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 F216DC433EF for ; Wed, 27 Oct 2021 21:57:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 711F360462 for ; Wed, 27 Oct 2021 21:57:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 711F360462 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 AF03A6B0073; Wed, 27 Oct 2021 17:57:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A78F2940007; Wed, 27 Oct 2021 17:57:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 941626B0075; Wed, 27 Oct 2021 17:57:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0125.hostedemail.com [216.40.44.125]) by kanga.kvack.org (Postfix) with ESMTP id 6BA266B0073 for ; Wed, 27 Oct 2021 17:57:18 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id DA87D39B1D for ; Wed, 27 Oct 2021 21:57:17 +0000 (UTC) X-FDA: 78743578914.17.47DE970 Received: from mail-ed1-f51.google.com (mail-ed1-f51.google.com [209.85.208.51]) by imf02.hostedemail.com (Postfix) with ESMTP id DA4617001715 for ; Wed, 27 Oct 2021 21:57:13 +0000 (UTC) Received: by mail-ed1-f51.google.com with SMTP id h7so16671902ede.8 for ; Wed, 27 Oct 2021 14:57:17 -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=CQvz9TZ32Kb1GiUC4FEdq67vGwshSMFaVjEepIS/INM=; b=RoO9FhMQ8yYJoBfZ0JQBmnbifXJac/BkLqpWrskN56Rbm1FWLdlVQfNAqhe2ajS8CH CZYVCQ7/SwIM8BPMXCO5gjDKL+GJxyWXj6Dw+8wHhv6vA0lJpqkRraY2z2hcE/NrMP1n vP4i71PWu1LeZVIS3XjlEUyabkuvTCBRxsCtKz4IBTq0ZoLSMidRCRwQuaGOHu3rKg9Y w068GC8MwKfinEIf/doBe4Kv4Oow+r0cwghH9Alq6u3FGzu9iAaMFQd37vYdhGqVZbtq m+GAyUMcjgMuVzn1wu/qsPtW+lsf0n6ny1K1MPbqVFpt07DAp83QUEc7gvwjVqgLdhtn TT7w== 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=CQvz9TZ32Kb1GiUC4FEdq67vGwshSMFaVjEepIS/INM=; b=MUGX1/nGlPDLqzgpblzteicR1J1s6AOICPosCqehXMj89s/D5fm/t2t9eKgoa9wm6R M1PGIKSi0ix4u5ZNAxX8TU4ipP1TvB1zBh8YMy42AV5u5RrjEME5fm0yTbjkeRVk3cIB 3R6dG4bEx/eJXoxxce7oIR5UsQS/vIar7qcT+0wIHBjv9aFoJkOAk4pYNuBgok0PazUa JD3A69zmCK9CmcpunCQV0zKJv1hnk82pEaay+FuYNiAA3bfLYTtGvlbJF7CP92TPQSow FM5mO7MUGoLIeY1KG+QI7uuqhlN2OkyyuF3KmyHkkUxpJhdqC1VUl2U1ZcFWNgN6Mc0v 1DsA== X-Gm-Message-State: AOAM530XOftSuh6zigqbyJZPK+CIf6HhLdRxwFNIHOd9EvZcqiEiCnKz 6vygVeaM8FkB80P2Tc2et+H7UCJKqq7GQ0MYEa8= X-Google-Smtp-Source: ABdhPJy5Nn9hv5MsR/7yZbB39z5wO1SNl60QIQ1yDLfDZ+UfKPZ5n64Ov/EgNY5rwTCyZlMKH1d3hWr4bYZqap1MQ8U= X-Received: by 2002:a17:906:3f83:: with SMTP id b3mr227956ejj.233.1635371836131; Wed, 27 Oct 2021 14:57:16 -0700 (PDT) MIME-Version: 1.0 References: <20211027195221.3825-1-shy828301@gmail.com> <20211027135328.001e4582a9535e8e4be785bb@linux-foundation.org> In-Reply-To: <20211027135328.001e4582a9535e8e4be785bb@linux-foundation.org> From: Yang Shi Date: Wed, 27 Oct 2021 14:57:04 -0700 Message-ID: Subject: Re: [PATCH] mm: khugepaged: skip huge page collapse for special files To: Andrew Morton Cc: Song Liu , Hugh Dickins , "sunhao.th@gmail.com" , Matthew Wilcox , "Kirill A. Shutemov" , "andrea.righi@canonical.com" , Linux Memory Management List , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DA4617001715 X-Stat-Signature: 3ae1xt38gwhidt1awdckcx6uatyggdjy Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=RoO9FhMQ; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf02.hostedemail.com: domain of shy828301@gmail.com designates 209.85.208.51 as permitted sender) smtp.mailfrom=shy828301@gmail.com X-HE-Tag: 1635371833-107538 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 1:53 PM Andrew Morton wrote: > > On Wed, 27 Oct 2021 13:44:37 -0700 Yang Shi wrote: > > > > > --- a/mm/khugepaged.c > > > > +++ 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); > > > > > > Am I misreading this? If we return here for vma->vm_file, the following > > > logic (shmem_file(), etc.) would be skipped, no? > > > > Oh, yes, you are right. My mistake. > > > > Andrew, > > > > Could you please apply the below fix? > > um, how well tested are these changes? I has this fix on my test machine, but somehow forgot to fold it into the original patch. The whole fix was tested by opening /dev/nullb0 readonly and mapping with PROT_EXEC, the THP was not collapsed anymore.