Messages in this thread | | | Date | Wed, 1 Oct 2008 09:38:04 -0700 | From | Randy Dunlap <> | Subject | Re: [PATCH 4/6] memcg: new force_empty and move_account |
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On Wed, 1 Oct 2008 16:59:12 +0900 KAMEZAWA Hiroyuki wrote:
> Documentation/controllers/memory.txt | 10 - > mm/memcontrol.c | 267 +++++++++++++++++++++++++++-------- > 2 files changed, 216 insertions(+), 61 deletions(-) > > Index: mmotm-2.6.27-rc7+/mm/memcontrol.c > =================================================================== > --- mmotm-2.6.27-rc7+.orig/mm/memcontrol.c > +++ mmotm-2.6.27-rc7+/mm/memcontrol.c > @@ -538,6 +533,24 @@ nomem: > return -ENOMEM; > } > > +/** > + * mem_cgroup_try_charge - get charge of PAGE_SIZE. > + * @mm: an mm_struct which is charged against. (when *memcg is NULL) > + * @gfp_mask: gfp_mask for reclaim. > + * @memcg: a pointer to memory cgroup which is charged against. > + * > + * charge aginst memory cgroup pointed by *memcg. if *memcg == NULL, estimated > + * memory cgroup from @mm is got and stored in *memcg. > + * > + * Retruns 0 if success. -ENOMEM at failure. > + */ > + > +int mem_cgroup_try_charge(struct mm_struct *mm, > + gfp_t mask, struct mem_cgroup **memcg) > +{ > + return __mem_cgroup_try_charge(mm, mask, memcg, false); > +} > + > /* > * commit a charge got by mem_cgroup_try_charge() and makes page_cgroup to be > * USED state. If already USED, uncharge and return. > @@ -567,11 +580,109 @@ static void __mem_cgroup_commit_charge(s > mz = page_cgroup_zoneinfo(pc); > > spin_lock_irqsave(&mz->lru_lock, flags); > - __mem_cgroup_add_list(mz, pc); > + __mem_cgroup_add_list(mz, pc, true); > spin_unlock_irqrestore(&mz->lru_lock, flags); > unlock_page_cgroup(pc); > } > > +/** > + * mem_cgroup_move_account - move account of the page > + * @pc ... page_cgroup of the page. > + * @from ... mem_cgroup which the page is moved from. > + * @to ... mem_cgroup which the page is moved to. @from != @to.
Bad kernel-doc format. Use (e.g.) * @pc: page_cgroup of the page
as was done in the function above.
> + * > + * The caller must confirm following. > + * 1. disable irq. > + * 2. lru_lock of old mem_cgroup(@from) should be held. > + * > + * returns 0 at success, > + * returns -EBUSY when lock is busy or "pc" is unstable. > + * > + * This function do "uncharge" from old cgroup but doesn't do "charge" to
does
> + * new cgroup. It should be done by a caller. > + */ > + > +static int mem_cgroup_move_account(struct page_cgroup *pc, > + struct mem_cgroup *from, struct mem_cgroup *to) > +{ ... > +} > + > Index: mmotm-2.6.27-rc7+/Documentation/controllers/memory.txt > =================================================================== > --- mmotm-2.6.27-rc7+.orig/Documentation/controllers/memory.txt > +++ mmotm-2.6.27-rc7+/Documentation/controllers/memory.txt > @@ -211,7 +211,9 @@ The memory.force_empty gives an interfac > > # echo 1 > memory.force_empty > > -will drop all charges in cgroup. Currently, this is maintained for test. > +Will move account to parent. if parenet is full, will try to free pages.
If parent
> +If both of a parent and a child are busy, return -EBUSY;
maybe: If both parent and child are busy, return -EBUSY.
> +This file, memory.force_empty, is just for debug purpose. > > 4. Testing > > @@ -242,8 +244,10 @@ reclaimed. > > A cgroup can be removed by rmdir, but as discussed in sections 4.1 and 4.2, a > cgroup might have some charge associated with it, even though all > -tasks have migrated away from it. Such charges are automatically dropped at > -rmdir() if there are no tasks. > +tasks have migrated away from it. > +Such charges are moved to its parent as mush as possible and freed if parent
much
> +seems to be full. (see force_empty)
seems?? Is it questionable/unsure?
> +If both of them are busy, rmdir() returns -EBUSY. > > 5. TODO
--- ~Randy
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