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 9A2EAC282DE for ; Thu, 6 Mar 2025 09:15:41 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 3585B280003; Thu, 6 Mar 2025 04:15:39 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3088C280001; Thu, 6 Mar 2025 04:15:39 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1D011280003; Thu, 6 Mar 2025 04:15:39 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id F032A280001 for ; Thu, 6 Mar 2025 04:15:38 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 6CF2E161337 for ; Thu, 6 Mar 2025 09:15:40 +0000 (UTC) X-FDA: 83190568440.08.A366C39 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by imf11.hostedemail.com (Postfix) with ESMTP id 3EFBB40003 for ; Thu, 6 Mar 2025 09:15:38 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=utGPIsfH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=bSiUM66c; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=utGPIsfH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=bSiUM66c; spf=pass (imf11.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1741252538; 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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=BArABqxQWjf53Ufa+sY0G4LVWnCgkOwNaWpIsfl+qiU=; b=WlLwrNt+81ECIJ5+EXYdH3Rnom4EjCUS/wzJkGz4z/IzXkpMZukcSY0CbM7/lXbBviAZKR IVGhxwdywUnJTY3fcTlPmrzF12qOBO0ezThA58qMcowlO25GspMN0rB9vd1v86Gyy0H6X1 /oM/d5OvI2FkEKUAptrYLRDpMckJ/UI= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=utGPIsfH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=bSiUM66c; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=utGPIsfH; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=bSiUM66c; spf=pass (imf11.hostedemail.com: domain of osalvador@suse.de designates 195.135.223.130 as permitted sender) smtp.mailfrom=osalvador@suse.de; dmarc=pass (policy=none) header.from=suse.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1741252538; a=rsa-sha256; cv=none; b=tB7UrW6p51Mvl5/q4HTTcVwy8y3z+CPXCIIXy42eXW0F/bBFc8PnvwvtWtz4KQjYRG2cFx XwkMwvRv1VdygIKLgu54gfZyoRcINXRZhwqKhoFFV6MrCr4JM72dAQdZAO3NPbNBx5sPTK Q5+dNm6bx2vYzx/5BckhejIHX00yf0E= Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id BB28B211BA; Thu, 6 Mar 2025 09:15:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1741252536; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BArABqxQWjf53Ufa+sY0G4LVWnCgkOwNaWpIsfl+qiU=; b=utGPIsfH8r+y/3qe/JjVe4c2zPQoEQ0mg69wcA6yWmaAhZ6AVdJ/t/DlRq2j+sbqLGIygU LSdjAeQzqID1E9HMvjWsEHUjHp6mg4n0UWlIU6V/I+TVcqMVqI67UjE6nGakXkNQNINZsI CFWjTfLhL0Klyf6vhrwq0WzuV9ttizw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1741252536; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BArABqxQWjf53Ufa+sY0G4LVWnCgkOwNaWpIsfl+qiU=; b=bSiUM66chjQG/c55yjwRC4UQJyHu7bqTfnCORRyF1oUOuM74I2pSTOOvFDVBsULZ60hkJt OJX+QM8LZp/LvXDQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1741252536; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BArABqxQWjf53Ufa+sY0G4LVWnCgkOwNaWpIsfl+qiU=; b=utGPIsfH8r+y/3qe/JjVe4c2zPQoEQ0mg69wcA6yWmaAhZ6AVdJ/t/DlRq2j+sbqLGIygU LSdjAeQzqID1E9HMvjWsEHUjHp6mg4n0UWlIU6V/I+TVcqMVqI67UjE6nGakXkNQNINZsI CFWjTfLhL0Klyf6vhrwq0WzuV9ttizw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1741252536; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=BArABqxQWjf53Ufa+sY0G4LVWnCgkOwNaWpIsfl+qiU=; b=bSiUM66chjQG/c55yjwRC4UQJyHu7bqTfnCORRyF1oUOuM74I2pSTOOvFDVBsULZ60hkJt OJX+QM8LZp/LvXDQ== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 48C4E13A61; Thu, 6 Mar 2025 09:15:36 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Na0ID7hnyWcmEwAAD6G6ig (envelope-from ); Thu, 06 Mar 2025 09:15:36 +0000 Date: Thu, 6 Mar 2025 10:15:34 +0100 From: Oscar Salvador To: Liu Shixin Cc: Muchun Song , Andrew Morton , David Hildenbrand , Kefeng Wang , Peter Xu , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] mm/hugetlb: update nr_huge_pages and surplus_huge_pages together Message-ID: References: <20250305035409.2391344-1-liushixin2@huawei.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250305035409.2391344-1-liushixin2@huawei.com> X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 3EFBB40003 X-Stat-Signature: jhtft4ffp7id8uucc7jzaw4u3d8bqzw7 X-HE-Tag: 1741252538-193540 X-HE-Meta: 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 i0B9O9SB HVGnvZ58DhBM/Qxgxw5c2Inuteqpj+wSMTa8zEa8n0qQhpQqjgtlqMZhUbxFifXhbtHo3+N8xEYFchjo8HvBFHmWEScPlXMn5WrWyuPbfEDUpfefRkeI6D5SOGznc8D8m7tR79OtOV5ffSrsHNjsEorFscS7xdv0hRcNoOuJJFQ2p0PlmNxEv0dOS2CSBhr6+E+aFUnKLDN/1XJJoW+ai/Cat6jdtMykrVmHuicNUrHfILEQNHudFQR/yQeXusWvfPv0R3jLmBwCXGB2vGtwoGZ/u/UgQLh9LoiADGiqn5djZfobNE9LU3OnPBAHtts2Z467ZqsZM6nRmppE= 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: On Wed, Mar 05, 2025 at 11:54:09AM +0800, Liu Shixin wrote: > 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 Acked-by: Oscar Salvador -- Oscar Salvador SUSE Labs