Re: [PATCH 36 of 66] memcg compound

KAMEZAWA Hiroyuki
2010-11-19T01:16:39Z

On Thu, 18 Nov 2010 15:26:28 +0000
Mel Gorman <mel@csn.ul.ie> wrote:

> On Wed, Nov 03, 2010 at 04:28:11PM +0100, Andrea Arcangeli wrote:
> > From: Andrea Arcangeli <aarcange@redhat.com>
> >
> > Teach memcg to charge/uncharge compound pages.
> >
> > Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
> > Acked-by: Rik van Riel <riel@redhat.com>
> > ---
> >
> > diff --git a/mm/memcontrol.c b/mm/memcontrol.c
> > --- a/mm/memcontrol.c
> > +++ b/mm/memcontrol.c
> > @@ -1019,6 +1019,10 @@ mem_cgroup_get_reclaim_stat_from_page(st
> > {
> > struct page_cgroup *pc;
> > struct mem_cgroup_per_zone *mz;
> > + int page_size = PAGE_SIZE;
> > +
> > + if (PageTransHuge(page))
> > + page_size <<= compound_order(page);
> >
> > if (mem_cgroup_disabled())
> > return NULL;
> > @@ -1879,12 +1883,14 @@ static int __mem_cgroup_do_charge(struct
> > * oom-killer can be invoked.
> > */
> > static int __mem_cgroup_try_charge(struct mm_struct *mm,
> > - gfp_t gfp_mask, struct mem_cgroup **memcg, bool oom)
> > + gfp_t gfp_mask,
> > + struct mem_cgroup **memcg, bool oom,
> > + int page_size)
>
> Any concerns about page_size overflowing int? ppc64 has 16G pages for example
> although it will never be in this path. hmm, I see that charge size is already
> int so maybe this is more of a memcg issue than it is THP but hugetlbfs
> treats page sizes as unsigned long. For example see vma_kernel_pagesize()
>

If there are requirements of big page > 4GB, unsigned long should be used.

>
> > {
> > int nr_oom_retries = MEM_CGROUP_RECLAIM_RETRIES;
> > struct mem_cgroup *mem = NULL;
> > int ret;
> > - int csize = CHARGE_SIZE;
> > + int csize = max(CHARGE_SIZE, (unsigned long) page_size);
> >

unsigned long here.

> > /*
> > * Unlike gloval-vm's OOM-kill, we're not in memory shortage
> > @@ -1909,7 +1915,7 @@ again:
> > VM_BUG_ON(css_is_removed(&mem->css));
> > if (mem_cgroup_is_root(mem))
> > goto done;
> > - if (consume_stock(mem))
> > + if (page_size == PAGE_SIZE && consume_stock(mem))
> > goto done;
> > css_get(&mem->css);
> > } else {
> > @@ -1933,7 +1939,7 @@ again:
> > rcu_read_unlock();
> > goto done;
> > }
> > - if (consume_stock(mem)) {
> > + if (page_size == PAGE_SIZE && consume_stock(mem)) {
> > /*
> > * It seems dagerous to access memcg without css_get().
> > * But considering how consume_stok works, it's not
> > @@ -1974,7 +1980,7 @@ again:
> > case CHARGE_OK:
> > break;
> > case CHARGE_RETRY: /* not in OOM situation but retry */
> > - csize = PAGE_SIZE;
> > + csize = page_size;
> > css_put(&mem->css);
> > mem = NULL;
> > goto again;
> > @@ -1995,8 +2001,8 @@ again:
> > }
> > } while (ret != CHARGE_OK);
> >
> > - if (csize > PAGE_SIZE)
> > - refill_stock(mem, csize - PAGE_SIZE);
> > + if (csize > page_size)
> > + refill_stock(mem, csize - page_size);
> > css_put(&mem->css);
> > done:
> > *memcg = mem;
> > @@ -2024,9 +2030,10 @@ static void __mem_cgroup_cancel_charge(s
> > }
> > }
> >
> > -static void mem_cgroup_cancel_charge(struct mem_cgroup *mem)
> > +static void mem_cgroup_cancel_charge(struct mem_cgroup *mem,
> > + int page_size)
> > {
> > - __mem_cgroup_cancel_charge(mem, 1);
> > + __mem_cgroup_cancel_charge(mem, page_size >> PAGE_SHIFT);
> > }
> >
> > /*
> > @@ -2082,8 +2089,9 @@ struct mem_cgroup *try_get_mem_cgroup_fr
> > */
> >
> > static void __mem_cgroup_commit_charge(struct mem_cgroup *mem,
> > - struct page_cgroup *pc,
> > - enum charge_type ctype)
> > + struct page_cgroup *pc,
> > + enum charge_type ctype,
> > + int page_size)
> > {
> > /* try_charge() can return NULL to *memcg, taking care of it. */
> > if (!mem)
> > @@ -2092,7 +2100,7 @@ static void __mem_cgroup_commit_charge(s
> > lock_page_cgroup(pc);
> > if (unlikely(PageCgroupUsed(pc))) {
> > unlock_page_cgroup(pc);
> > - mem_cgroup_cancel_charge(mem);
> > + mem_cgroup_cancel_charge(mem, page_size);
> > return;
> > }
> >
> > @@ -2166,7 +2174,7 @@ static void __mem_cgroup_move_account(st
> > mem_cgroup_charge_statistics(from, pc, false);
> > if (uncharge)
> > /* This is not "cancel", but cancel_charge does all we need. */
> > - mem_cgroup_cancel_charge(from);
> > + mem_cgroup_cancel_charge(from, PAGE_SIZE);
> >
> > /* caller should have done css_get */
> > pc->mem_cgroup = to;
> > @@ -2227,13 +2235,14 @@ static int mem_cgroup_move_parent(struct
> > goto put;
> >
> > parent = mem_cgroup_from_cont(pcg);
> > - ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false);
> > + ret = __mem_cgroup_try_charge(NULL, gfp_mask, &parent, false,
> > + PAGE_SIZE);
> > if (ret || !parent)
> > goto put_back;
> >
> > ret = mem_cgroup_move_account(pc, child, parent, true);
> > if (ret)
> > - mem_cgroup_cancel_charge(parent);
> > + mem_cgroup_cancel_charge(parent, PAGE_SIZE);
> > put_back:
> > putback_lru_page(page);
> > put:
> > @@ -2254,6 +2263,10 @@ static int mem_cgroup_charge_common(stru
> > struct mem_cgroup *mem = NULL;
> > struct page_cgroup *pc;
> > int ret;
> > + int page_size = PAGE_SIZE;
> > +
> > + if (PageTransHuge(page))
> > + page_size <<= compound_order(page);
> >
> > pc = lookup_page_cgroup(page);
> > /* can happen at boot */
> > @@ -2261,11 +2274,11 @@ static int mem_cgroup_charge_common(stru
> > return 0;
> > prefetchw(pc);
> >
> > - ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true);
> > + ret = __mem_cgroup_try_charge(mm, gfp_mask, &mem, true, page_size);
> > if (ret || !mem)
> > return ret;
> >
> > - __mem_cgroup_commit_charge(mem, pc, ctype);
> > + __mem_cgroup_commit_charge(mem, pc, ctype, page_size);
> > return 0;
> > }
> >
> > @@ -2274,8 +2287,6 @@ int mem_cgroup_newpage_charge(struct pag
> > {
> > if (mem_cgroup_disabled())
> > return 0;
> > - if (PageCompound(page))
> > - return 0;
> > /*
> > * If already mapped, we don't have to account.
> > * If page cache, page->mapping has address_space.
> > @@ -2381,13 +2392,13 @@ int mem_cgroup_try_charge_swapin(struct
> > if (!mem)
> > goto charge_cur_mm;
> > *ptr = mem;
> > - ret = __mem_cgroup_try_charge(NULL, mask, ptr, true);
> > + ret = __mem_cgroup_try_charge(NULL, mask, ptr, true, PAGE_SIZE);
> > css_put(&mem->css);
> > return ret;
> > charge_cur_mm:
> > if (unlikely(!mm))
> > mm = &init_mm;
> > - return __mem_cgroup_try_charge(mm, mask, ptr, true);
> > + return __mem_cgroup_try_charge(mm, mask, ptr, true, PAGE_SIZE);
> > }
> >
> > static void
> > @@ -2403,7 +2414,7 @@ __mem_cgroup_commit_charge_swapin(struct
> > cgroup_exclude_rmdir(&ptr->css);
> > pc = lookup_page_cgroup(page);
> > mem_cgroup_lru_del_before_commit_swapcache(page);
> > - __mem_cgroup_commit_charge(ptr, pc, ctype);
> > + __mem_cgroup_commit_charge(ptr, pc, ctype, PAGE_SIZE);
> > mem_cgroup_lru_add_after_commit_swapcache(page);
> > /*
> > * Now swap is on-memory. This means this page may be
> > @@ -2452,11 +2463,12 @@ void mem_cgroup_cancel_charge_swapin(str
> > return;
> > if (!mem)
> > return;
> > - mem_cgroup_cancel_charge(mem);
> > + mem_cgroup_cancel_charge(mem, PAGE_SIZE);
> > }
> >
> > static void
> > -__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype)
> > +__do_uncharge(struct mem_cgroup *mem, const enum charge_type ctype,
> > + int page_size)
> > {
> > struct memcg_batch_info *batch = NULL;
> > bool uncharge_memsw = true;
> > @@ -2491,14 +2503,14 @@ __do_uncharge(struct mem_cgroup *mem, co
> > if (batch->memcg != mem)
> > goto direct_uncharge;
> > /* remember freed charge and uncharge it later */
> > - batch->bytes += PAGE_SIZE;
> > + batch->bytes += page_size;

Hmm, isn't it simpler to avoid batched-uncharge when page_size > PAGE_SIZE ?

> > if (uncharge_memsw)
> > - batch->memsw_bytes += PAGE_SIZE;
> > + batch->memsw_bytes += page_size;
> > return;
> > direct_uncharge:
> > - res_counter_uncharge(&mem->res, PAGE_SIZE);
> > + res_counter_uncharge(&mem->res, page_size);
> > if (uncharge_memsw)
> > - res_counter_uncharge(&mem->memsw, PAGE_SIZE);
> > + res_counter_uncharge(&mem->memsw, page_size);
> > if (unlikely(batch->memcg != mem))
> > memcg_oom_recover(mem);
> > return;
> > @@ -2512,6 +2524,7 @@ __mem_cgroup_uncharge_common(struct page
> > {
> > struct page_cgroup *pc;
> > struct mem_cgroup *mem = NULL;
> > + int page_size = PAGE_SIZE;
> >
> > if (mem_cgroup_disabled())
> > return NULL;
> > @@ -2519,6 +2532,9 @@ __mem_cgroup_uncharge_common(struct page
> > if (PageSwapCache(page))
> > return NULL;
> >
> > + if (PageTransHuge(page))
> > + page_size <<= compound_order(page);
> > +
> > /*
> > * Check if our page_cgroup is valid
> > */
> > @@ -2572,7 +2588,7 @@ __mem_cgroup_uncharge_common(struct page
> > mem_cgroup_get(mem);
> > }
> > if (!mem_cgroup_is_root(mem))
> > - __do_uncharge(mem, ctype);
> > + __do_uncharge(mem, ctype, page_size);
> >
> > return mem;
> >
> > @@ -2767,6 +2783,7 @@ int mem_cgroup_prepare_migration(struct
> > enum charge_type ctype;
> > int ret = 0;
> >
> > + VM_BUG_ON(PageTransHuge(page));
> > if (mem_cgroup_disabled())
> > return 0;
> >
> > @@ -2816,7 +2833,7 @@ int mem_cgroup_prepare_migration(struct
> > return 0;
> >
> > *ptr = mem;
> > - ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false);
> > + ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, ptr, false, PAGE_SIZE);
> > css_put(&mem->css);/* drop extra refcnt */
> > if (ret || *ptr == NULL) {
> > if (PageAnon(page)) {
> > @@ -2843,7 +2860,7 @@ int mem_cgroup_prepare_migration(struct
> > ctype = MEM_CGROUP_CHARGE_TYPE_CACHE;
> > else
> > ctype = MEM_CGROUP_CHARGE_TYPE_SHMEM;
> > - __mem_cgroup_commit_charge(mem, pc, ctype);
> > + __mem_cgroup_commit_charge(mem, pc, ctype, PAGE_SIZE);
> > return ret;
> > }
> >
> > @@ -4452,7 +4469,8 @@ one_by_one:
> > batch_count = PRECHARGE_COUNT_AT_ONCE;
> > cond_resched();
> > }
> > - ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false);
> > + ret = __mem_cgroup_try_charge(NULL, GFP_KERNEL, &mem, false,
> > + PAGE_SIZE);
> > if (ret || !mem)
> > /* mem_cgroup_clear_mc() will do uncharge later */
> > return -ENOMEM;
> > @@ -4614,6 +4632,7 @@ static int mem_cgroup_count_precharge_pt
> > pte_t *pte;
> > spinlock_t *ptl;
> >
> > + VM_BUG_ON(pmd_trans_huge(*pmd));
> > pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
> > for (; addr != end; pte++, addr += PAGE_SIZE)
> > if (is_target_pte_for_mc(vma, addr, *pte, NULL))
> > @@ -4765,6 +4784,7 @@ static int mem_cgroup_move_charge_pte_ra
> > spinlock_t *ptl;
> >
> > retry:
> > + VM_BUG_ON(pmd_trans_huge(*pmd));
> > pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
> > for (; addr != end; addr += PAGE_SIZE) {
> > pte_t ptent = *(pte++);
> >
>

Thanks,
-Kame