From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 B7E923BED78; Sat, 12 Sep 2026 20:08:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789243704; cv=none; b=JI8btvEMmMXDFXMmOEshf4oErIljS9FKnO6X5mmfRwXNaUeIVZdxv7Y1cAQbxAGG4adlhVEFjYnVJYMszpb/3ceQYc8J7fdMIwiK8yREM4Y4xd69BUGCEyj8lrFMa1AVY+KI2UXOM+5Xl7HTJJF2eeYxkCpivf6McpgScxFqYGk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789243704; c=relaxed/simple; bh=lnN8yBlO5SqLcW4TZiSS6k10RAiAzY1fYevG0oy3Dso=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jzNvJ1f/Ack+zZvO85MuolDf6pMyIwIBwtna0ZHy+UwTdJcsmtL0uwGwloUvxLey5qVrVBlEs6e8gbe6/HjOiGCFSMoyxrxM2H63Sly3CFwzJjBDGyi0Wxh9BRCqEfrMQCT9dXKmbzqTtWR+BRfKrOBXb3bjBfdmq6EPi+CPHgs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ojJaqsSm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ojJaqsSm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6456E1F00898; Sat, 12 Sep 2026 20:08:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789243703; bh=jlghyvZVNP8/XL0yY4KLFntdcCcvr5Jln0kHwD1ylXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ojJaqsSm35JPnh3SwZ7uQ9wBPo68CoQtaBz99FqPU3hETd9okd3Wa/EAhAh9CE8X8 vUvqGTGcOKoqMVisbqQ+8Y2lBEdiGgkO2gIQ1eqXEg4qj579gOaCixglPUJkZfBPL2 5UXe5PapAxYJWbQHwx7XxFAYOT+li0mw9Y4eBsw/1rVXBnWO4M7UeVa2jnr46TRqHz k0a5oBALMN93AWKBId4DIr0qpQWdof7CmQu73mWCL1M/7AZFTeyi+H958MVaDDhgDu fJqcThaaLnhOGY2NZxi13bbsBIAWibTZ2cflakSq7EPPjltFY6a/bWOS+31c56Gl8D H0LbzKxr3+OnA== From: SJ Park To: Cc: SJ Park , Andrew Morton , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH 3/9] mm/damon/core: use mult_frac() in damon_feed_loop_next_input() Date: Sat, 12 Sep 2026 13:08:04 -0700 Message-ID: <20260912200814.145612-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260912200814.145612-1-sj@kernel.org> References: <20260912200814.145612-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 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 61bb25674cd23..cf10f6d725c19 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -2921,11 +2921,7 @@ 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); -- 2.47.3