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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 3CB95C2D0DB for ; Mon, 27 Jan 2020 17:38:39 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id EC20A214D8 for ; Mon, 27 Jan 2020 17:38:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=fb.com header.i=@fb.com header.b="ECcaESy+" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EC20A214D8 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=fb.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 9EBEC6B0006; Mon, 27 Jan 2020 12:38:38 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 99BCF6B0007; Mon, 27 Jan 2020 12:38:38 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 8B3406B026A; Mon, 27 Jan 2020 12:38:38 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0127.hostedemail.com [216.40.44.127]) by kanga.kvack.org (Postfix) with ESMTP id 753F66B0006 for ; Mon, 27 Jan 2020 12:38:38 -0500 (EST) Received: from smtpin12.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with SMTP id 3B4B01EF2 for ; Mon, 27 Jan 2020 17:38:38 +0000 (UTC) X-FDA: 76424123916.12.prose49_686c669b63357 X-HE-Tag: prose49_686c669b63357 X-Filterd-Recvd-Size: 7322 Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) by imf22.hostedemail.com (Postfix) with ESMTP for ; Mon, 27 Jan 2020 17:38:37 +0000 (UTC) Received: from pps.filterd (m0044012.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 00RHYOET026753 for ; Mon, 27 Jan 2020 09:38:36 -0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fb.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-type; s=facebook; bh=yMlJxXg/nvobeib23VDIeIVf1n+iIr1E4YDRwYeRhHc=; b=ECcaESy++70fV3jsOVt5ByNbSsgcnH589nMmeWs43Ok4GDWPfKv7S9WtzY1R7ZcLwnCA lwsmfeZtG4PGli4NfleAHimRYBzkJJneuslSwOQjjLVBNdZ8gohXCfRfGReYEk7O8Yz7 lrzDxszie5Aw+wfBrdDmvhlK2fxJcYiXLCU= Received: from mail.thefacebook.com ([163.114.132.120]) by mx0a-00082601.pphosted.com with ESMTP id 2xs6a2p72k-17 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT) for ; Mon, 27 Jan 2020 09:38:36 -0800 Received: from intmgw004.06.prn3.facebook.com (2620:10d:c085:108::4) by mail.thefacebook.com (2620:10d:c085:21d::7) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1779.2; Mon, 27 Jan 2020 09:38:13 -0800 Received: by devvm2643.prn2.facebook.com (Postfix, from userid 111017) id 9768B1DFEFC79; Mon, 27 Jan 2020 09:35:07 -0800 (PST) Smtp-Origin-Hostprefix: devvm From: Roman Gushchin Smtp-Origin-Hostname: devvm2643.prn2.facebook.com To: , Andrew Morton CC: Michal Hocko , Johannes Weiner , Shakeel Butt , Vladimir Davydov , , , Bharata B Rao , Yafang Shao , Roman Gushchin Smtp-Origin-Cluster: prn2c23 Subject: [PATCH v2 07/28] mm: memcg/slab: introduce mem_cgroup_from_obj() Date: Mon, 27 Jan 2020 09:34:32 -0800 Message-ID: <20200127173453.2089565-8-guro@fb.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200127173453.2089565-1-guro@fb.com> References: <20200127173453.2089565-1-guro@fb.com> X-FB-Internal: Safe MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.138,18.0.572 definitions=2020-01-27_06:2020-01-24,2020-01-27 signatures=0 X-Proofpoint-Spam-Details: rule=fb_default_notspam policy=fb_default score=0 phishscore=0 mlxlogscore=661 mlxscore=0 clxscore=1015 suspectscore=0 malwarescore=0 bulkscore=0 lowpriorityscore=0 impostorscore=0 adultscore=0 spamscore=0 priorityscore=1501 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-1911200001 definitions=main-2001270141 X-FB-Internal: deliver 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: Sometimes we need to get a memcg pointer from a charged kernel object. The right way to get it depends on whether it's a proper slab object or it's backed by raw pages (e.g. it's a vmalloc alloction). In the first case the kmem_cache->memcg_params.memcg indirection should be used; in other cases it's just page->mem_cgroup. To simplify this task and hide the implementation details let's introduce a mem_cgroup_from_obj() helper, which takes a pointer to any kernel object and returns a valid memcg pointer or NULL. Passing a kernel address rather than a pointer to a page will allow to use this helper for per-object (rather than per-page) tracked objects in the future. The caller is still responsible to ensure that the returned memcg isn't going away underneath: take the rcu read lock, cgroup mutex etc; depending on the context. mem_cgroup_from_kmem() defined in mm/list_lru.c is now obsolete and can be removed. Signed-off-by: Roman Gushchin --- include/linux/memcontrol.h | 7 +++++++ mm/list_lru.c | 12 +----------- mm/memcontrol.c | 32 +++++++++++++++++++++++++++++--- 3 files changed, 37 insertions(+), 14 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index c372bed6be80..24c50d004c46 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1427,6 +1427,8 @@ static inline int memcg_cache_id(struct mem_cgroup *memcg) return memcg ? memcg->kmemcg_id : -1; } +struct mem_cgroup *mem_cgroup_from_obj(void *p); + #else static inline int memcg_kmem_charge_page(struct page *page, gfp_t gfp, @@ -1470,6 +1472,11 @@ static inline void memcg_put_cache_ids(void) { } +static inline struct mem_cgroup *mem_cgroup_from_obj(void *p) +{ + return NULL; +} + #endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ diff --git a/mm/list_lru.c b/mm/list_lru.c index 0f1f6b06b7f3..8de5e3784ee4 100644 --- a/mm/list_lru.c +++ b/mm/list_lru.c @@ -57,16 +57,6 @@ list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx) return &nlru->lru; } -static __always_inline struct mem_cgroup *mem_cgroup_from_kmem(void *ptr) -{ - struct page *page; - - if (!memcg_kmem_enabled()) - return NULL; - page = virt_to_head_page(ptr); - return memcg_from_slab_page(page); -} - static inline struct list_lru_one * list_lru_from_kmem(struct list_lru_node *nlru, void *ptr, struct mem_cgroup **memcg_ptr) @@ -77,7 +67,7 @@ list_lru_from_kmem(struct list_lru_node *nlru, void *ptr, if (!nlru->memcg_lrus) goto out; - memcg = mem_cgroup_from_kmem(ptr); + memcg = mem_cgroup_from_obj(ptr); if (!memcg) goto out; diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8798702d165b..43010471621c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -757,13 +757,12 @@ void __mod_lruvec_state(struct lruvec *lruvec, enum node_stat_item idx, void __mod_lruvec_slab_state(void *p, enum node_stat_item idx, int val) { - struct page *page = virt_to_head_page(p); - pg_data_t *pgdat = page_pgdat(page); + pg_data_t *pgdat = page_pgdat(virt_to_page(p)); struct mem_cgroup *memcg; struct lruvec *lruvec; rcu_read_lock(); - memcg = memcg_from_slab_page(page); + memcg = mem_cgroup_from_obj(p); /* Untracked pages have no memcg, no lruvec. Update only the node */ if (!memcg || memcg == root_mem_cgroup) { @@ -2636,6 +2635,33 @@ static void commit_charge(struct page *page, struct mem_cgroup *memcg, } #ifdef CONFIG_MEMCG_KMEM +/* + * Returns a pointer to the memory cgroup to which the kernel object is charged. + * + * The caller must ensure the memcg lifetime, e.g. by taking rcu_read_lock(), + * cgroup_mutex, etc. + */ +struct mem_cgroup *mem_cgroup_from_obj(void *p) +{ + struct page *page; + + if (mem_cgroup_disabled()) + return NULL; + + page = virt_to_head_page(p); + + /* + * Slab pages don't have page->mem_cgroup set because corresponding + * kmem caches can be reparented during the lifetime. That's why + * memcg_from_slab_page() should be used instead. + */ + if (PageSlab(page)) + return memcg_from_slab_page(page); + + /* All other pages use page->mem_cgroup */ + return page->mem_cgroup; +} + static int memcg_alloc_cache_id(void) { int id, size; -- 2.24.1