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 278F5C433F5 for ; Wed, 27 Oct 2021 21:32:18 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CEA0260F92 for ; Wed, 27 Oct 2021 21:32:17 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org CEA0260F92 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id 628196B0071; Wed, 27 Oct 2021 17:32:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5D6F46B0072; Wed, 27 Oct 2021 17:32:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4770C6B0073; Wed, 27 Oct 2021 17:32:17 -0400 (EDT) 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 2250C6B0071 for ; Wed, 27 Oct 2021 17:32:17 -0400 (EDT) Received: from smtpin26.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id AA38F181CC1A8 for ; Wed, 27 Oct 2021 21:32:16 +0000 (UTC) X-FDA: 78743515872.26.0E83653 Received: from mail-ed1-f50.google.com (mail-ed1-f50.google.com [209.85.208.50]) by imf06.hostedemail.com (Postfix) with ESMTP id 5598B801A8A7 for ; Wed, 27 Oct 2021 21:32:16 +0000 (UTC) Received: by mail-ed1-f50.google.com with SMTP id g8so16402337edb.2 for ; Wed, 27 Oct 2021 14:32:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0eLs1vKCdD9fRUqUY5RcYH11tOWYmTj/mhP+WyCuSws=; b=bFn4mtu1GV4VL42GOaedj6+RTGWTSaRL10vA5lMTwhC9f/TSuaIgj4vt/kiSeQ0OG6 fZ7xUcbnD42u3FPpAML/7jbHVZRVs5vYJ4dG/COcZsYuLhtJLwRuOT6RklhqOYU3xSwC LF6rdT+paQcIxhvWydHu3rpYUCbUgg+WGJWKx+9zyL4N1RD8BRrrT6omtw9lbGPHT0ui fAZvCDSwqDILwokQeYTIqPvq6xNGHPoF4xkS4cHJnY6kWyqnENKL2pVuAR6Xj/tiOdya 8vGdaBx8VAVmMLjuT1/uh+3Vqb0cy73hZ2kpPm/es7QPo7SaiToP7Y3/HVXL1I9gMeXx tIsg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0eLs1vKCdD9fRUqUY5RcYH11tOWYmTj/mhP+WyCuSws=; b=0x2wa5U/N+ikGUgwgqna9vwUG/ou/JFzQZirPu94MrNFYECHn1L8MTY3hs6uJzJify qTpAqzG5LGd7SsVn9/f6edeE9tZ1sJg/IuwpgDpbhnCMJY9lDaWWCWWIyG4chcEjg8OD n2l4YpmC6tXY39wg4FZJ3dmGxiFtVcVy4ZembzOgWgRa0mNQBQLd37I+MlA/s7sgsx6A 0wE5Om7DYjYFPNihwIuy42Ol7zQ1+zhoAUiigb14bCIk40gdDiH3nyZzCfQOYlaMA8Lw zxi5Mv5/cxIKvbbEncruIfZ3C+zw03TIjWv3SpFYsdZSiqPTLmq/QHBB121z5h0RtkW2 B3HA== X-Gm-Message-State: AOAM533b7q8iJGXl0RoSt8WpijE18jNLWDcYednNoWzG6TEVDcVc3LHH hshVUH7wIITngNvOw2FdNRpRtFVzU5fZIHGT/2w= X-Google-Smtp-Source: ABdhPJxi08ueX1uJIQi3nNiPcLn92zuct9e+mWkRd0nfv01nssBA6LRbHDXqZtemi0VUtjzqzBhq3Z7fF4/sGrBMX7c= X-Received: by 2002:a50:8d52:: with SMTP id t18mr489479edt.71.1635370334982; Wed, 27 Oct 2021 14:32:14 -0700 (PDT) MIME-Version: 1.0 References: <20211027195221.3825-1-shy828301@gmail.com> In-Reply-To: From: Yang Shi Date: Wed, 27 Oct 2021 14:32:02 -0700 Message-ID: Subject: Re: [PATCH] mm: khugepaged: skip huge page collapse for special files To: Matthew Wilcox Cc: Hugh Dickins , Hao Sun , "Kirill A. Shutemov" , Song Liu , Andrea Righi , Andrew Morton , Linux MM , Linux Kernel Mailing List , stable Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 5598B801A8A7 X-Stat-Signature: pfnrrakj3q3zxe8c7wzjsiwaossdzun4 Authentication-Results: imf06.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=bFn4mtu1; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf06.hostedemail.com: domain of shy828301@gmail.com designates 209.85.208.50 as permitted sender) smtp.mailfrom=shy828301@gmail.com X-HE-Tag: 1635370336-22128 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 Wed, Oct 27, 2021 at 1:50 PM Matthew Wilcox wrote: > > 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. Yes, Song mentioned the same thing. Fixed by an incremental patch. > > > /* 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 > >