From patchwork Thu Sep 9 01:10:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12482085 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C5165C4332F for ; Thu, 9 Sep 2021 01:10:08 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 606A76115B for ; Thu, 9 Sep 2021 01:10:08 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 606A76115B Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id DC6C56B0071; Wed, 8 Sep 2021 21:10:07 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D76D5940007; Wed, 8 Sep 2021 21:10:07 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id BF0CF6B0073; Wed, 8 Sep 2021 21:10:07 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0248.hostedemail.com [216.40.44.248]) by kanga.kvack.org (Postfix) with ESMTP id AD5086B0071 for ; Wed, 8 Sep 2021 21:10:07 -0400 (EDT) Received: from smtpin38.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id 3F7B918441403 for ; Thu, 9 Sep 2021 01:10:07 +0000 (UTC) X-FDA: 78566253654.38.8F37317 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf25.hostedemail.com (Postfix) with ESMTP id EA98AB000182 for ; Thu, 9 Sep 2021 01:10:06 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 00C9261158; Thu, 9 Sep 2021 01:10:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1631149806; bh=Qi5g0WJd95Lld7Mm36JDS4ey+bIpL2U8i+LE+7t0DLI=; h=Date:From:To:Subject:In-Reply-To:From; b=tjX2+W5MSJQBvZaQvgy8Uog1sLFUictDCV5dS3QSpYfquLIZL36s3y3i02xB/No63 yVlJms9wjDsYwnF2SQTHwpfwnt9HbBRrjjVyezXnZ5n9mzKoqmLRTSamTsx+ocesqM 719qPO22gqbK8XhJuq/EEQCISXpRAsdCNZdUEqyk= Date: Wed, 08 Sep 2021 18:10:05 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, liuzixian4@huawei.com, mike.kravetz@oracle.com, mm-commits@vger.kernel.org, naoya.horiguchi@nec.com, stable@vger.kernel.org, torvalds@linux-foundation.org Subject: [patch 2/8] mm/hugetlb: initialize hugetlb_usage in mm_init Message-ID: <20210909011005.6UTH8UzKk%akpm@linux-foundation.org> In-Reply-To: <20210908180859.d523d4bb4ad8eec11c61500d@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=tjX2+W5M; spf=pass (imf25.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Stat-Signature: gecaehda4widzu7pdb9iox1e8gjiusmu X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: EA98AB000182 X-HE-Tag: 1631149806-275471 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: Liu Zixian Subject: mm/hugetlb: initialize hugetlb_usage in mm_init After fork, the child process will get incorrect (2x) hugetlb_usage. If a process uses 5 2MB hugetlb pages in an anonymous mapping, HugetlbPages: 10240 kB and then forks, the child will show, HugetlbPages: 20480 kB The reason for double the amount is because hugetlb_usage will be copied from the parent and then increased when we copy page tables from parent to child. Child will have 2x actual usage. Fix this by adding hugetlb_count_init in mm_init. Link: https://lkml.kernel.org/r/20210826071742.877-1-liuzixian4@huawei.com Fixes: 5d317b2b6536 ("mm: hugetlb: proc: add HugetlbPages field to /proc/PID/status") Signed-off-by: Liu Zixian Reviewed-by: Naoya Horiguchi Reviewed-by: Mike Kravetz Cc: Signed-off-by: Andrew Morton --- include/linux/hugetlb.h | 9 +++++++++ kernel/fork.c | 1 + 2 files changed, 10 insertions(+) --- a/include/linux/hugetlb.h~mm-hugetlb-initialize-hugetlb_usage-in-mm_init +++ a/include/linux/hugetlb.h @@ -858,6 +858,11 @@ static inline spinlock_t *huge_pte_lockp void hugetlb_report_usage(struct seq_file *m, struct mm_struct *mm); +static inline void hugetlb_count_init(struct mm_struct *mm) +{ + atomic_long_set(&mm->hugetlb_usage, 0); +} + static inline void hugetlb_count_add(long l, struct mm_struct *mm) { atomic_long_add(l, &mm->hugetlb_usage); @@ -1042,6 +1047,10 @@ static inline spinlock_t *huge_pte_lockp return &mm->page_table_lock; } +static inline void hugetlb_count_init(struct mm_struct *mm) +{ +} + static inline void hugetlb_report_usage(struct seq_file *f, struct mm_struct *m) { } --- a/kernel/fork.c~mm-hugetlb-initialize-hugetlb_usage-in-mm_init +++ a/kernel/fork.c @@ -1063,6 +1063,7 @@ static struct mm_struct *mm_init(struct mm->pmd_huge_pte = NULL; #endif mm_init_uprobes_state(mm); + hugetlb_count_init(mm); if (current->mm) { mm->flags = current->mm->flags & MMF_INIT_MASK;