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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C3D17C433F5 for ; Wed, 27 Oct 2021 20:51:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A3C806109E for ; Wed, 27 Oct 2021 20:51:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244059AbhJ0UyH (ORCPT ); Wed, 27 Oct 2021 16:54:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47520 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238909AbhJ0UyF (ORCPT ); Wed, 27 Oct 2021 16:54:05 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1E0D2C061570; Wed, 27 Oct 2021 13:51:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=FiTQfhf7kiYlnEK4FiYcuF1761gX6clAJ3pCzbAqESo=; b=pRkShx82edBCcyAY0tSmONxeVF Yjat2g8mUysN0x/aiN19JVZTmGGS7XUAu5auXz6P1Kd3G9nYYNaUSekcE5j/FqUry52AWdkkVFZCJ 7ndc2IkBv+THL6+/F/tj1HnmTtnUxI9euPMNvh0KNVGxk/D03Wp5xjuXIYBhYEW0XycwzlvEdLuGd Z+c9jbOsYMnxJaXwq5ZBjb3byZgDSHmniLFp6RAH86+WivU6qE81GKgo+6jgXW8W8OnwLuU8JiPL7 +MO4Vx7nKCmmKzIchnsDLBZutElvckNaFNg+Fr77Z0CGlhAkgGSYYNiLRgpuS5hN42ILNtReC7qhl 19BwW3Ag==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mfpsO-000JRN-Nm; Wed, 27 Oct 2021 20:50:30 +0000 Date: Wed, 27 Oct 2021 21:50:24 +0100 From: Matthew Wilcox To: Yang Shi Cc: hughd@google.com, sunhao.th@gmail.com, kirill.shutemov@linux.intel.com, songliubraving@fb.com, andrea.righi@canonical.com, akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] mm: khugepaged: skip huge page collapse for special files Message-ID: References: <20211027195221.3825-1-shy828301@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20211027195221.3825-1-shy828301@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 27, 2021 at 12:52:21PM -0700, Yang Shi wrote: > +++ b/mm/khugepaged.c > @@ -445,22 +445,25 @@ static bool hugepage_vma_check(struct vm_area_struct *vma, > if (!transhuge_vma_enabled(vma, vm_flags)) > return false; > > - /* Enabled via shmem mount options or sysfs settings. */ > - if (shmem_file(vma->vm_file) && shmem_huge_enabled(vma)) { > + if (vma->vm_file) > return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff, > HPAGE_PMD_NR); > - } > + > + /* Enabled via shmem mount options or sysfs settings. */ > + if (shmem_file(vma->vm_file)) > + return shmem_huge_enabled(vma); This doesn't make sense to me. if vma->vm_file, we already returned, so this is dead code. > /* 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. */ > + /* Only regular file is valid */ > if (IS_ENABLED(CONFIG_READ_ONLY_THP_FOR_FS) && vma->vm_file && > - !inode_is_open_for_write(vma->vm_file->f_inode) && > (vm_flags & VM_EXEC)) { > - return IS_ALIGNED((vma->vm_start >> PAGE_SHIFT) - vma->vm_pgoff, > - HPAGE_PMD_NR); > + struct inode *inode = vma->vm_file->f_inode; > + > + return !inode_is_open_for_write(inode) && > + S_ISREG(inode->i_mode); > } > > if (!vma->anon_vma || vma->vm_ops) > -- > 2.26.2 >