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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 EDBFBC63697 for ; Thu, 26 Nov 2020 17:18:33 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 766C921D1A for ; Thu, 26 Nov 2020 17:18:33 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 766C921D1A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.cz Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id E1A746B0073; Thu, 26 Nov 2020 12:18:32 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id DC9DD6B0074; Thu, 26 Nov 2020 12:18:32 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id CB99C6B0078; Thu, 26 Nov 2020 12:18:32 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0144.hostedemail.com [216.40.44.144]) by kanga.kvack.org (Postfix) with ESMTP id B5A2C6B0073 for ; Thu, 26 Nov 2020 12:18:32 -0500 (EST) Received: from smtpin07.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 851051EE6 for ; Thu, 26 Nov 2020 17:18:32 +0000 (UTC) X-FDA: 77527228464.07.sense96_400605f27381 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin07.hostedemail.com (Postfix) with ESMTP id 662B01803FFC1 for ; Thu, 26 Nov 2020 17:18:32 +0000 (UTC) X-HE-Tag: sense96_400605f27381 X-Filterd-Recvd-Size: 4616 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf06.hostedemail.com (Postfix) with ESMTP for ; Thu, 26 Nov 2020 17:18:31 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id C9506AC2D; Thu, 26 Nov 2020 17:18:30 +0000 (UTC) Subject: Re: [PATCH 3/3] mm,thp,shmem: make khugepaged obey tmpfs mount flags To: Rik van Riel , hughd@google.com Cc: xuyu@linux.alibaba.com, akpm@linux-foundation.org, mgorman@suse.de, aarcange@redhat.com, willy@infradead.org, linux-kernel@vger.kernel.org, kernel-team@fb.com, linux-mm@kvack.org, mhocko@suse.com References: <20201124194925.623931-1-riel@surriel.com> <20201124194925.623931-4-riel@surriel.com> From: Vlastimil Babka Message-ID: Date: Thu, 26 Nov 2020 18:18:29 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.5.0 MIME-Version: 1.0 In-Reply-To: <20201124194925.623931-4-riel@surriel.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit 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: On 11/24/20 8:49 PM, Rik van Riel wrote: > Currently if thp enabled=[madvise], mounting a tmpfs filesystem > with huge=always and mmapping files from that tmpfs does not > result in khugepaged collapsing those mappings, despite the > mount flag indicating that it should. > > Fix that by breaking up the blocks of tests in hugepage_vma_check > a little bit, and testing things in the correct order. > > Signed-off-by: Rik van Riel > Fixes: c2231020ea7b ("mm: thp: register mm for khugepaged when merging vma for shmem") Looks ok. But, it we have sysfs thp enabled=never, and shmem mount explicitly thp enabled, then shmem mount overrides the global sysfs setting and thp's will be allocated there, right? However, khugepaged_enabled() will be false and thus khugepaged won't run at all? So a similar situation than what you're fixing here. > --- > include/linux/khugepaged.h | 2 ++ > mm/khugepaged.c | 22 ++++++++++++++++------ > 2 files changed, 18 insertions(+), 6 deletions(-) > > diff --git a/include/linux/khugepaged.h b/include/linux/khugepaged.h > index c941b7377321..2fcc01891b47 100644 > --- a/include/linux/khugepaged.h > +++ b/include/linux/khugepaged.h > @@ -3,6 +3,7 @@ > #define _LINUX_KHUGEPAGED_H > > #include /* MMF_VM_HUGEPAGE */ > +#include > > > #ifdef CONFIG_TRANSPARENT_HUGEPAGE > @@ -57,6 +58,7 @@ static inline int khugepaged_enter(struct vm_area_struct *vma, > { > if (!test_bit(MMF_VM_HUGEPAGE, &vma->vm_mm->flags)) > if ((khugepaged_always() || > + (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) || > (khugepaged_req_madv() && (vm_flags & VM_HUGEPAGE))) && > !(vm_flags & VM_NOHUGEPAGE) && > !test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 4e3dff13eb70..abab394c4206 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -440,18 +440,28 @@ static inline int khugepaged_test_exit(struct mm_struct *mm) > static bool hugepage_vma_check(struct vm_area_struct *vma, > unsigned long vm_flags) > { > - if ((!(vm_flags & VM_HUGEPAGE) && !khugepaged_always()) || > - (vm_flags & VM_NOHUGEPAGE) || > + /* Explicitly disabled through madvise. */ > + if ((vm_flags & VM_NOHUGEPAGE) || > test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) > return false; > > - if (shmem_file(vma->vm_file) || > - (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && > - vma->vm_file && > - (vm_flags & VM_DENYWRITE))) { > + /* Enabled via shmem mount options or sysfs settings. */ > + if (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) { > return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff, > HPAGE_PMD_NR); > } > + > + /* THP settings require madvise. */ > + if (!(vm_flags & VM_HUGEPAGE) && !khugepaged_always()) > + return false; > + > + /* Read-only file mappings need to be aligned for THP to work. */ > + if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file && > + (vm_flags & VM_DENYWRITE)) { > + return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff, > + HPAGE_PMD_NR); > + } > + > if (!vma->anon_vma || vma->vm_ops) > return false; > if (vma_is_temporary_stack(vma)) >