From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 62A5D23C8C7; Thu, 11 Jun 2026 12:11:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.113 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781179881; cv=none; b=setHW9blc2uTYfonWV/l/zjHyT8BhPDF2mO1lpakSzxhkRA0JyPZiKUIKQrVTOtHqv7a4w61dHVUvgDWowF1rxtNVhPMCbZjLhI+H76BXbvtqOS1ZUuU84d78izTBkOVYMXSMgfP1GKlWHadhyxzafw5cD3oMVtTCCr5LGUD2W8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781179881; c=relaxed/simple; bh=0IngIz8OzkiyvyhyV1yjPJzS/gHOpsG3BVGc5FS3Y/A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AwKDNMA+3TKkG1TLNfgQp6Yy4Et0K76n+4/D93Yp2xoWetfd7JvcC//zDV/KXjhvE/sC8soz7XrNvHt3NbiOcnGWRYNHD7ykLGh/cN6/3Cc1qLLm3o/R/wbxvOKiF0uQKpR5NzXKnkwd6uQMX7UvU3r7wMqolN0RTG9rU811dBo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=kXDbOG7k; arc=none smtp.client-ip=115.124.30.113 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="kXDbOG7k" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1781179871; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=+gAUjXbMGZfUSgaQOzcFV/0TYnRK9QhUgm1Vyadp9F0=; b=kXDbOG7kfp1OHS5IEnU9JGyRWxO0Vtrd8QsQVnEdPDr2MU/IQT4ng+q5DX+ycnAHZy5CAXZDHyLhTFNdKuJUhkOZZ5wppdD0tkUnEzbkqzMWhF6J2llbSzpvWJMZdlm0W3HpJ3pFRk/uHqx0Hu7IsIy2nIIArK1aNfeOTd/lbVE= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033037033178;MF=baolin.wang@linux.alibaba.com;NM=1;PH=DS;RN=15;SR=0;TI=SMTPD_---0X4dcBhE_1781179868; Received: from 30.120.38.205(mailfrom:baolin.wang@linux.alibaba.com fp:SMTPD_---0X4dcBhE_1781179868 cluster:ay36) by smtp.aliyun-inc.com; Thu, 11 Jun 2026 20:11:09 +0800 Message-ID: Date: Thu, 11 Jun 2026 20:11:08 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH v2 04/11] mm: khugepaged: add shmem mTHP collapse support To: Lance Yang Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, hughd@google.com, willy@infradead.org, ziy@nvidia.com, liam@infradead.org, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <3895c09794739bbfae99d9e021ffacf8a51fb8e2.1781083630.git.baolin.wang@linux.alibaba.com> <20260611060619.94738-1-lance.yang@linux.dev> From: Baolin Wang In-Reply-To: <20260611060619.94738-1-lance.yang@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 6/11/26 2:06 PM, Lance Yang wrote: > > On Wed, Jun 10, 2026 at 06:29:12PM +0800, Baolin Wang wrote: > [...] >> @@ -2768,15 +2827,23 @@ static enum scan_result collapse_scan_file(struct mm_struct *mm, >> else >> cc->progress += HPAGE_PMD_NR; >> >> - if (result == SCAN_SUCCEED) { >> - if (present < HPAGE_PMD_NR - max_ptes_none) { >> - result = SCAN_EXCEED_NONE_PTE; >> - count_vm_event(THP_SCAN_EXCEED_NONE_PTE); >> - } else { >> - result = collapse_file(mm, addr, file, start, cc, HPAGE_PMD_ORDER); >> - } >> + if (result != SCAN_SUCCEED) >> + goto out; >> + >> + if (present < HPAGE_PMD_NR - max_ptes_none) { >> + result = SCAN_EXCEED_NONE_PTE; >> + count_vm_event(THP_SCAN_EXCEED_NONE_PTE); >> + count_mthp_stat(HPAGE_PMD_ORDER, >> + MTHP_STAT_COLLAPSE_EXCEED_NONE); >> + goto out; >> } >> >> + result = mthp_collapse(mm, file, start, addr, 0, 0, cc, enabled_orders); > > Feels like the second 0 wants to be "swap", no? It seems so. This reminds me of the issue you’re trying to fix in [1]. [1] https://lore.kernel.org/all/20260609120443.71864-1-lance.yang@linux.dev/