Commit 66e1707b authored by Balbir Singh's avatar Balbir Singh Committed by Linus Torvalds
Browse files

Memory controller: add per cgroup LRU and reclaim 



Add the page_cgroup to the per cgroup LRU.  The reclaim algorithm has
been modified to make the isolate_lru_pages() as a pluggable component.  The
scan_control data structure now accepts the cgroup on behalf of which
reclaims are carried out.  try_to_free_pages() has been extended to become
cgroup aware.

[akpm@linux-foundation.org: fix warning]
[Lee.Schermerhorn@hp.com: initialize all scan_control's isolate_pages member]
[bunk@kernel.org: make do_try_to_free_pages() static]
[hugh@veritas.com: memcgroup: fix try_to_free order]
[kamezawa.hiroyu@jp.fujitsu.com: this unlock_page_cgroup() is unnecessary]
Signed-off-by: default avatarPavel Emelianov <xemul@openvz.org>
Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
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: default avatarLee Schermerhorn <lee.schermerhorn@hp.com>
Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
Signed-off-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 67e465a7

include/linux/memcontrol.h

+12 −0
Original line number Diff line number Diff line
@@ -32,6 +32,13 @@ extern void page_assign_page_cgroup(struct page *page, 
extern struct page_cgroup *page_get_page_cgroup(struct page *page);

extern int mem_cgroup_charge(struct page *page, struct mm_struct *mm);

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,

					struct list_head *dst,

					unsigned long *scanned, int order,

					int mode, struct zone *z,

					struct mem_cgroup *mem_cont,

					int active);



static inline void mem_cgroup_uncharge_page(struct page *page)

{
@@ -71,6 +78,11 @@ static inline void mem_cgroup_uncharge_page(struct page *page) 
{

}



static inline void mem_cgroup_move_lists(struct page_cgroup *pc,

						bool active)

{

}



#endif /* CONFIG_CGROUP_MEM_CONT */



#endif /* _LINUX_MEMCONTROL_H */

include/linux/res_counter.h

+23 −0
Original line number Diff line number Diff line
@@ -99,4 +99,27 @@ int res_counter_charge(struct res_counter *counter, unsigned long val); 
void res_counter_uncharge_locked(struct res_counter *counter, unsigned long val);

void res_counter_uncharge(struct res_counter *counter, unsigned long val);



static inline bool res_counter_limit_check_locked(struct res_counter *cnt)

{

	if (cnt->usage < cnt->limit)

		return true;



	return false;

}



/*

 * Helper function to detect if the cgroup is within it's limit or

 * not. It's currently called from cgroup_rss_prepare()

 */

static inline bool res_counter_check_under_limit(struct res_counter *cnt)

{

	bool ret;

	unsigned long flags;



	spin_lock_irqsave(&cnt->lock, flags);

	ret = res_counter_limit_check_locked(cnt);

	spin_unlock_irqrestore(&cnt->lock, flags);

	return ret;

}



#endif

include/linux/swap.h

+3 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
#include <linux/linkage.h>

#include <linux/mmzone.h>

#include <linux/list.h>

#include <linux/memcontrol.h>

#include <linux/sched.h>



#include <asm/atomic.h>
@@ -182,6 +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 int __isolate_lru_page(struct page *page, int mode);

extern unsigned long shrink_all_memory(unsigned long nr_pages);

extern int vm_swappiness;

extern int remove_mapping(struct address_space *mapping, struct page *page);

mm/memcontrol.c

+143 −5
Original line number Diff line number Diff line
@@ -22,10 +22,15 @@ 
#include <linux/cgroup.h>

#include <linux/mm.h>

#include <linux/page-flags.h>

#include <linux/backing-dev.h>

#include <linux/bit_spinlock.h>

#include <linux/rcupdate.h>

#include <linux/swap.h>

#include <linux/spinlock.h>

#include <linux/fs.h>



struct cgroup_subsys mem_cgroup_subsys;

static const int MEM_CGROUP_RECLAIM_RETRIES = 5;



/*

 * The memory controller data structure. The memory controller controls both
@@ -51,6 +56,10 @@ struct mem_cgroup { 
	 */

	struct list_head active_list;

	struct list_head inactive_list;

	/*

	 * spin_lock to protect the per cgroup LRU

	 */

	spinlock_t lru_lock;

};



/*
@@ -141,6 +150,94 @@ void __always_inline unlock_page_cgroup(struct page *page) 
	bit_spin_unlock(PAGE_CGROUP_LOCK_BIT, &page->page_cgroup);

}



void __mem_cgroup_move_lists(struct page_cgroup *pc, bool active)

{

	if (active)

		list_move(&pc->lru, &pc->mem_cgroup->active_list);

	else

		list_move(&pc->lru, &pc->mem_cgroup->inactive_list);

}



/*

 * This routine assumes that the appropriate zone's lru lock is already held

 */

void mem_cgroup_move_lists(struct page_cgroup *pc, bool active)

{

	struct mem_cgroup *mem;

	if (!pc)

		return;



	mem = pc->mem_cgroup;



	spin_lock(&mem->lru_lock);

	__mem_cgroup_move_lists(pc, active);

	spin_unlock(&mem->lru_lock);

}



unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan,

					struct list_head *dst,

					unsigned long *scanned, int order,

					int mode, struct zone *z,

					struct mem_cgroup *mem_cont,

					int active)

{

	unsigned long nr_taken = 0;

	struct page *page;

	unsigned long scan;

	LIST_HEAD(pc_list);

	struct list_head *src;

	struct page_cgroup *pc;



	if (active)

		src = &mem_cont->active_list;

	else

		src = &mem_cont->inactive_list;



	spin_lock(&mem_cont->lru_lock);

	for (scan = 0; scan < nr_to_scan && !list_empty(src); scan++) {

		pc = list_entry(src->prev, struct page_cgroup, lru);

		page = pc->page;

		VM_BUG_ON(!pc);



		if (PageActive(page) && !active) {

			__mem_cgroup_move_lists(pc, true);

			scan--;

			continue;

		}

		if (!PageActive(page) && active) {

			__mem_cgroup_move_lists(pc, false);

			scan--;

			continue;

		}



		/*

		 * Reclaim, per zone

		 * TODO: make the active/inactive lists per zone

		 */

		if (page_zone(page) != z)

			continue;



		/*

		 * Check if the meta page went away from under us

		 */

		if (!list_empty(&pc->lru))

			list_move(&pc->lru, &pc_list);

		else

			continue;



		if (__isolate_lru_page(page, mode) == 0) {

			list_move(&page->lru, dst);

			nr_taken++;

		}

	}



	list_splice(&pc_list, src);

	spin_unlock(&mem_cont->lru_lock);



	*scanned = scan;

	return nr_taken;

}



/*

 * Charge the memory controller for page usage.

 * Return
@@ -151,6 +248,8 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm) 
{

	struct mem_cgroup *mem;

	struct page_cgroup *pc, *race_pc;

	unsigned long flags;

	unsigned long nr_retries = MEM_CGROUP_RECLAIM_RETRIES;



	/*

	 * Should page_cgroup's go to their own slab?
@@ -159,13 +258,19 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm) 
	 * to see if the cgroup page already has a page_cgroup associated

	 * with it

	 */

retry:

	lock_page_cgroup(page);

	pc = page_get_page_cgroup(page);

	/*

	 * The page_cgroup exists and the page has already been accounted

	 */

	if (pc) {

		atomic_inc(&pc->ref_cnt);

		if (unlikely(!atomic_inc_not_zero(&pc->ref_cnt))) {

			/* this page is under being uncharged ? */

			unlock_page_cgroup(page);

			cpu_relax();

			goto retry;

		} else

			goto done;

	}
@@ -197,7 +302,32 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm) 
	 * If we created the page_cgroup, we should free it on exceeding

	 * the cgroup limit.

	 */

	if (res_counter_charge(&mem->res, 1)) {

	while (res_counter_charge(&mem->res, 1)) {

		if (try_to_free_mem_cgroup_pages(mem))

			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;

			/*

			 * Since we control both RSS and cache, we end up with a

			 * very interesting scenario where we end up reclaiming

			 * memory (essentially RSS), since the memory is pushed

			 * to swap cache, we eventually end up adding those

			 * pages back to our list. Hence we give ourselves a

			 * few chances before we fail

			 */

		else if (nr_retries--) {

			congestion_wait(WRITE, HZ/10);

			continue;

		}



		css_put(&mem->css);

		goto free_pc;

	}
@@ -221,14 +351,16 @@ int mem_cgroup_charge(struct page *page, struct mm_struct *mm) 
	pc->page = page;

	page_assign_page_cgroup(page, pc);



	spin_lock_irqsave(&mem->lru_lock, flags);

	list_add(&pc->lru, &mem->active_list);

	spin_unlock_irqrestore(&mem->lru_lock, flags);



done:

	unlock_page_cgroup(page);

	return 0;

free_pc:

	kfree(pc);

	return -ENOMEM;

err:

	unlock_page_cgroup(page);

	return -ENOMEM;

}
@@ -240,6 +372,7 @@ void mem_cgroup_uncharge(struct page_cgroup *pc) 
{

	struct mem_cgroup *mem;

	struct page *page;

	unsigned long flags;



	if (!pc)

		return;
@@ -252,6 +385,10 @@ void mem_cgroup_uncharge(struct page_cgroup *pc) 
		page_assign_page_cgroup(page, NULL);

		unlock_page_cgroup(page);

		res_counter_uncharge(&mem->res, 1);



 		spin_lock_irqsave(&mem->lru_lock, flags);

 		list_del_init(&pc->lru);

 		spin_unlock_irqrestore(&mem->lru_lock, flags);

		kfree(pc);

	}

}
@@ -310,6 +447,7 @@ mem_cgroup_create(struct cgroup_subsys *ss, struct cgroup *cont) 
	res_counter_init(&mem->res);

	INIT_LIST_HEAD(&mem->active_list);

	INIT_LIST_HEAD(&mem->inactive_list);

	spin_lock_init(&mem->lru_lock);

	return &mem->css;

}

mm/swap.c

+2 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ 
#include <linux/cpu.h>

#include <linux/notifier.h>

#include <linux/backing-dev.h>

#include <linux/memcontrol.h>



/* How many pages do we try to swap or page in/out together? */

int page_cluster;
@@ -175,6 +176,7 @@ void activate_page(struct page *page) 
		SetPageActive(page);

		add_page_to_active_list(zone, page);

		__count_vm_event(PGACTIVATE);

		mem_cgroup_move_lists(page_get_page_cgroup(page), true);

	}

	spin_unlock_irq(&zone->lru_lock);

}

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