Messages in this thread | | | Date | Tue, 25 Mar 2008 09:26:37 +0800 | From | Li Zefan <> | Subject | Re: [RFC][-mm] Memory controller add mm->owner |
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Balbir Singh wrote: > This patch removes 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. > > The code initially assigns mm->owner to the task and then after the > thread group leader is identified. The mm->owner is changed to the thread > group leader of the task later at the end of copy_process. > > Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com> > --- > > include/linux/memcontrol.h | 14 +++++++++++++- > include/linux/mm_types.h | 5 ++++- > kernel/fork.c | 4 ++++ > mm/memcontrol.c | 42 ++++++++++++++++++++++++++++++++++-------- > 4 files changed, 55 insertions(+), 10 deletions(-) > > diff -puN include/linux/mm_types.h~memory-controller-add-mm-owner include/linux/mm_types.h > --- linux-2.6.25-rc5/include/linux/mm_types.h~memory-controller-add-mm-owner 2008-03-20 13:35:09.000000000 +0530 > +++ linux-2.6.25-rc5-balbir/include/linux/mm_types.h 2008-03-20 15:11:05.000000000 +0530 > @@ -228,7 +228,10 @@ struct mm_struct { > rwlock_t ioctx_list_lock; > struct kioctx *ioctx_list; > #ifdef CONFIG_CGROUP_MEM_RES_CTLR > - struct mem_cgroup *mem_cgroup; > + struct task_struct *owner; /* The thread group leader that */ > + /* owns the mm_struct. This */ > + /* might be useful even outside */ > + /* of the config option */ > #endif > > #ifdef CONFIG_PROC_FS > diff -puN kernel/fork.c~memory-controller-add-mm-owner kernel/fork.c > --- linux-2.6.25-rc5/kernel/fork.c~memory-controller-add-mm-owner 2008-03-20 13:35:09.000000000 +0530 > +++ linux-2.6.25-rc5-balbir/kernel/fork.c 2008-03-24 18:49:29.000000000 +0530 > @@ -1357,6 +1357,10 @@ static struct task_struct *copy_process( > write_unlock_irq(&tasklist_lock); > proc_fork_connector(p); > cgroup_post_fork(p); > + > + if (!(clone_flags & CLONE_VM)) > + mem_cgroup_fork_init(p); > + > return p; > > bad_fork_free_pid: > diff -puN include/linux/memcontrol.h~memory-controller-add-mm-owner include/linux/memcontrol.h > --- linux-2.6.25-rc5/include/linux/memcontrol.h~memory-controller-add-mm-owner 2008-03-20 13:35:09.000000000 +0530 > +++ linux-2.6.25-rc5-balbir/include/linux/memcontrol.h 2008-03-24 18:49:52.000000000 +0530 > @@ -29,6 +29,7 @@ struct mm_struct; > > extern void mm_init_cgroup(struct mm_struct *mm, struct task_struct *p); > extern void mm_free_cgroup(struct mm_struct *mm); > +extern void mem_cgroup_fork_init(struct task_struct *p); > > #define page_reset_bad_cgroup(page) ((page)->page_cgroup = 0) > > @@ -49,7 +50,7 @@ extern void mem_cgroup_out_of_memory(str > int task_in_mem_cgroup(struct task_struct *task, const struct mem_cgroup *mem); > > #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); > @@ -72,6 +73,8 @@ extern long mem_cgroup_calc_reclaim_acti > extern long mem_cgroup_calc_reclaim_inactive(struct mem_cgroup *mem, > struct zone *zone, int priority); > > +extern struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p); > + > #else /* CONFIG_CGROUP_MEM_RES_CTLR */ > static inline void mm_init_cgroup(struct mm_struct *mm, > struct task_struct *p) > @@ -82,6 +85,10 @@ static inline void mm_free_cgroup(struct > { > } > > +static inline void mem_cgroup_fork_init(struct task_struct *p) > +{ > +} > + > static inline void page_reset_bad_cgroup(struct page *page) > { > } > @@ -172,6 +179,11 @@ static inline long mem_cgroup_calc_recla > { > return 0; > } > + > +static void mm_free_fork_cgroup(struct task_struct *p) > +{ > +} > +
Where is this function used? I don't see the corresponding one with CONFIG_CGROUP_MEM_RES_CTLR enabled?
> #endif /* CONFIG_CGROUP_MEM_CONT */ > > #endif /* _LINUX_MEMCONTROL_H */ > diff -puN mm/memcontrol.c~memory-controller-add-mm-owner mm/memcontrol.c > --- linux-2.6.25-rc5/mm/memcontrol.c~memory-controller-add-mm-owner 2008-03-20 13:35:09.000000000 +0530 > +++ linux-2.6.25-rc5-balbir/mm/memcontrol.c 2008-03-24 19:04:32.000000000 +0530 > @@ -236,7 +236,7 @@ static struct mem_cgroup *mem_cgroup_fro > css); > } > > -static struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) > +struct mem_cgroup *mem_cgroup_from_task(struct task_struct *p) > { > return container_of(task_subsys_state(p, mem_cgroup_subsys_id), > struct mem_cgroup, css); > @@ -248,12 +248,40 @@ void mm_init_cgroup(struct mm_struct *mm > > mem = mem_cgroup_from_task(p); > css_get(&mem->css); > - mm->mem_cgroup = mem; > + mm->owner = p; > +} > + > +void mem_cgroup_fork_init(struct task_struct *p) > +{ > + struct mm_struct *mm = get_task_mm(p); > + struct mem_cgroup *mem, *oldmem;
Leave an empty line here.
> + if (!mm) > + return; > + > + /* > + * Initial owner at mm_init_cgroup() time is the task itself. > + * The thread group leader had not been setup then > + */ > + oldmem = mem_cgroup_from_task(mm->owner); > + /* > + * Override the mm->owner after we know the thread group later > + */ > + mm->owner = p->group_leader; > + mem = mem_cgroup_from_task(mm->owner); > + css_get(&mem->css); > + css_put(&oldmem->css); > + mmput(mm); > } > > void mm_free_cgroup(struct mm_struct *mm) > { > - css_put(&mm->mem_cgroup->css); > + struct mem_cgroup *mem; > + > + /* > + * TODO: Should we assign mm->owner to NULL here? > + */ > + mem = mem_cgroup_from_task(mm->owner); > + css_put(&mem->css); > } > > static inline int page_cgroup_locked(struct page *page) > @@ -476,6 +504,7 @@ unsigned long mem_cgroup_isolate_pages(u > int zid = zone_idx(z); > struct mem_cgroup_per_zone *mz; > > + BUG_ON(!mem_cont); > mz = mem_cgroup_zoneinfo(mem_cont, nid, zid); > if (active) > src = &mz->active_list; > @@ -573,13 +602,11 @@ retry: > if (!mm) > mm = &init_mm; > > - rcu_read_lock(); > - mem = rcu_dereference(mm->mem_cgroup); > + mem = mem_cgroup_from_task(mm->owner); > /* > * For every charge from the cgroup, increment reference count > */ > css_get(&mem->css); > - rcu_read_unlock(); > > while (res_counter_charge(&mem->res, PAGE_SIZE)) { > if (!(gfp_mask & __GFP_WAIT)) > @@ -988,7 +1015,7 @@ mem_cgroup_create(struct cgroup_subsys * > > if (unlikely((cont->parent) == NULL)) { > mem = &init_mem_cgroup; > - init_mm.mem_cgroup = mem; > + init_mm.owner = &init_task; > } else > mem = kzalloc(sizeof(struct mem_cgroup), GFP_KERNEL); > > @@ -1069,7 +1096,6 @@ static void mem_cgroup_move_task(struct > goto out; > > css_get(&mem->css); > - rcu_assign_pointer(mm->mem_cgroup, mem); > css_put(&old_mem->css); > > out: > _ >
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