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=-15.3 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,USER_AGENT_SANE_1 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 9028DC43461 for ; Fri, 14 May 2021 01:53:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54A2161415 for ; Fri, 14 May 2021 01:53:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232196AbhENBzB (ORCPT ); Thu, 13 May 2021 21:55:01 -0400 Received: from szxga06-in.huawei.com ([45.249.212.32]:2662 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231154AbhENBy7 (ORCPT ); Thu, 13 May 2021 21:54:59 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4FhBMp3wV6zmW7n; Fri, 14 May 2021 09:51:34 +0800 (CST) Received: from [10.174.176.232] (10.174.176.232) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.498.0; Fri, 14 May 2021 09:53:42 +0800 Subject: Re: [PATCH v3 3/5] mm/huge_memory.c: add missing read-only THP checking in transparent_hugepage_enabled() To: Yang Shi CC: Andrew Morton , Zi Yan , , Matthew Wilcox , "Yang Shi" , , "Ralph Campbell" , Song Liu , "Kirill A. Shutemov" , Rik van Riel , Johannes Weiner , Minchan Kim , Hugh Dickins , , Linux Kernel Mailing List , Linux MM , Linux FS-devel Mailing List References: <20210511134857.1581273-1-linmiaohe@huawei.com> <20210511134857.1581273-4-linmiaohe@huawei.com> From: Miaohe Lin Message-ID: <178ec3ad-c6f6-465a-936e-992445b8c358@huawei.com> Date: Fri, 14 May 2021 09:53:42 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.232] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2021/5/14 5:30, Yang Shi wrote: > On Tue, May 11, 2021 at 6:49 AM Miaohe Lin wrote: >> >> Since commit 99cb0dbd47a1 ("mm,thp: add read-only THP support for >> (non-shmem) FS"), read-only THP file mapping is supported. But it >> forgot to add checking for it in transparent_hugepage_enabled(). >> To fix it, we add checking for read-only THP file mapping and also >> introduce helper transhuge_vma_enabled() to check whether thp is >> enabled for specified vma to reduce duplicated code. We rename >> transparent_hugepage_enabled to transparent_hugepage_active to make >> the code easier to follow as suggested by David Hildenbrand. >> >> Fixes: 99cb0dbd47a1 ("mm,thp: add read-only THP support for (non-shmem) FS") >> Signed-off-by: Miaohe Lin > > Looks correct to me. Reviewed-by: Yang Shi > Many thanks for your Reviewed-by tag. > Just a nit below: > >> --- >> fs/proc/task_mmu.c | 2 +- >> include/linux/huge_mm.h | 27 ++++++++++++++++++++------- >> mm/huge_memory.c | 11 ++++++++++- >> mm/khugepaged.c | 4 +--- >> mm/shmem.c | 3 +-- >> 5 files changed, 33 insertions(+), 14 deletions(-) >> >> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c >> index fc9784544b24..7389df326edd 100644 >> --- a/fs/proc/task_mmu.c >> +++ b/fs/proc/task_mmu.c >> @@ -832,7 +832,7 @@ static int show_smap(struct seq_file *m, void *v) >> __show_smap(m, &mss, false); >> >> seq_printf(m, "THPeligible: %d\n", >> - transparent_hugepage_enabled(vma)); >> + transparent_hugepage_active(vma)); >> >> if (arch_pkeys_enabled()) >> seq_printf(m, "ProtectionKey: %8u\n", vma_pkey(vma)); >> diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h >> index 0a526f211fec..a35c13d1f487 100644 >> --- a/include/linux/huge_mm.h >> +++ b/include/linux/huge_mm.h >> @@ -115,9 +115,19 @@ extern struct kobj_attribute shmem_enabled_attr; >> >> extern unsigned long transparent_hugepage_flags; >> >> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma, > > I'd like to have this function defined next to transhuge_vma_suitable(). > Sounds reasonable. Will do. Thanks! >> + unsigned long vm_flags) >> +{ >> + /* Explicitly disabled through madvise. */ >> + if ((vm_flags & VM_NOHUGEPAGE) || >> + test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) >> + return false; >> + return true; >> +} >> + >> /* >> * to be used on vmas which are known to support THP. >> - * Use transparent_hugepage_enabled otherwise >> + * Use transparent_hugepage_active otherwise >> */ >> static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) >> { >> @@ -128,15 +138,12 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) >> if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_NEVER_DAX)) >> return false; >> >> - if (vma->vm_flags & VM_NOHUGEPAGE) >> + if (!transhuge_vma_enabled(vma, vma->vm_flags)) >> return false; >> >> if (vma_is_temporary_stack(vma)) >> return false; >> >> - if (test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) >> - return false; >> - >> if (transparent_hugepage_flags & (1 << TRANSPARENT_HUGEPAGE_FLAG)) >> return true; >> >> @@ -150,7 +157,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) >> return false; >> } >> >> -bool transparent_hugepage_enabled(struct vm_area_struct *vma); >> +bool transparent_hugepage_active(struct vm_area_struct *vma); >> >> static inline bool transhuge_vma_suitable(struct vm_area_struct *vma, >> unsigned long haddr) >> @@ -351,7 +358,7 @@ static inline bool __transparent_hugepage_enabled(struct vm_area_struct *vma) >> return false; >> } >> >> -static inline bool transparent_hugepage_enabled(struct vm_area_struct *vma) >> +static inline bool transparent_hugepage_active(struct vm_area_struct *vma) >> { >> return false; >> } >> @@ -362,6 +369,12 @@ static inline bool transhuge_vma_suitable(struct vm_area_struct *vma, >> return false; >> } >> >> +static inline bool transhuge_vma_enabled(struct vm_area_struct *vma, >> + unsigned long vm_flags) >> +{ >> + return false; >> +} >> + >> static inline void prep_transhuge_page(struct page *page) {} >> >> static inline bool is_transparent_hugepage(struct page *page) >> diff --git a/mm/huge_memory.c b/mm/huge_memory.c >> index 76ca1eb2a223..4f37867eed12 100644 >> --- a/mm/huge_memory.c >> +++ b/mm/huge_memory.c >> @@ -63,7 +63,14 @@ static struct shrinker deferred_split_shrinker; >> static atomic_t huge_zero_refcount; >> struct page *huge_zero_page __read_mostly; >> >> -bool transparent_hugepage_enabled(struct vm_area_struct *vma) >> +static inline bool file_thp_enabled(struct vm_area_struct *vma) >> +{ >> + return transhuge_vma_enabled(vma, vma->vm_flags) && vma->vm_file && >> + !inode_is_open_for_write(vma->vm_file->f_inode) && >> + (vma->vm_flags & VM_EXEC); >> +} >> + >> +bool transparent_hugepage_active(struct vm_area_struct *vma) >> { >> /* The addr is used to check if the vma size fits */ >> unsigned long addr = (vma->vm_end & HPAGE_PMD_MASK) - HPAGE_PMD_SIZE; >> @@ -74,6 +81,8 @@ bool transparent_hugepage_enabled(struct vm_area_struct *vma) >> return __transparent_hugepage_enabled(vma); >> if (vma_is_shmem(vma)) >> return shmem_huge_enabled(vma); >> + if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS)) >> + return file_thp_enabled(vma); >> >> return false; >> } >> diff --git a/mm/khugepaged.c b/mm/khugepaged.c >> index 6c0185fdd815..d97b20fad6e8 100644 >> --- a/mm/khugepaged.c >> +++ b/mm/khugepaged.c >> @@ -442,9 +442,7 @@ static inline int khugepaged_test_exit(struct mm_struct *mm) >> static bool hugepage_vma_check(struct vm_area_struct *vma, >> unsigned long vm_flags) >> { >> - /* Explicitly disabled through madvise. */ >> - if ((vm_flags & VM_NOHUGEPAGE) || >> - test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) >> + if (!transhuge_vma_enabled(vma, vm_flags)) >> return false; >> >> /* Enabled via shmem mount options or sysfs settings. */ >> diff --git a/mm/shmem.c b/mm/shmem.c >> index a08cedefbfaa..1dcbec313c70 100644 >> --- a/mm/shmem.c >> +++ b/mm/shmem.c >> @@ -4032,8 +4032,7 @@ bool shmem_huge_enabled(struct vm_area_struct *vma) >> loff_t i_size; >> pgoff_t off; >> >> - if ((vma->vm_flags & VM_NOHUGEPAGE) || >> - test_bit(MMF_DISABLE_THP, &vma->vm_mm->flags)) >> + if (!transhuge_vma_enabled(vma, vma->vm_flags)) >> return false; >> if (shmem_huge == SHMEM_HUGE_FORCE) >> return true; >> -- >> 2.23.0 >> >> > . >