Re: [PATCH 36 of 66] memcg compound

From: Mel Gorman
Date: Thu Nov 18 2010 - 10:26:48 EST

On Wed, Nov 03, 2010 at 04:28:11PM +0100, Andrea Arcangeli wrote:
> From: Andrea Arcangeli <aarcange@xxxxxxxxxx>
>
> Teach memcg to charge/uncharge compound pages.
>
> Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
> Acked-by: Rik van Riel <riel@xxxxxxxxxx>
> ---
>
> 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()


> {
> 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);
>
> /*
> * 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;
> 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++);
>

--
Mel Gorman
Part-time Phd Student Linux Technology Center
University of Limerick IBM Dublin Software Lab
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