From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 D9CEA2F3639 for ; Mon, 8 Sep 2025 09:28:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757323689; cv=none; b=s79mLt7fewZi7s3UGn/K3i/yNNlnsB8s3LUKcRLWMlB4z507Rd7PKMDmGrcVbfpS0O2Sn7yRGVA6DnoyQMZAuq9u+9KVtT8IGZ8c/JnTDS5lY2wqLUyRk3hiADcn+PRDj4Obq/R9ibghlLtStMxFj8rtvzpremy0k8GyTHB7FNk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757323689; c=relaxed/simple; bh=9Yc350bOoXWQnnKCxgDF3bTAxz3r3C7tm41X5x1rijg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=io4XHtnXd6BTfqMN68fHausSFQUzIc9vZIFg+mc2K6lBEhBbDAjrKZSHGy7RHvc4WcGCXF/5a7qMwgVW16gWFArCir1GsJv5+2KUNHPHQPJAzG9v1F1Xehs2Ff3n/kHBNUSnB+SsRQJa+r+uTVcRozEEvi0ETkB4nCNcorFDO9c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=YKK4rjvH; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="YKK4rjvH" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1757323682; 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=l9h4BcOvxOwjHrG9H029E2+yuGVDQtSI0hF0Jbh8AA8=; b=YKK4rjvHR8VZawK48xv2K7mntDx6rWV7+SqBIHraZETqNuF8fOfhd4Y2sdUoiQqY2YB+jk mNgxRaoD3QRENGOklPO0EtqdTQxLshJhKJCMQLZfOR+5Nm5xMK2QlD7dGJiIZlv6NAgbag s8hbCIzzfMwZpwZTUYQinBbGyesZdBE= Date: Mon, 8 Sep 2025 17:27:51 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2 1/1] mm: skip mlocked THPs that are underused early in deferred_split_scan() Content-Language: en-US To: David Hildenbrand Cc: Liam.Howlett@oracle.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, dev.jain@arm.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, lorenzo.stoakes@oracle.com, npache@redhat.com, ryan.roberts@arm.com, usamaarif642@gmail.com, ziy@nvidia.com, akpm@linux-foundation.org References: <20250908090741.61519-1-lance.yang@linux.dev> <73c8a52c-37c5-45f4-b76e-f15267412242@redhat.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Lance Yang In-Reply-To: <73c8a52c-37c5-45f4-b76e-f15267412242@redhat.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 2025/9/8 17:12, David Hildenbrand wrote: > On 08.09.25 11:07, Lance Yang wrote: >> From: Lance Yang >> >> When we stumble over a fully-mapped mlocked THP in the deferred shrinker, >> it does not make sense to try to detect whether it is underused, because >> try_to_map_unused_to_zeropage(), called while splitting the folio, >> will not >> actually replace any zeroed pages by the shared zeropage. >> >> Splitting the folio in that case does not make any sense, so let's not >> even >> scan to check if the folio is underused. >> >> Suggested-by: David Hildenbrand > > Feel free to drop that, I only tweaked you description :) Well, I'd actually prefer to keep it. Thanks for setting me straight on try_to_map_unused_to_zeropage() ;p > > Acked-by: David Hildenbrand Cheers, Lance