From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-98.freemail.mail.aliyun.com (out30-98.freemail.mail.aliyun.com [115.124.30.98]) (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 6CD7A1E0083 for ; Tue, 8 Jul 2025 01:14:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.98 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751937256; cv=none; b=ANgHSvI/Lgb8262tmVzN4wobp15EZVLmedCeEym16vJiRRKY7CTiErkoAMyFBP76MYpA8DQ+3krPRiBo4m9mv3R27eQBz9PrWXutzFrUHx0Lze6b6lj8GvMd36sBXQzPeAXic/8tFe9Th02SDZLhx++IgPNF5D9j/aDYJ/h7Nbg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751937256; c=relaxed/simple; bh=YwPaOS5x2EKb8tK1pFEOHeYDlHV/6GGZzy/egOu7TaY=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=CGnHlbOU06ooNKj1TaQp4292maS3GGYBpQ0JOWxMwnKAJcjt15QMkYLpf8+33muU/SUrYH0ic/FY+4pU+iAOLXhxVQTtqdB67sQR3drqhQ+vf3Q1NojZy/HxESm4jI0Qt+g637zqE5f9p/xWZQZ4ogtPDdfEVGGtKyko7XeCEq4= 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=hSXvYdwi; arc=none smtp.client-ip=115.124.30.98 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="hSXvYdwi" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1751937250; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=81k2TnA3ySuIrcjJ0C2twsaCPzS1HHoYg9nA+iYe+As=; b=hSXvYdwi87kyF07xumYFfzevEth82QdjlkUhNXqWXLW8FeQhQDteTFybWuhQEUjFJlIA/OwXOWP2khEnOv1sNw6iO5D0X+5IpNH+9d7DwFTVPE4HT4GtsHaqBkopTFdGn+ZUQLYoU+h3VA+9vXPEljxvIZIppGC/0Gk994EfY64= Received: from DESKTOP-5N7EMDA(mailfrom:ying.huang@linux.alibaba.com fp:SMTPD_---0WiIL1OC_1751937247 cluster:ay36) by smtp.aliyun-inc.com; Tue, 08 Jul 2025 09:14:08 +0800 From: "Huang, Ying" To: "Zhijian Li (Fujitsu)" Cc: "linux-mm@kvack.org" , "Huang, Ying" , "akpm@linux-foundation.org" , "linux-kernel@vger.kernel.org" , "Yasunori Gotou (Fujitsu)" , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , "lkp@intel.com" Subject: Re: [PATCH RFC v2] mm: memory-tiering: Fix PGPROMOTE_CANDIDATE accounting In-Reply-To: (Zhijian Li's message of "Mon, 30 Jun 2025 02:11:30 +0000") References: <20250625021352.2291544-1-lizhijian@fujitsu.com> Date: Tue, 08 Jul 2025 09:14:06 +0800 Message-ID: <87tt3nxz4x.fsf@DESKTOP-5N7EMDA> User-Agent: Gnus/5.13 (Gnus v5.13) 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=ascii "Zhijian Li (Fujitsu)" writes: > Hi, > > > On 25/06/2025 10:13, Li Zhijian wrote: >> V2: >> Fix compiling error # Reported by LKP >> >> As Ying suggested, we need to assess whether this change causes regression. >> However, considering the stringent conditions this patch involves, >> properly evaluating it may be challenging, as the outcomes depend on your >> perspective. Much like in a zero-sum game, if someone benefits, another >> might lose. >> >> If there are subsequent results, I will update them here. > > I ran memhog + pmbench to evaluate the impact of the patch(3 runs [1] for each kernel). > > The results show an approximate 4% performance increase in pmbench after applying this patch. > > Average pmbench-access max-promotion-rate > Before: 7956805 pages/sec 168301 pages/sec > After: 8313666 pages/sec (+4.4%) 207149 pages/sec It's hard for me to understand why performance increases because of higher promotion rate, while the expected behavior is more promotion rate limiting. > The detailed logs are available at [2]. > > [1] https://github.com/zhijianli88/misc/blob/main/20250627/promotion-evaluation/reproduce.sh > [2] https://github.com/zhijianli88/misc/tree/main/20250627/promotion-evaluation [snip] --- Best Regards, Huang, Ying