From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32756C3A589 for ; Tue, 20 Aug 2019 11:06:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D5FB920C01 for ; Tue, 20 Aug 2019 11:06:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D5FB920C01 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=virtuozzo.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 7AAF46B000C; Tue, 20 Aug 2019 07:06:45 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 7346C6B000D; Tue, 20 Aug 2019 07:06:45 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5FC8E6B000E; Tue, 20 Aug 2019 07:06:45 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0056.hostedemail.com [216.40.44.56]) by kanga.kvack.org (Postfix) with ESMTP id 405E46B000C for ; Tue, 20 Aug 2019 07:06:45 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id EBF75180AD808 for ; Tue, 20 Aug 2019 11:06:44 +0000 (UTC) X-FDA: 75842528328.19.year29_1dad04d5f1a60 X-HE-Tag: year29_1dad04d5f1a60 X-Filterd-Recvd-Size: 12534 Received: from relay.sw.ru (relay.sw.ru [185.231.240.75]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 20 Aug 2019 11:06:43 +0000 (UTC) Received: from [172.16.25.169] by relay.sw.ru with esmtp (Exim 4.92) (envelope-from ) id 1i01yK-0004pj-LF; Tue, 20 Aug 2019 14:06:40 +0300 Subject: Re: [v5 PATCH 4/4] mm: thp: make deferred split shrinker memcg aware To: Yang Shi , kirill.shutemov@linux.intel.com, hannes@cmpxchg.org, mhocko@suse.com, hughd@google.com, shakeelb@google.com, rientjes@google.com, cai@lca.pw, akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org References: <1565144277-36240-1-git-send-email-yang.shi@linux.alibaba.com> <1565144277-36240-5-git-send-email-yang.shi@linux.alibaba.com> From: Kirill Tkhai Message-ID: Date: Tue, 20 Aug 2019 14:06:39 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <1565144277-36240-5-git-send-email-yang.shi@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 07.08.2019 05:17, Yang Shi wrote: > Currently THP deferred split shrinker is not memcg aware, this may cause > premature OOM with some configuration. For example the below test would > run into premature OOM easily: > > $ cgcreate -g memory:thp > $ echo 4G > /sys/fs/cgroup/memory/thp/memory/limit_in_bytes > $ cgexec -g memory:thp transhuge-stress 4000 > > transhuge-stress comes from kernel selftest. > > It is easy to hit OOM, but there are still a lot THP on the deferred > split queue, memcg direct reclaim can't touch them since the deferred > split shrinker is not memcg aware. > > Convert deferred split shrinker memcg aware by introducing per memcg > deferred split queue. The THP should be on either per node or per memcg > deferred split queue if it belongs to a memcg. When the page is > immigrated to the other memcg, it will be immigrated to the target > memcg's deferred split queue too. > > Reuse the second tail page's deferred_list for per memcg list since the > same THP can't be on multiple deferred split queues. > > Cc: Kirill Tkhai > Cc: Johannes Weiner > Cc: Michal Hocko > Cc: "Kirill A . Shutemov" > Cc: Hugh Dickins > Cc: Shakeel Butt > Cc: David Rientjes > Cc: Qian Cai > Acked-by: Kirill A. Shutemov > Signed-off-by: Yang Shi Reviewed-by: Kirill Tkhai But, please, see below one small suggestion. > --- > include/linux/huge_mm.h | 9 ++++++ > include/linux/memcontrol.h | 4 +++ > include/linux/mm_types.h | 1 + > mm/huge_memory.c | 76 +++++++++++++++++++++++++++++++++++++++------- > mm/memcontrol.c | 24 +++++++++++++++ > 5 files changed, 103 insertions(+), 11 deletions(-) > > diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h > index 45ede62..61c9ffd 100644 > --- a/include/linux/huge_mm.h > +++ b/include/linux/huge_mm.h > @@ -267,6 +267,15 @@ static inline bool thp_migration_supported(void) > return IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION); > } > > +static inline struct list_head *page_deferred_list(struct page *page) > +{ > + /* > + * Global or memcg deferred list in the second tail pages is > + * occupied by compound_head. > + */ > + return &page[2].deferred_list; > +} > + > #else /* CONFIG_TRANSPARENT_HUGEPAGE */ > #define HPAGE_PMD_SHIFT ({ BUILD_BUG(); 0; }) > #define HPAGE_PMD_MASK ({ BUILD_BUG(); 0; }) > diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h > index 5771816..cace365 100644 > --- a/include/linux/memcontrol.h > +++ b/include/linux/memcontrol.h > @@ -312,6 +312,10 @@ struct mem_cgroup { > struct list_head event_list; > spinlock_t event_list_lock; > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + struct deferred_split deferred_split_queue; > +#endif > + > struct mem_cgroup_per_node *nodeinfo[0]; > /* WARNING: nodeinfo must be the last member here */ > }; > diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h > index 3a37a89..156640c 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -139,6 +139,7 @@ struct page { > struct { /* Second tail page of compound page */ > unsigned long _compound_pad_1; /* compound_head */ > unsigned long _compound_pad_2; > + /* For both global and memcg */ > struct list_head deferred_list; > }; > struct { /* Page table pages */ > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index e0d8e08..c9a596e 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -495,11 +495,25 @@ pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma) > return pmd; > } > > -static inline struct list_head *page_deferred_list(struct page *page) > +#ifdef CONFIG_MEMCG > +static inline struct deferred_split *get_deferred_split_queue(struct page *page) > { > - /* ->lru in the tail pages is occupied by compound_head. */ > - return &page[2].deferred_list; > + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; > + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); > + > + if (memcg) > + return &memcg->deferred_split_queue; > + else > + return &pgdat->deferred_split_queue; > +} > +#else > +static inline struct deferred_split *get_deferred_split_queue(struct page *page) > +{ > + struct pglist_data *pgdat = NODE_DATA(page_to_nid(page)); > + > + return &pgdat->deferred_split_queue; > } > +#endif > > void prep_transhuge_page(struct page *page) > { > @@ -2658,7 +2672,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > { > struct page *head = compound_head(page); > struct pglist_data *pgdata = NODE_DATA(page_to_nid(head)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > struct anon_vma *anon_vma = NULL; > struct address_space *mapping = NULL; > int count, mapcount, extra_pins, ret; > @@ -2794,8 +2808,7 @@ int split_huge_page_to_list(struct page *page, struct list_head *list) > > void free_transhuge_page(struct page *page) > { > - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > unsigned long flags; > > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > @@ -2809,17 +2822,37 @@ void free_transhuge_page(struct page *page) > > void deferred_split_huge_page(struct page *page) > { > - struct pglist_data *pgdata = NODE_DATA(page_to_nid(page)); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue = get_deferred_split_queue(page); > +#ifdef CONFIG_MEMCG > + struct mem_cgroup *memcg = compound_head(page)->mem_cgroup; > +#endif > unsigned long flags; > > VM_BUG_ON_PAGE(!PageTransHuge(page), page); > > + /* > + * The try_to_unmap() in page reclaim path might reach here too, > + * this may cause a race condition to corrupt deferred split queue. > + * And, if page reclaim is already handling the same page, it is > + * unnecessary to handle it again in shrinker. > + * > + * Check PageSwapCache to determine if the page is being > + * handled by page reclaim since THP swap would add the page into > + * swap cache before calling try_to_unmap(). > + */ > + if (PageSwapCache(page)) > + return; > + > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > if (list_empty(page_deferred_list(page))) { > count_vm_event(THP_DEFERRED_SPLIT_PAGE); > list_add_tail(page_deferred_list(page), &ds_queue->split_queue); > ds_queue->split_queue_len++; > +#ifdef CONFIG_MEMCG > + if (memcg) > + memcg_set_shrinker_bit(memcg, page_to_nid(page), > + deferred_split_shrinker.id); > +#endif > } > spin_unlock_irqrestore(&ds_queue->split_queue_lock, flags); > } > @@ -2827,8 +2860,19 @@ void deferred_split_huge_page(struct page *page) > static unsigned long deferred_split_count(struct shrinker *shrink, > struct shrink_control *sc) > { > + struct deferred_split *ds_queue; > struct pglist_data *pgdata = NODE_DATA(sc->nid); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + > +#ifdef CONFIG_MEMCG > + if (!sc->memcg) { > + ds_queue = &pgdata->deferred_split_queue; > + return READ_ONCE(ds_queue->split_queue_len); > + } > + > + ds_queue = &sc->memcg->deferred_split_queue; > +#else > + ds_queue = &pgdata->deferred_split_queue; > +#endif > return READ_ONCE(ds_queue->split_queue_len); > } Can we write this a little more compact? struct deferred_split *ds_queue = &pgdata->deferred_split_queue; #ifdef CONFIG_MEMCG if (sc->memcg) ds_queue = &sc->memcg->deferred_split_queue; #endif Or just introduce a helper (something like get_sc_deferred_split_queue). The same is in .scan method. > > @@ -2836,12 +2880,21 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, > struct shrink_control *sc) > { > struct pglist_data *pgdata = NODE_DATA(sc->nid); > - struct deferred_split *ds_queue = &pgdata->deferred_split_queue; > + struct deferred_split *ds_queue; > unsigned long flags; > LIST_HEAD(list), *pos, *next; > struct page *page; > int split = 0; > > +#ifdef CONFIG_MEMCG > + if (sc->memcg) > + ds_queue = &sc->memcg->deferred_split_queue; > + else > + ds_queue = &pgdata->deferred_split_queue; > +#else > + ds_queue = &pgdata->deferred_split_queue; > +#endif > + > spin_lock_irqsave(&ds_queue->split_queue_lock, flags); > /* Take pin on all head pages to avoid freeing them under us */ > list_for_each_safe(pos, next, &ds_queue->split_queue) { > @@ -2888,7 +2941,8 @@ static unsigned long deferred_split_scan(struct shrinker *shrink, > .count_objects = deferred_split_count, > .scan_objects = deferred_split_scan, > .seeks = DEFAULT_SEEKS, > - .flags = SHRINKER_NUMA_AWARE, > + .flags = SHRINKER_NUMA_AWARE | SHRINKER_MEMCG_AWARE | > + SHRINKER_NONSLAB, > }; > > #ifdef CONFIG_DEBUG_FS > diff --git a/mm/memcontrol.c b/mm/memcontrol.c > index d90ded1..da4a411 100644 > --- a/mm/memcontrol.c > +++ b/mm/memcontrol.c > @@ -4698,6 +4698,11 @@ static struct mem_cgroup *mem_cgroup_alloc(void) > #ifdef CONFIG_CGROUP_WRITEBACK > INIT_LIST_HEAD(&memcg->cgwb_list); > #endif > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + spin_lock_init(&memcg->deferred_split_queue.split_queue_lock); > + INIT_LIST_HEAD(&memcg->deferred_split_queue.split_queue); > + memcg->deferred_split_queue.split_queue_len = 0; > +#endif > idr_replace(&mem_cgroup_idr, memcg, memcg->id.id); > return memcg; > fail: > @@ -5071,6 +5076,14 @@ static int mem_cgroup_move_account(struct page *page, > __mod_memcg_state(to, NR_WRITEBACK, nr_pages); > } > > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + if (compound && !list_empty(page_deferred_list(page))) { > + spin_lock(&from->deferred_split_queue.split_queue_lock); > + list_del_init(page_deferred_list(page)); > + from->deferred_split_queue.split_queue_len--; > + spin_unlock(&from->deferred_split_queue.split_queue_lock); > + } > +#endif > /* > * It is safe to change page->mem_cgroup here because the page > * is referenced, charged, and isolated - we can't race with > @@ -5079,6 +5092,17 @@ static int mem_cgroup_move_account(struct page *page, > > /* caller should have done css_get */ > page->mem_cgroup = to; > + > +#ifdef CONFIG_TRANSPARENT_HUGEPAGE > + if (compound && list_empty(page_deferred_list(page))) { > + spin_lock(&to->deferred_split_queue.split_queue_lock); > + list_add_tail(page_deferred_list(page), > + &to->deferred_split_queue.split_queue); > + to->deferred_split_queue.split_queue_len++; > + spin_unlock(&to->deferred_split_queue.split_queue_lock); > + } > +#endif > + > spin_unlock_irqrestore(&from->move_lock, flags); > > ret = 0; >