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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A68B5CCFA1E for ; Wed, 12 Nov 2025 09:51:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id E881A8E0005; Wed, 12 Nov 2025 04:51:17 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E38CA8E0002; Wed, 12 Nov 2025 04:51:17 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D4E568E0005; Wed, 12 Nov 2025 04:51:17 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id C44208E0002 for ; Wed, 12 Nov 2025 04:51:17 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 0FD8512D048 for ; Wed, 12 Nov 2025 09:51:17 +0000 (UTC) X-FDA: 84101486994.14.A204C0B Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf10.hostedemail.com (Postfix) with ESMTP id 4B3FDC000B for ; Wed, 12 Nov 2025 09:51:15 +0000 (UTC) Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=cGF0bBQ5; spf=pass (imf10.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762941075; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=CAJa9W3VI9OuEv7/qMBL0f9nyMqovTpBV8OIF7uksmc=; b=uJSoVai/Skre63Ls+5lFXUWkCuteoOdSYlh4inMisdoQ7WAzz4g/5JU0dLupEPooa3UOwn bHJ3a1J5gMgVgt9btvdOgSWu3OCMcEsDMu1hD4r3zgV5ZMQmtcojQXlxCk/7Y7APtwpqIm UodsAyTGy+b7Oz+KPXVRu7mgHc9bzO4= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762941075; a=rsa-sha256; cv=none; b=CIrJoh7CH+8Pm5f2s1t8u9hvqd8lK/NEi1JWXXSurPgTRQmLIteXKT0Hsh09lbXObrdym1 Hy8+jaMx40c2+31ReJKDXo7s/gv6OkLvLyLJo9PHSdR/r1wK2kohcqVR+7qSS0GtPZWIcm fKmIhouxW2A+MnSIROlV+DodBZBacSs= ARC-Authentication-Results: i=1; imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=cGF0bBQ5; spf=pass (imf10.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 0FAFD40890; Wed, 12 Nov 2025 09:51:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A205DC4CEF7; Wed, 12 Nov 2025 09:51:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762941073; bh=5DNNIM5JOi3pB9R75Cu9kw/Z1+FNw7/8QVM0PNSGv8U=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=cGF0bBQ5POHNgluCLqf1ESBgAEJqHROfJwHuFD4B6zmrjJgnMU9n+Gz4XX0D3zSrR +ZRdm8hKsqyq1zYytBgQROhLkGiznpz0fEC25iRRJXnmO+VFMyYmcCf1Hw4ywl1NiU rdTVDfI5JKLeQ2eMlnF+qDKl+KH1qGeBJ4dO7EpdAx7MbeGZLcdgTeH9c/OwfP893k BQtVJJfph1nAiiWXG47QXZM6ZVctOgsF++eqV9X2ecapCmJROoya6dTLrglophQM1k 7H2rYbMLHjRR1S4maWi04YHY3Tt1+S2BpjNzWvmRikHk5vuhzqYxOWmwYKpMqNVO0f q+Lg8Z+SUD+Wg== Message-ID: <04e8e813-b43b-423e-8ad9-fb13ac953055@kernel.org> Date: Wed, 12 Nov 2025 10:51:09 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/khugepaged: continue to collapse on SCAN_PMD_NONE To: Wei Yang , akpm@linux-foundation.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, baolin.wang@linux.alibaba.com, Liam.Howlett@oracle.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev Cc: linux-mm@kvack.org References: <20251112020031.25350-1-richard.weiyang@gmail.com> From: "David Hildenbrand (Red Hat)" Content-Language: en-US In-Reply-To: <20251112020031.25350-1-richard.weiyang@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Stat-Signature: n7999pzq8f9su16poj59pskazfzegyo3 X-Rspam-User: X-Rspamd-Queue-Id: 4B3FDC000B X-Rspamd-Server: rspam01 X-HE-Tag: 1762941075-763055 X-HE-Meta: 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 4xDvCOsO Dn4+m0Xqs40CSII7VFM3DgEQhraAqE2a7JS3QN4jzRBjMt//8AgrndriJrjauq9NSLy6xWUT5qBGFce7RIAORh7pj1H2vxEDWl7IXm5oW1sFmlf0NdPUcLrq2WshODUshmX2LFqc+Qihd5J62ojflGxGrnBwPH55Cchz4DdF0XCHfx8b9Sf4e+Sou1X5Q0VS5F4JNtxwWe57ATd7OiHWya+iPPUPS+qv7qP/tjj369j8wkaIREVBQjMS4ShDCT2vj5Z4bA0njlF/rGXR2Kag6iUxpGGgQExofnGjDNqDMFFfc6iwmk0PRyVDx3agkeDee6SjGpvXWSNGEg4xOOhpG30oqv/hNbmQ1eusqCAppYusT41UIi4al/1oiTZrjYT3XjPkas1ZnTNBxwk9yGK73YPyyeg== 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: List-Subscribe: List-Unsubscribe: On 12.11.25 03:00, Wei Yang wrote: > SCAN_PMD_NONE means current pmd is empty, but we can still continue > collapse next pmd range. > > Signed-off-by: Wei Yang > --- > mm/khugepaged.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/khugepaged.c b/mm/khugepaged.c > index 7e8cb181d5bd..4c2217076ad3 100644 > --- a/mm/khugepaged.c > +++ b/mm/khugepaged.c > @@ -2835,6 +2835,7 @@ int madvise_collapse(struct vm_area_struct *vma, unsigned long start, > goto handle_result; > /* Whitelisted set of results where continuing OK */ > case SCAN_PMD_NULL: > + case SCAN_PMD_NONE: > case SCAN_PTE_NON_PRESENT: > case SCAN_PTE_UFFD_WP: > case SCAN_LACK_REFERENCED_PAGE: Looks ok to me. I am really confused about PMD_NONE vs. PMD_NULL. Is my understanding correct, hat with your patch we can just merge both into a single NO_PMD_TABLE or sth. like that? -- Cheers David