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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 23544C19F32 for ; Wed, 5 Mar 2025 04:00:54 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5D1856B0082; Tue, 4 Mar 2025 23:00:53 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 582336B0083; Tue, 4 Mar 2025 23:00:53 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 449336B0085; Tue, 4 Mar 2025 23:00:53 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 2A15D6B0082 for ; Tue, 4 Mar 2025 23:00:53 -0500 (EST) Received: from smtpin17.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 88FF352CA8 for ; Wed, 5 Mar 2025 04:00:52 +0000 (UTC) X-FDA: 83186146344.17.A1D2B89 Received: from szxga04-in.huawei.com (szxga04-in.huawei.com [45.249.212.190]) by imf07.hostedemail.com (Postfix) with ESMTP id 8DD0440004 for ; Wed, 5 Mar 2025 04:00:49 +0000 (UTC) Authentication-Results: imf07.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf07.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.190 as permitted sender) smtp.mailfrom=liushixin2@huawei.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741147250; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding:in-reply-to: references; bh=2TkpkLJtqYC/VNTjXByWq/u3TdoHQv+9359p6z7k/rE=; b=7rFU7E8DkAlX85UpKE2sPMERPYPkfb2Qaeybbk9Ov12bkXYyZkMyunAPBn1B/UJFhEMStN CCzKlsZI9cHGfIR7735u/kW2cOypEedWcXT6Rg96wmBm87Drw8x+xY1XgiqFT1sWS820vW j4iLnlW4ZvCPxT1h9XTSFMQdyb4gf/k= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741147250; a=rsa-sha256; cv=none; b=ykpO76olOZwQdz7soL45ZljufyCCt9+qN9Rep3T5y1IggJlrJCMMYN7SJIuoMUMaEumoKT 2PVqz5nSfA7xwp4rreupn6AcYtGzYlYe1PqLtE7sF3On6SdQUv/rXt7DNAgMkiz0/seE8W SGu5fARnHOw2FN+QilXWtWkZlTY7CDU= ARC-Authentication-Results: i=1; imf07.hostedemail.com; dkim=none; dmarc=pass (policy=quarantine) header.from=huawei.com; spf=pass (imf07.hostedemail.com: domain of liushixin2@huawei.com designates 45.249.212.190 as permitted sender) smtp.mailfrom=liushixin2@huawei.com Received: from mail.maildlp.com (unknown [172.19.162.112]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4Z6zHz0jk5z2DjfM; Wed, 5 Mar 2025 11:56:31 +0800 (CST) Received: from kwepemg200013.china.huawei.com (unknown [7.202.181.64]) by mail.maildlp.com (Postfix) with ESMTPS id 6224A1400D3; Wed, 5 Mar 2025 12:00:43 +0800 (CST) Received: from huawei.com (10.175.113.32) by kwepemg200013.china.huawei.com (7.202.181.64) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Wed, 5 Mar 2025 12:00:42 +0800 From: Liu Shixin To: Muchun Song , Andrew Morton , David Hildenbrand , Oscar Salvador , Kefeng Wang , Peter Xu CC: , , Liu Shixin Subject: [PATCH v3] mm/hugetlb: update nr_huge_pages and surplus_huge_pages together Date: Wed, 5 Mar 2025 11:54:09 +0800 Message-ID: <20250305035409.2391344-1-liushixin2@huawei.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.175.113.32] X-ClientProxiedBy: dggems702-chm.china.huawei.com (10.3.19.179) To kwepemg200013.china.huawei.com (7.202.181.64) X-Rspam-User: X-Rspamd-Server: rspam12 X-Rspamd-Queue-Id: 8DD0440004 X-Stat-Signature: 67fy4z5ke6adq31nur5adsjheuztr534 X-HE-Tag: 1741147249-888027 X-HE-Meta: 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 PMqm1wWE byX+wShf4MB5cCuhZ3avXStWJFXCXyKyFvTutMPAae0aR4TTr2EdltJgwZrocNYEQf1nSBY5nh6HdIl4BsTzX3Zb/unqughIez2Yq4Gqu5N49KAQT6uLsur9LL64tQ3dm68/hP+cHVagG7R6dMtoWFKAP5kYi8JF5UeEIK///aonLEr2CzyMVQnaJcA7FlBv7RW1b9nRhUk/ske21DFsm5ENqhsZe7MBskfxt 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: List-Subscribe: List-Unsubscribe: In alloc_surplus_hugetlb_folio(), we increase nr_huge_pages and surplus_huge_pages separately. In the middle window, if we set nr_hugepages to smaller and satisfy count < persistent_huge_pages(h), the surplus_huge_pages will be increased by adjust_pool_surplus(). After adding delay in the middle window, we can reproduce the problem easily by following step: 1. echo 3 > /proc/sys/vm/nr_overcommit_hugepages 2. mmap two hugepages. When nr_huge_pages=2 and surplus_huge_pages=1, goto step 3. 3. echo 0 > /proc/sys/vm/nr_huge_pages Finally, nr_huge_pages is less than surplus_huge_pages. To fix the problem, call only_alloc_fresh_hugetlb_folio() instead and move down __prep_account_new_huge_page() into the hugetlb_lock. Fixes: 0c397daea1d4 ("mm, hugetlb: further simplify hugetlb allocation API") Signed-off-by: Liu Shixin --- v2->v3: Modify the comment suggested by Oscar. mm/hugetlb.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 9faa1034704ff..0e08d2fff2360 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -2253,11 +2253,20 @@ static struct folio *alloc_surplus_hugetlb_folio(struct hstate *h, goto out_unlock; spin_unlock_irq(&hugetlb_lock); - folio = alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask); + folio = only_alloc_fresh_hugetlb_folio(h, gfp_mask, nid, nmask, NULL); if (!folio) return NULL; + hugetlb_vmemmap_optimize_folio(h, folio); + spin_lock_irq(&hugetlb_lock); + /* + * nr_huge_pages needs to be adjusted within the same lock cycle + * as surplus_pages, otherwise it might confuse + * persistent_huge_pages() momentarily. + */ + __prep_account_new_huge_page(h, nid); + /* * We could have raced with the pool size change. * Double check that and simply deallocate the new page -- 2.34.1