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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 319A2F36C2A for ; Mon, 20 Apr 2026 06:55:12 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 72A7E6B00F9; Mon, 20 Apr 2026 02:55:11 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 702056B00FA; Mon, 20 Apr 2026 02:55:11 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 6402D6B00FE; Mon, 20 Apr 2026 02:55:11 -0400 (EDT) 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 533546B00F9 for ; Mon, 20 Apr 2026 02:55:11 -0400 (EDT) Received: from smtpin16.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 0409E160909 for ; Mon, 20 Apr 2026 06:55:10 +0000 (UTC) X-FDA: 84678022422.16.ACCC184 Received: from out30-119.freemail.mail.aliyun.com (out30-119.freemail.mail.aliyun.com [115.124.30.119]) by imf30.hostedemail.com (Postfix) with ESMTP id 2E00A80004 for ; Mon, 20 Apr 2026 06:55:06 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=tn5ztGqB; spf=pass (imf30.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.119 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1776668109; 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:in-reply-to:references:references:dkim-signature; bh=4wwaB5GIadZhT3WNLdwXoaV7zc2xYRrQwirl3loMrXg=; b=0kSGrXp/lBwHcS2VmyMu/R9ibEk33JEJYsOi/hYQ9Bsv64y0mVHe8o6a1rmLYYgTJ6ns6P Ine7lvYVKQgbf/3YKDqbkA8BxG05+LgxfyKGvUm1D1Ur1GBGVp3IGSRwSkRbXmziG0qAwO R5OyypmT9wM57vZO+e6s+7YWWa2YwFs= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=linux.alibaba.com header.s=default header.b=tn5ztGqB; spf=pass (imf30.hostedemail.com: domain of baolin.wang@linux.alibaba.com designates 115.124.30.119 as permitted sender) smtp.mailfrom=baolin.wang@linux.alibaba.com; dmarc=pass (policy=none) header.from=linux.alibaba.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1776668109; a=rsa-sha256; cv=none; b=Kqdj+aco8eLU8icBxjQnUIt/Y2JukMaKujGQMoTLlj48u7yetx5zBEmo8ixpH8KaMl+ItT 2/0YTc27oDmtkGhXB67vPdMfmoYzr6h98zADdockETTJuFVD+1Lt6OQ9rjzdrZi/cAfj8b lA2zCrse1L4ohgXuBAkGXa968u7hB9g= DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1776668103; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=4wwaB5GIadZhT3WNLdwXoaV7zc2xYRrQwirl3loMrXg=; b=tn5ztGqBDQEQ5IfiUVEK2xVgZ/YCJHkN0qgkD+aM9kOI8AAXgXFNe0UQuTsR6cddpknrhwnxkGHeIkJHtuzdqOTzyhPcFTnGMmAdo9KM1uXCOVSZcmz6lSJQMld2IE4xZG7g0wkmMgsw5puxmQheM36PeOLpOQLTmIa8fUcE9zA= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R651e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037009110;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=27;SR=0;TI=SMTPD_---0X1IKCmb_1776668101; Received: from 30.74.144.127(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0X1IKCmb_1776668101 cluster:ay36) by smtp.aliyun-inc.com; Mon, 20 Apr 2026 14:55:02 +0800 Message-ID: Date: Mon, 20 Apr 2026 14:55:00 +0800 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 7.2 v3 04/12] mm/khugepaged: remove READ_ONLY_THP_FOR_FS check in hugepage_pmd_enabled() To: Zi Yan , "Matthew Wilcox (Oracle)" , Song Liu Cc: Chris Mason , David Sterba , Alexander Viro , Christian Brauner , Jan Kara , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Shuah Khan , linux-btrfs@vger.kernel.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org References: <20260418024429.4055056-1-ziy@nvidia.com> <20260418024429.4055056-5-ziy@nvidia.com> From: Baolin Wang In-Reply-To: <20260418024429.4055056-5-ziy@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: hhwghd5y1aikk8mfrewosncspfe5wpes X-Rspam-User: X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 2E00A80004 X-HE-Tag: 1776668106-506319 X-HE-Meta: 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 47sdyaqX nodlyp/mXrGXeF/unHLZ8NHtWA/qhRjIf+JbgZ6zWdEIi62zNZhG7TKY+PZlyqK6szVFzO4boM33YdsYBYDO531rPPbHmpJiJebzFFW6nG4Ye9QLVtC1GRCdUTRExwIIQQaZTFv7b9GgudXRxerUm7FFxP9IXPsjbv+5fbaVnLPBLnCcyfLDScqPgrtvlxgpBnsiT7eZxqBhYL2rwU++HUfl63I3bjq5X5AOqTtooIfE+Wgi9svhd2A4LH6UlW5aLAyELKWy/4Tm5xwD/8k1WNcZnlq7fBT5O1nAw9isI4Bs1tOIOoeuLgJVNNbagaU3wJ3AhpVOb1N5jgGP24Uay1eS123VVP5gyYxNO Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 4/18/26 10:44 AM, Zi Yan wrote: > Remove READ_ONLY_THP_FOR_FS and khugepaged for file-backed pmd-sized > hugepages are enabled by the global transparent hugepage control. > khugepaged can still be enabled by per-size control for anon and shmem when > the global control is off. > > Add shmem_hpage_pmd_enabled() stub for !CONFIG_SHMEM to remove > IS_ENABLED(SHMEM) in hugepage_pmd_enabled(). > > Signed-off-by: Zi Yan > --- > include/linux/shmem_fs.h | 2 +- > mm/khugepaged.c | 28 ++++++++++++++++------------ > 2 files changed, 17 insertions(+), 13 deletions(-) > > diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h > index 1a345142af7d..dff8fb6ddac0 100644 > --- a/include/linux/shmem_fs.h > +++ b/include/linux/shmem_fs.h > @@ -127,7 +127,7 @@ int shmem_writeout(struct folio *folio, struct swap_iocb **plug, > void shmem_truncate_range(struct inode *inode, loff_t start, uoff_t end); > int shmem_unuse(unsigned int type); > > -#ifdef CONFIG_TRANSPARENT_HUGEPAGE > +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && defined(CONFIG_SHMEM) > unsigned long shmem_allowable_huge_orders(struct inode *inode, > struct vm_area_struct *vma, pgoff_t index, > loff_t write_end, bool shmem_huge_force); > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 1c0fdc81d276..718a2d06d1e6 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -406,18 +406,8 @@ static inline int collapse_test_exit_or_disable(struct mm_struct *mm) > mm_flags_test(MMF_DISABLE_THP_COMPLETELY, mm); > } > > -static bool hugepage_pmd_enabled(void) > +static inline bool anon_hpage_pmd_enabled(void) > { > - /* > - * We cover the anon, shmem and the file-backed case here; file-backed > - * hugepages, when configured in, are determined by the global control. > - * Anon pmd-sized hugepages are determined by the pmd-size control. > - * Shmem pmd-sized hugepages are also determined by its pmd-size control, > - * except when the global shmem_huge is set to SHMEM_HUGE_DENY. > - */ > - if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && > - hugepage_global_enabled()) > - return true; > if (test_bit(PMD_ORDER, &huge_anon_orders_always)) > return true; > if (test_bit(PMD_ORDER, &huge_anon_orders_madvise)) > @@ -425,7 +415,21 @@ static bool hugepage_pmd_enabled(void) > if (test_bit(PMD_ORDER, &huge_anon_orders_inherit) && > hugepage_global_enabled()) > return true; > - if (IS_ENABLED(CONFIG_SHMEM) && shmem_hpage_pmd_enabled()) > + return false; > +} > + > +static bool hugepage_pmd_enabled(void) > +{ > + /* > + * Anon, shmem and file-backed pmd-size hugepages are all determined by > + * the global control. If the global control is off, anon and shmem > + * pmd-sized hugepages are also determined by its per-size control. > + */ Personally, I found the previous comments clearer to me. The statement "Anon, shmem pmd-size hugepages are all determined by the global control" seems somewhat confusing. For example, if hugepage_global_enabled() returns true but the pmd-sized sub-control is set to 'never', that means anon pmd-size hugepages are not allowed. The code changes LGTM. > + if (hugepage_global_enabled()) > + return true; > + if (anon_hpage_pmd_enabled()) > + return true; > + if (shmem_hpage_pmd_enabled()) > return true; > return false; > }