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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 36ECBC19F35 for ; Mon, 16 Aug 2021 07:12:53 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id D8ECC6023E for ; Mon, 16 Aug 2021 07:12:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org D8ECC6023E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 4E6786B0071; Mon, 16 Aug 2021 03:12:51 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 494E48D0002; Mon, 16 Aug 2021 03:12:51 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35D7D6B0072; Mon, 16 Aug 2021 03:12:51 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0007.hostedemail.com [216.40.44.7]) by kanga.kvack.org (Postfix) with ESMTP id 1351E8D0002 for ; Mon, 16 Aug 2021 03:12:51 -0400 (EDT) Received: from smtpin37.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id AAD1E181AEF3C for ; Mon, 16 Aug 2021 07:12:50 +0000 (UTC) X-FDA: 78480076500.37.7A518E7 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by imf13.hostedemail.com (Postfix) with ESMTP id EBAC5101E5C4 for ; Mon, 16 Aug 2021 07:12:49 +0000 (UTC) Received: from dggemv704-chm.china.huawei.com (unknown [172.30.72.57]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Gp4yQ1MGwz880v; Mon, 16 Aug 2021 15:08:46 +0800 (CST) Received: from dggema756-chm.china.huawei.com (10.1.198.198) by dggemv704-chm.china.huawei.com (10.3.19.47) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2176.2; Mon, 16 Aug 2021 15:12:47 +0800 Received: from localhost.localdomain (10.175.112.125) by dggema756-chm.china.huawei.com (10.1.198.198) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2176.2; Mon, 16 Aug 2021 15:12:46 +0800 From: Chen Huang To: Roman Gushchin , Muchun Song , "Wang Hai" , Greg Kroah-Hartman CC: , , , Chen Huang , Andrew Morton , Alexei Starovoitov Subject: [PATCH 5.10.y 04/11] mm: Convert page kmemcg type to a page memcg flag Date: Mon, 16 Aug 2021 07:21:40 +0000 Message-ID: <20210816072147.3481782-5-chenhuang5@huawei.com> X-Mailer: git-send-email 2.18.0.huawei.25 In-Reply-To: <20210816072147.3481782-1-chenhuang5@huawei.com> References: <20210816072147.3481782-1-chenhuang5@huawei.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.112.125] X-ClientProxiedBy: dggems705-chm.china.huawei.com (10.3.19.182) To dggema756-chm.china.huawei.com (10.1.198.198) X-CFilter-Loop: Reflected X-Rspamd-Queue-Id: EBAC5101E5C4 Authentication-Results: imf13.hostedemail.com; dkim=none; spf=pass (imf13.hostedemail.com: domain of chenhuang5@huawei.com designates 45.249.212.188 as permitted sender) smtp.mailfrom=chenhuang5@huawei.com; dmarc=pass (policy=none) header.from=huawei.com X-Rspamd-Server: rspam01 X-Stat-Signature: sankm6x6w95o1dobgwsxhnp6qhyxbj73 X-HE-Tag: 1629097969-809575 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: From: Roman Gushchin PageKmemcg flag is currently defined as a page type (like buddy, offline, table and guard). Semantically it means that the page was accounted as a kernel memory by the page allocator and has to be uncharged on the release. As a side effect of defining the flag as a page type, the accounted page can't be mapped to userspace (look at page_has_type() and comments above). In particular, this blocks the accounting of vmalloc-backed memory used by some bpf maps, because these maps do map the memory to userspace. One option is to fix it by complicating the access to page->mapcount, which provides some free bits for page->page_type. But it's way better to move this flag into page->memcg_data flags. Indeed, the flag makes no sense without enabled memory cgroups and memory cgroup pointer set in particular. This commit replaces PageKmemcg() and __SetPageKmemcg() with PageMemcgKmem() and an open-coded OR operation setting the memcg pointer with the MEMCG_DATA_KMEM bit. __ClearPageKmemcg() can be simple deleted, as the whole memcg_data is zeroed at once. As a bonus, on !CONFIG_MEMCG build the PageMemcgKmem() check will be compiled out. Signed-off-by: Roman Gushchin Signed-off-by: Andrew Morton Signed-off-by: Alexei Starovoitov Reviewed-by: Shakeel Butt Acked-by: Johannes Weiner Acked-by: Michal Hocko Link: https://lkml.kernel.org/r/20201027001657.3398190-5-guro@fb.com Link: https://lore.kernel.org/bpf/20201201215900.3569844-5-guro@fb.com Signed-off-by: Chen Huang --- include/linux/memcontrol.h | 37 +++++++++++++++++++++++++++++++++---- include/linux/page-flags.h | 11 ++--------- mm/memcontrol.c | 16 +++++----------- mm/page_alloc.c | 4 ++-- 4 files changed, 42 insertions(+), 26 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 4a0feb9d4b82..1a357edd2a1e 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -346,8 +346,10 @@ extern struct mem_cgroup *root_mem_cgroup; enum page_memcg_data_flags { /* page->memcg_data is a pointer to an objcgs vector */ MEMCG_DATA_OBJCGS = (1UL << 0), + /* page has been accounted as a non-slab kernel page */ + MEMCG_DATA_KMEM = (1UL << 1), /* the next bit after the last actual flag */ - __NR_MEMCG_DATA_FLAGS = (1UL << 1), + __NR_MEMCG_DATA_FLAGS = (1UL << 2), }; #define MEMCG_DATA_FLAGS_MASK (__NR_MEMCG_DATA_FLAGS - 1) @@ -369,8 +371,12 @@ enum page_memcg_data_flags { */ static inline struct mem_cgroup *page_memcg(struct page *page) { + unsigned long memcg_data = page->memcg_data; + VM_BUG_ON_PAGE(PageSlab(page), page); - return (struct mem_cgroup *)page->memcg_data; + VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_OBJCGS, page); + + return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); } /* @@ -387,7 +393,8 @@ static inline struct mem_cgroup *page_memcg_rcu(struct page *page) VM_BUG_ON_PAGE(PageSlab(page), page); WARN_ON_ONCE(!rcu_read_lock_held()); - return (struct mem_cgroup *)READ_ONCE(page->memcg_data); + return (struct mem_cgroup *)(READ_ONCE(page->memcg_data) & + ~MEMCG_DATA_FLAGS_MASK); } /* @@ -416,7 +423,21 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) if (memcg_data & MEMCG_DATA_OBJCGS) return NULL; - return (struct mem_cgroup *)memcg_data; + return (struct mem_cgroup *)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); +} + +/* + * PageMemcgKmem - check if the page has MemcgKmem flag set + * @page: a pointer to the page struct + * + * Checks if the page has MemcgKmem flag set. The caller must ensure that + * the page has an associated memory cgroup. It's not safe to call this function + * against some types of pages, e.g. slab pages. + */ +static inline bool PageMemcgKmem(struct page *page) +{ + VM_BUG_ON_PAGE(page->memcg_data & MEMCG_DATA_OBJCGS, page); + return page->memcg_data & MEMCG_DATA_KMEM; } #ifdef CONFIG_MEMCG_KMEM @@ -435,6 +456,7 @@ static inline struct obj_cgroup **page_objcgs(struct page *page) unsigned long memcg_data = READ_ONCE(page->memcg_data); VM_BUG_ON_PAGE(memcg_data && !(memcg_data & MEMCG_DATA_OBJCGS), page); + VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, page); return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); } @@ -454,6 +476,8 @@ static inline struct obj_cgroup **page_objcgs_check(struct page *page) if (!memcg_data || !(memcg_data & MEMCG_DATA_OBJCGS)) return NULL; + VM_BUG_ON_PAGE(memcg_data & MEMCG_DATA_KMEM, page); + return (struct obj_cgroup **)(memcg_data & ~MEMCG_DATA_FLAGS_MASK); } @@ -1114,6 +1138,11 @@ static inline struct mem_cgroup *page_memcg_check(struct page *page) return NULL; } +static inline bool PageMemcgKmem(struct page *page) +{ + return false; +} + static inline bool mem_cgroup_is_root(struct mem_cgroup *memcg) { return true; diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 4f6ba9379112..fc0e1bd48e73 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -715,9 +715,8 @@ PAGEFLAG_FALSE(DoubleMap) #define PAGE_MAPCOUNT_RESERVE -128 #define PG_buddy 0x00000080 #define PG_offline 0x00000100 -#define PG_kmemcg 0x00000200 -#define PG_table 0x00000400 -#define PG_guard 0x00000800 +#define PG_table 0x00000200 +#define PG_guard 0x00000400 #define PageType(page, flag) \ ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) @@ -768,12 +767,6 @@ PAGE_TYPE_OPS(Buddy, buddy) */ PAGE_TYPE_OPS(Offline, offline) -/* - * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on - * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. - */ -PAGE_TYPE_OPS(Kmemcg, kmemcg) - /* * Marks pages in use as page tables. */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index b9f49ddc5ced..abeaf5cede74 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3098,8 +3098,8 @@ int __memcg_kmem_charge_page(struct page *page, gfp_t gfp, int order) if (memcg && !mem_cgroup_is_root(memcg)) { ret = __memcg_kmem_charge(memcg, gfp, 1 << order); if (!ret) { - page->memcg_data = (unsigned long)memcg; - __SetPageKmemcg(page); + page->memcg_data = (unsigned long)memcg | + MEMCG_DATA_KMEM; return 0; } css_put(&memcg->css); @@ -3124,10 +3124,6 @@ void __memcg_kmem_uncharge_page(struct page *page, int order) __memcg_kmem_uncharge(memcg, nr_pages); page->memcg_data = 0; css_put(&memcg->css); - - /* slab pages do not have PageKmemcg flag set */ - if (PageKmemcg(page)) - __ClearPageKmemcg(page); } static bool consume_obj_stock(struct obj_cgroup *objcg, unsigned int nr_bytes) @@ -6902,12 +6898,10 @@ static void uncharge_page(struct page *page, struct uncharge_gather *ug) nr_pages = compound_nr(page); ug->nr_pages += nr_pages; - if (!PageKmemcg(page)) { - ug->pgpgout++; - } else { + if (PageMemcgKmem(page)) ug->nr_kmem += nr_pages; - __ClearPageKmemcg(page); - } + else + ug->pgpgout++; ug->dummy_page = page; page->memcg_data = 0; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ef19a693721f..8ec194271b91 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1216,7 +1216,7 @@ static __always_inline bool free_pages_prepare(struct page *page, * Do not let hwpoison pages hit pcplists/buddy * Untie memcg state and reset page's owner */ - if (memcg_kmem_enabled() && PageKmemcg(page)) + if (memcg_kmem_enabled() && PageMemcgKmem(page)) __memcg_kmem_uncharge_page(page, order); reset_page_owner(page, order); return false; @@ -1246,7 +1246,7 @@ static __always_inline bool free_pages_prepare(struct page *page, } if (PageMappingFlags(page)) page->mapping = NULL; - if (memcg_kmem_enabled() && PageKmemcg(page)) + if (memcg_kmem_enabled() && PageMemcgKmem(page)) __memcg_kmem_uncharge_page(page, order); if (check_free) bad += check_free_page(page); -- 2.18.0.huawei.25