_ZONES];
-};
-
-struct mem_cgroup_lru_info {
-	struct mem_cgroup_per_node *nodeinfo[MAX_NUMNODES];
-};
-
-/*
- * The memory controller data structure. The memory controller controls both
- * page cache and RSS per cgroup. We would eventually like to provide
- * statistics based on the statistics developed by Rik Van Riel for clock-pro,
- * to help the administrator determine what knobs to tune.
- *
- * TODO: Add a water mark for the memory controller. Reclaim will begin when
- * we hit the water mark. May be even add a low water mark, such that
- * no reclaim occurs from a cgroup at it's low water mark, this is
- * a feature that will be implemented much later in the future.
- */
-struct mem_cgroup {
-	struct cgroup_subsys_state css;
-	/*
-	 * the counter to account for memory usage
-	 */
-	struct res_counter res;
-	/*
-	 * the counter to account for mem+swap usage.
-	 */
-	struct res_counter memsw;
-	/*
-	 * Per cgroup active and inactive list, similar to the
-	 * per zone LRU lists.
-	 */
-	struct mem_cgroup_lru_info info;
-
-	/*
-	  protect against reclaim related member.
-	*/
-	spinlock_t reclaim_param_lock;
-
-	int	prev_priority;	/* for recording reclaim priority */
-
-	/*
-	 * While reclaiming in a hiearchy, we cache the last child we
-	 * reclaimed from.
-	 */
-	int last_scanned_child;
-	/*
-	 * Should the accounting and control be hierarchical, per subtree?
-	 */
-	bool use_hierarchy;
-	unsigned long	last_oom_jiffies;
-	atomic_t	refcnt;
-
-	unsigned int	swappiness;
-
-	/* set when res.limit == memsw.limit */
-	bool		memsw_is_minimum;
-
-	/*
-	 * statistics. This must be placed at the end of memcg.
-	 */
-	struct mem_cgroup_stat stat;
-};
-
 enum charge_type {
 	MEM_CGROUP_CHARGE_TYPE_CACHE = 0,
 	MEM_CGROUP_CHARGE_TYPE_MAPPED,
@@ -244,12 +140,6 @@ static void mem_cgroup_charge_statistics
 }
 
 static struct mem_cgroup_per_zone *
-mem_cgroup_zoneinfo(struct mem_cgroup *mem, int nid, int zid)
-{
-	return &mem->info.nodeinfo[nid]->zoneinfo[zid];
-}
-
-static struct mem_cgroup_per_zone *
 page_cgroup_zoneinfo(struct page_cgroup *pc)
 {
 	struct mem_cgroup *mem = pc->mem_cgroup;
@@ -586,27 +476,6 @@ int mem_cgroup_inactive_file_is_low(stru
 	return (active > inactive);
 }
 
-unsigned long mem_cgroup_zone_nr_pages(struct mem_cgroup *memcg,
-				       struct zone *zone,
-				       enum lru_list lru)
-{
-	int nid = zone->zone_pgdat->node_id;
-	int zid = zone_idx(zone);
-	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
-
-	return MEM_CGROUP_ZSTAT(mz, lru);
-}
-
-struct zone_reclaim_stat *mem_cgroup_get_reclaim_stat(struct mem_cgroup *memcg,
-						      struct zone *zone)
-{
-	int nid = zone->zone_pgdat->node_id;
-	int zid = zone_idx(zone);
-	struct mem_cgroup_per_zone *mz = mem_cgroup_zoneinfo(memcg, nid, zid);
-
-	return &mz->reclaim_stat;
-}
-
 struct zone_reclaim_stat *
 mem_cgroup_get_reclaim_stat_from_page(struct page *page)
 {
--
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