From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (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 1AAE958E2D6 for ; Thu, 17 Sep 2026 14:44:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789656280; cv=none; b=N64YVKG8P1eu3QwX6JUAFuU/kfmzDwQjl4nGSmqCeOX93jSjwhu2GcPJDVEoIb3F64SGnfGVA03BquqdiRZoxKoRPVrK68Rip352xzMfZRU52LhScnsaUvtF5UTCrVEvrzvMw2dLuRTlsSY3ED8RLTcpZejekr+A/9pwcpfDG3k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789656280; c=relaxed/simple; bh=L0jOHxxKNdjxHupbT6eiicRsacK8w3vHEPvNN5WP+8E=; h=Message-ID:Date:MIME-Version:Subject:To:CC:References:From: In-Reply-To:Content-Type; b=CIEUCIJmLxHV5iKUK7Sw1U4UvlRsB7gTSuiiQsLJZakIf4t2PbG9trnhMzXqu0VXhVHg/iqGcs41e98GDfR4DefiB1TcdGyu7Bj13+KtCHXzr35UiuwsWRh9g65fq7BoW5ZTUkP94Nx2UdS/+KNMi0BuVEc2w/RbJ6ExBjS0it8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei-partners.com; spf=pass smtp.mailfrom=huawei-partners.com; dkim=pass (1024-bit key) header.d=huawei-partners.com header.i=@huawei-partners.com header.b=RScLDk2o; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei-partners.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei-partners.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei-partners.com header.i=@huawei-partners.com header.b="RScLDk2o" dkim-signature: v=1; a=rsa-sha256; d=huawei-partners.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=r6sH0YRnOsx9ADT5cVOZaWbkhNPDhNeBUllgAggui2w=; b=RScLDk2onGX0+mDgTvLhod536XLzUT92fXxoV9S/M1qsKC+Iwo09H3jDk2nl0+PkGiJlCffn1 ubuaGkO1Dfhlvzq6oDpmHEdXyOBEhPxdXt+1Tx7WDijYrh0Oj/kHhYwRpuVRz1hV1ima/1u60um dNvKth28CBCEejisxJPMl3o= Received: from mail.maildlp.com (unknown [172.18.224.150]) by frasgout.his.huawei.com (SkyGuard) with ESMTPS id 4hlz6B6ZxWzHnHJt; Thu, 17 Sep 2026 22:44:02 +0800 (CST) Received: from mscpeml500003.china.huawei.com (unknown [7.188.49.51]) by mail.maildlp.com (Postfix) with ESMTPS id 91CFC40571; Thu, 17 Sep 2026 22:44:19 +0800 (CST) Received: from [10.123.123.154] (10.123.123.154) by mscpeml500003.china.huawei.com (7.188.49.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.2562.46; Thu, 17 Sep 2026 17:44:19 +0300 Message-ID: <643b7cce-cfb4-461b-9e4f-89439ee7eee3@huawei-partners.com> Date: Thu, 17 Sep 2026 17:44:18 +0300 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: [PATCH 03/10] mm/damon/core: use mult_frac() in damon_feed_loop_next_input() To: SJ Park , Andrew Morton CC: , , References: <20260917142210.90829-1-sj@kernel.org> <20260917142210.90829-4-sj@kernel.org> Content-Language: en-US From: Gutierrez Asier In-Reply-To: <20260917142210.90829-4-sj@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: mscpeml500004.china.huawei.com (7.188.26.250) To mscpeml500003.china.huawei.com (7.188.49.51) On 9/17/2026 5:22 PM, SJ Park wrote: > damon_feed_loop_next_input() does its best effort overflow protection. > score_goal_diff is always smaller than goal (10,000). Hence the > calculation can be replaced to use mult_frac() without concerning the > overflow. Use mult_frac(). > > Signed-off-by: SJ Park > --- > mm/damon/core.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/mm/damon/core.c b/mm/damon/core.c > index de46072dc1a2f..bc41ac7ecca43 100644 > --- a/mm/damon/core.c > +++ b/mm/damon/core.c > @@ -2927,11 +2927,7 @@ static unsigned long damon_feed_loop_next_input(unsigned long last_input, > return min_input; > > score_goal_diff = abs_diff(score, goal); > - > - if (last_input < ULONG_MAX / score_goal_diff) > - compensation = last_input * score_goal_diff / goal; > - else > - compensation = last_input / goal * score_goal_diff; > + compensation = mult_frac(last_input, score_goal_diff, goal); > > if (over_achieving) > return max(last_input - compensation, min_input); LGTM Reviewed-by: Asier Gutierrez -- Asier Gutierrez Huawei