From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from outbound-smtp38.blacknight.com (outbound-smtp38.blacknight.com [46.22.139.221]) (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 19F4C7FE for ; Thu, 1 Feb 2024 10:37:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=46.22.139.221 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706783873; cv=none; b=ChI0mdSNxsL7f/1y5GbV5lyRUdoSIJe0cdPNgD8CvwhSqndh5skzurzsG1P6/HzlxqOW0PznqPUyR+d7rF2uI+C3sUw4lbYo+zjDbhmiTsHjnx6OftzPY5yfJLHDrkYQJ5cJY1WHd8BeCFHNdbYX+Tuu8Sbg8D+GoACrEIc3r5I= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706783873; c=relaxed/simple; bh=R5jSD8/Z785gfYrTYHGHMJuVPRERQPN9G6HG8mAZauU=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=HTKH/dvEAc04S17BnSIyPheT+wKP1ozLoBonLnu6CQcxfL9cYdoCZylQVcyc4Hmz8I+q+mGB8T0fLLnCk5PqTqzqwyaNu52Zs+Bf3s42PZ+cbr0hUeSpg71c8GopcMy5k4x5SOJllGPFHisqAiPcL+xNgeB2MEzn/4f0jzoKMgo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net; spf=pass smtp.mailfrom=techsingularity.net; arc=none smtp.client-ip=46.22.139.221 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=techsingularity.net Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=techsingularity.net Received: from mail.blacknight.com (pemlinmail05.blacknight.ie [81.17.254.26]) by outbound-smtp38.blacknight.com (Postfix) with ESMTPS id 5C6F02436 for ; Thu, 1 Feb 2024 10:29:56 +0000 (GMT) Received: (qmail 434 invoked from network); 1 Feb 2024 10:29:56 -0000 Received: from unknown (HELO mail.blacknight.com) (mgorman@techsingularity.net@[81.17.254.19]) by 81.17.254.26 with ESMTPA; 1 Feb 2024 10:29:56 -0000 Date: Thu, 1 Feb 2024 10:29:54 +0000 From: Mel Gorman To: Baolin Wang Cc: akpm@linux-foundation.org, vbabka@suse.cz, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mm: compaction: limit the suitable target page order to be less than cc->order Message-ID: <20240201102954.e65g2q3twdtxhjzc@techsingularity.net> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: On Mon, Jan 22, 2024 at 09:01:53PM +0800, Baolin Wang wrote: > It can not improve the fragmentation if we isolate the target free pages > exceeding cc->order, especially when the cc->order is less than pageblock_order. > For example, suppose the pageblock_order is MAX_ORDER (size is 4M) and cc->order > is 2M THP size, we should not isolate other 2M free pages to be the migration > target, which can not improve the fragmentation. > > Moreover this is also applicable for large folio compaction. > > Signed-off-by: Baolin Wang Acked-by: Mel Gorman -- Mel Gorman SUSE Labs