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Commit cf475ad2 authored by Balbir Singh's avatar Balbir Singh Committed by Linus Torvalds
Browse files

cgroups: add an owner to the mm_struct 



Remove the mem_cgroup member from mm_struct and instead adds an owner.

This approach was suggested by Paul Menage.  The advantage of this approach
is that, once the mm->owner is known, using the subsystem id, the cgroup
can be determined.  It also allows several control groups that are
virtually grouped by mm_struct, to exist independent of the memory
controller i.e., without adding mem_cgroup's for each controller, to
mm_struct.

A new config option CONFIG_MM_OWNER is added and the memory resource
controller selects this config option.

This patch also adds cgroup callbacks to notify subsystems when mm->owner
changes.  The mm_cgroup_changed callback is called with the task_lock() of
the new task held and is called just prior to changing the mm->owner.

I am indebted to Paul Menage for the several reviews of this patchset and
helping me make it lighter and simpler.

This patch was tested on a powerpc box, it was compiled with both the
MM_OWNER config turned on and off.

After the thread group leader exits, it's moved to init_css_state by
cgroup_exit(), thus all future charges from runnings threads would be
redirected to the init_css_set's subsystem.

Signed-off-by: default avatarBalbir Singh <balbir@linux.vnet.ibm.com>
Cc: Pavel Emelianov <xemul@openvz.org>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Sudhir Kumar <skumar@linux.vnet.ibm.com>
Cc: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Cc: Hirokazu Takahashi <taka@valinux.co.jp>
Cc: David Rientjes <rientjes@google.com>,
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Acked-by: default avatarKAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Reviewed-by: default avatarPaul Menage <menage@google.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 29486df3

fs/exec.c

+1 −0
Original line number Diff line number Diff line
@@ -735,6 +735,7 @@ static int exec_mmap(struct mm_struct *mm) 
	tsk->active_mm = mm;

	activate_mm(active_mm, mm);

	task_unlock(tsk);

	mm_update_next_owner(mm);

	arch_pick_mmap_layout(mm);

	if (old_mm) {

		up_read(&old_mm->mmap_sem);

include/linux/cgroup.h

+15 −0
Original line number Diff line number Diff line
@@ -305,6 +305,12 @@ struct cgroup_subsys { 
			struct cgroup *cgrp);

	void (*post_clone)(struct cgroup_subsys *ss, struct cgroup *cgrp);

	void (*bind)(struct cgroup_subsys *ss, struct cgroup *root);

	/*

	 * This routine is called with the task_lock of mm->owner held

	 */

	void (*mm_owner_changed)(struct cgroup_subsys *ss,

					struct cgroup *old,

					struct cgroup *new);

	int subsys_id;

	int active;

	int disabled;
@@ -390,4 +396,13 @@ static inline int cgroupstats_build(struct cgroupstats *stats, 


#endif /* !CONFIG_CGROUPS */



#ifdef CONFIG_MM_OWNER

extern void

cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new);

#else /* !CONFIG_MM_OWNER */

static inline void

cgroup_mm_owner_callbacks(struct task_struct *old, struct task_struct *new)

{

}

#endif /* CONFIG_MM_OWNER */

#endif /* _LINUX_CGROUP_H */

include/linux/memcontrol.h

+3 −13
Original line number Diff line number Diff line
@@ -27,9 +27,6 @@ struct mm_struct; 


#ifdef CONFIG_CGROUP_MEM_RES_CTLR



extern void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p);

extern void mm_free_cgroup(struct mm_struct *mm);



#define page_reset_bad_cgroup(page)	((page)->page_cgroup = 0)



extern struct page_cgroup *page_get_page_cgroup(struct page *page);
@@ -48,8 +45,10 @@ extern unsigned long mem_cgroup_isolate_pages(unsigned long nr_to_scan, 
extern void mem_cgroup_out_of_memory(struct mem_cgroup *mem, gfp_t gfp_mask);

int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem);



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



#define mm_match_cgroup(mm, cgroup)	\

	((cgroup) == rcu_dereference((mm)->mem_cgroup))

	((cgroup) == mem_cgroup_from_task((mm)->owner))



extern int mem_cgroup_prepare_migration(struct page *page);

extern void mem_cgroup_end_migration(struct page *page);
@@ -73,15 +72,6 @@ extern long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem, 
				struct zone *zone, int priority);



#else /* CONFIG_CGROUP_MEM_RES_CTLR */

static inline void mm_init_cgroup(struct mm_struct *mm,

					struct task_struct *p)

{

}



static inline void mm_free_cgroup(struct mm_struct *mm)

{

}



static inline void page_reset_bad_cgroup(struct page *page)

{

}

include/linux/mm_types.h

+3 −2
Original line number Diff line number Diff line
@@ -225,8 +225,9 @@ struct mm_struct { 
	/* aio bits */

	rwlock_t		ioctx_list_lock;	/* aio lock */

	struct kioctx		*ioctx_list;

#ifdef CONFIG_CGROUP_MEM_RES_CTLR

	struct mem_cgroup *mem_cgroup;

#ifdef CONFIG_MM_OWNER

	struct task_struct *owner;	/* The thread group leader that */

					/* owns the mm_struct.		*/

#endif

};

include/linux/sched.h

+13 −0
Original line number Diff line number Diff line
@@ -2148,6 +2148,19 @@ static inline void migration_init(void) 
#define TASK_SIZE_OF(tsk)	TASK_SIZE

#endif



#ifdef CONFIG_MM_OWNER

extern void mm_update_next_owner(struct mm_struct *mm);

extern void mm_init_owner(struct mm_struct *mm, struct task_struct *p);

#else

static inline void mm_update_next_owner(struct mm_struct *mm)

{

}



static inline void mm_init_owner(struct mm_struct *mm, struct task_struct *p)

{

}

#endif /* CONFIG_MM_OWNER */



#endif /* __KERNEL__ */



#endif