Commit a433658c authored by KOSAKI Motohiro's avatar KOSAKI Motohiro Committed by Linus Torvalds
Browse files

vmscan,memcg: memcg aware swap token 



Currently, memcg reclaim can disable swap token even if the swap token mm
doesn't belong in its memory cgroup.  It's slightly risky.  If an admin
creates very small mem-cgroup and silly guy runs contentious heavy memory
pressure workload, every tasks are going to lose swap token and then
system may become unresponsive.  That's bad.

This patch adds 'memcg' parameter into disable_swap_token().  and if the
parameter doesn't match swap token, VM doesn't disable it.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: default avatarKOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Reviewed-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Reviewed-by: default avatarRik van <Riel&lt;riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e1bbd19b

include/linux/memcontrol.h

+6 −0
Original line number Original line Diff line number Diff line
@@ -84,6 +84,7 @@ int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); 




extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);

extern struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page);

extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);

extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p);

extern struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm);





static inline

static inline

int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)

int mm_match_cgroup(const struct mm_struct *mm, const struct mem_cgroup *cgroup)
@@ -246,6 +247,11 @@ static inline struct mem_cgroup *try_get_mem_cgroup_from_page(struct page *page) 
	return NULL;

	return NULL;

}

}





static inline struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)

{

	return NULL;

}



static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem)

static inline int mm_match_cgroup(struct mm_struct *mm, struct mem_cgroup *mem)

{

{

	return 1;

	return 1;

include/linux/swap.h

+2 −6
Original line number Original line Diff line number Diff line
@@ -358,6 +358,7 @@ struct backing_dev_info; 
extern struct mm_struct *swap_token_mm;

extern struct mm_struct *swap_token_mm;

extern void grab_swap_token(struct mm_struct *);

extern void grab_swap_token(struct mm_struct *);

extern void __put_swap_token(struct mm_struct *);

extern void __put_swap_token(struct mm_struct *);

extern void disable_swap_token(struct mem_cgroup *memcg);





static inline int has_swap_token(struct mm_struct *mm)

static inline int has_swap_token(struct mm_struct *mm)

{

{
@@ -370,11 +371,6 @@ static inline void put_swap_token(struct mm_struct *mm) 
		__put_swap_token(mm);

		__put_swap_token(mm);

}

}





static inline void disable_swap_token(void)

{

	put_swap_token(swap_token_mm);

}



#ifdef CONFIG_CGROUP_MEM_RES_CTLR

#ifdef CONFIG_CGROUP_MEM_RES_CTLR

extern void

extern void

mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);

mem_cgroup_uncharge_swapcache(struct page *page, swp_entry_t ent, bool swapout);
@@ -500,7 +496,7 @@ static inline int has_swap_token(struct mm_struct *mm) 
	return 0;

	return 0;

}

}





static inline void disable_swap_token(void)

static inline void disable_swap_token(struct mem_cgroup *memcg)

{

{

}

}

mm/memcontrol.c

+7 −9
Original line number Original line Diff line number Diff line
@@ -735,7 +735,7 @@ struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) 
				struct mem_cgroup, css);

				struct mem_cgroup, css);

}

}





static struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)

struct mem_cgroup *try_get_mem_cgroup_from_mm(struct mm_struct *mm)

{

{

	struct mem_cgroup *mem = NULL;

	struct mem_cgroup *mem = NULL;
@@ -5414,17 +5414,15 @@ static void mem_cgroup_move_task(struct cgroup_subsys *ss, 
				struct cgroup *old_cont,

				struct cgroup *old_cont,

				struct task_struct *p)

				struct task_struct *p)

{

{

	struct mm_struct *mm;

	struct mm_struct *mm = get_task_mm(p);



	if (!mc.to)

		/* no need to move charge */

		return;





	mm = get_task_mm(p);

	if (mm) {

	if (mm) {

		if (mc.to)

			mem_cgroup_move_charge(mm);

			mem_cgroup_move_charge(mm);

		put_swap_token(mm);

		mmput(mm);

		mmput(mm);

	}

	}

	if (mc.to)

		mem_cgroup_clear_mc();

		mem_cgroup_clear_mc();

}

}

#else	/* !CONFIG_MMU */

#else	/* !CONFIG_MMU */

mm/thrash.c

+68 −19
Original line number Original line Diff line number Diff line
@@ -21,11 +21,31 @@ 
#include <linux/mm.h>

#include <linux/mm.h>

#include <linux/sched.h>

#include <linux/sched.h>

#include <linux/swap.h>

#include <linux/swap.h>

#include <linux/memcontrol.h>





static DEFINE_SPINLOCK(swap_token_lock);

static DEFINE_SPINLOCK(swap_token_lock);

struct mm_struct *swap_token_mm;

struct mm_struct *swap_token_mm;

struct mem_cgroup *swap_token_memcg;

static unsigned int global_faults;

static unsigned int global_faults;





#ifdef CONFIG_CGROUP_MEM_RES_CTLR

static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)

{

	struct mem_cgroup *memcg;



	memcg = try_get_mem_cgroup_from_mm(mm);

	if (memcg)

		css_put(mem_cgroup_css(memcg));



	return memcg;

}

#else

static struct mem_cgroup *swap_token_memcg_from_mm(struct mm_struct *mm)

{

	return NULL;

}

#endif



void grab_swap_token(struct mm_struct *mm)

void grab_swap_token(struct mm_struct *mm)

{

{

	int current_interval;

	int current_interval;
@@ -38,40 +58,69 @@ void grab_swap_token(struct mm_struct *mm) 
		return;

		return;





	/* First come first served */

	/* First come first served */

	if (swap_token_mm == NULL) {

	if (!swap_token_mm)

		mm->token_priority = mm->token_priority + 2;

		goto replace_token;

		swap_token_mm = mm;



	if (mm == swap_token_mm) {

		mm->token_priority += 2;

		goto out;

		goto out;

	}

	}





	if (mm != swap_token_mm) {

	if (current_interval < mm->last_interval)

	if (current_interval < mm->last_interval)

		mm->token_priority++;

		mm->token_priority++;

	else {

	else {

		if (likely(mm->token_priority > 0))

		if (likely(mm->token_priority > 0))

			mm->token_priority--;

			mm->token_priority--;

	}

	}



	/* Check if we deserve the token */

	/* Check if we deserve the token */

		if (mm->token_priority > swap_token_mm->token_priority) {

	if (mm->token_priority > swap_token_mm->token_priority)

			mm->token_priority += 2;

		goto replace_token;

			swap_token_mm = mm;

		}

	} else {

		/* Token holder came in again! */

		mm->token_priority += 2;

	}





out:

out:

	mm->faultstamp = global_faults;

	mm->faultstamp = global_faults;

	mm->last_interval = current_interval;

	mm->last_interval = current_interval;

	spin_unlock(&swap_token_lock);

	spin_unlock(&swap_token_lock);

	return;



replace_token:

	mm->token_priority += 2;

	swap_token_mm = mm;

	swap_token_memcg = swap_token_memcg_from_mm(mm);

	goto out;

}

}





/* Called on process exit. */

/* Called on process exit. */

void __put_swap_token(struct mm_struct *mm)

void __put_swap_token(struct mm_struct *mm)

{

{

	spin_lock(&swap_token_lock);

	spin_lock(&swap_token_lock);

	if (likely(mm == swap_token_mm))

	if (likely(mm == swap_token_mm)) {

		swap_token_mm = NULL;

		swap_token_memcg = NULL;

	}

	spin_unlock(&swap_token_lock);

}



static bool match_memcg(struct mem_cgroup *a, struct mem_cgroup *b)

{

	if (!a)

		return true;

	if (!b)

		return true;

	if (a == b)

		return true;

	return false;

}



void disable_swap_token(struct mem_cgroup *memcg)

{

	/* memcg reclaim don't disable unrelated mm token. */

	if (match_memcg(memcg, swap_token_memcg)) {

		spin_lock(&swap_token_lock);

		if (match_memcg(memcg, swap_token_memcg)) {

			swap_token_mm = NULL;

			swap_token_mm = NULL;

			swap_token_memcg = NULL;

		}

		spin_unlock(&swap_token_lock);

		spin_unlock(&swap_token_lock);

	}

	}

}

mm/vmscan.c

+2 −2
Original line number Original line Diff line number Diff line
@@ -2081,7 +2081,7 @@ static unsigned long do_try_to_free_pages(struct zonelist *zonelist, 
	for (priority = DEF_PRIORITY; priority >= 0; priority--) {

	for (priority = DEF_PRIORITY; priority >= 0; priority--) {

		sc->nr_scanned = 0;

		sc->nr_scanned = 0;

		if (!priority)

		if (!priority)

			disable_swap_token();

			disable_swap_token(sc->mem_cgroup);

		total_scanned += shrink_zones(priority, zonelist, sc);

		total_scanned += shrink_zones(priority, zonelist, sc);

		/*

		/*

		 * Don't shrink slabs when reclaiming memory from

		 * Don't shrink slabs when reclaiming memory from
@@ -2407,7 +2407,7 @@ loop_again: 




		/* The swap token gets in the way of swapout... */

		/* The swap token gets in the way of swapout... */

		if (!priority)

		if (!priority)

			disable_swap_token();

			disable_swap_token(NULL);





		all_zones_ok = 1;

		all_zones_ok = 1;

		balanced = 0;

		balanced = 0;

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