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 A7AB1CCFA1A for ; Wed, 12 Nov 2025 02:37:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id A8DFC8E0008; Tue, 11 Nov 2025 21:37:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id A656C8E0003; Tue, 11 Nov 2025 21:37:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 9A1C68E0008; Tue, 11 Nov 2025 21:37:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 897058E0003 for ; Tue, 11 Nov 2025 21:37:18 -0500 (EST) Received: from smtpin08.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 15679577E8 for ; Wed, 12 Nov 2025 02:37:18 +0000 (UTC) X-FDA: 84100393356.08.8600C9C Received: from out-184.mta0.migadu.com (out-184.mta0.migadu.com [91.218.175.184]) by imf11.hostedemail.com (Postfix) with ESMTP id 3B62240003 for ; Wed, 12 Nov 2025 02:37:16 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=QbztwhPr; spf=pass (imf11.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.184 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762915036; 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=r9KeP80JkBLPDsPiZQ0VAhjwhtMuGyna7gI+eXyJJY4=; b=IfNgOS4DrOJEEIY8PqCvKjbZsANtVbgIPR5rAPALZOdUay0H8GdHK5cAMiAT9atDDBmimF 4/fqmhEbdp3rVelbSJoRSQaNIOgZEZJne1lmZY+PbmAFFri04v+KTScK6f8WR+92kvgfoY 3Xfb+08UvIsa4IglRiD9EOfiJaF31s0= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=QbztwhPr; spf=pass (imf11.hostedemail.com: domain of lance.yang@linux.dev designates 91.218.175.184 as permitted sender) smtp.mailfrom=lance.yang@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762915036; a=rsa-sha256; cv=none; b=10GkxwfmZRorDhSv9oGtMpusyRwX/13gj+3QtqprFbyle1HiEx+ohzdrWP71bmejWAyxhN EnvD0GDEGChosVU+/OYtUop6Cokva/HKkBosOXDEAtko/LiV1UNT8jgYO1kpZtv9czf/2z IYY6/RKOENwt/r0q83uVYJL5SQ5qqpE= Message-ID: <06096f8b-4da0-4b5c-af3c-fd8871437c16@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1762915034; h=from:from: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; bh=r9KeP80JkBLPDsPiZQ0VAhjwhtMuGyna7gI+eXyJJY4=; b=QbztwhPrnCHJ6w82sjuecGfn0Me5zhee6Y8JBBUvGYBhGgZmGKoW0Sq/zthgrGxDtzQV/h bN0Dj2FCuyrsHspziwiCby0+HULtYdQ3TufpS8ULa1UHzkgHPfKEvRxoQUKIVLh2bBYXrm yZhgnQBnQPxgldrvr6vffvW7WPBc/Dg= Date: Wed, 12 Nov 2025 10:37:06 +0800 MIME-Version: 1.0 Subject: Re: [PATCH] mm/khugepaged: continue to collapse on SCAN_PMD_NONE To: Wei Yang Cc: linux-mm@kvack.org, baolin.wang@linux.alibaba.com, dev.jain@arm.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, npache@redhat.com, baohua@kernel.org, akpm@linux-foundation.org, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com References: <20251112020031.25350-1-richard.weiyang@gmail.com> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <20251112020031.25350-1-richard.weiyang@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 3B62240003 X-Stat-Signature: o6s3io5hsiod4ixjwpp1m5sqfwn7jq6j X-Rspam-User: X-HE-Tag: 1762915036-783331 X-HE-Meta: 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 yOKxcrGm qs8BjzUTeoboXVndi0LSaVpDytmTdg6uUu6S3Q25o1/r54WkLwdQSdXSyi8QSPGteqC3jZEtbv812JYNdDlML6X8O2T+1ELLj7/9prcG68t7ycjQDUd9qg8io/En2UxxuCVnwFxLqtUzVv6pU7x2rV9/gG8WXcnGe+dQqoVqpi4uE42g1bc+v5rLJmbhmL6Sj+yz0pQGVwwviHFt2AdrWUmzeFR00BTe4sJzc2M5vo315cFTKqmUNgkVJslkZQLIvV9WmDujFqTxesAHsiwnqyeFIqnH87m0zAmicH564aGx7KLfpvPkoWJJpBQ== 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 2025/11/12 10:00, Wei Yang wrote: > SCAN_PMD_NONE means current pmd is empty, but we can still continue > collapse next pmd range. Right, bailing out of the whole MADV_COLLAPSE request just because we encounter one empty PMD is too strict ... It makes sense to treat SCAN_PMD_NONE like the other whitelisted cases (e.g., SCAN_PMD_NULL). > > Signed-off-by: Wei Yang > --- LGTM. Reviewed-by: Lance 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: