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 EC5BB5908C0; Thu, 17 Sep 2026 14:22:19 +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=1789654941; cv=none; b=F9bXfHSC7PNLxBHEj/AYOhEuA4JzzAoFWsTA31LJC3gi0hVUCeJ9kmzitgi/aZW7x+MRMHV65zumpwU36EDar8tb7rg9apfvtqgcpaGb4FpzPcTDBUAnPYeOOl8oYt23SbmaclWq4tlWRhjKxzcgEP/aQN7G+hz6LOKWK+IdxQg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789654941; c=relaxed/simple; bh=VaDYdo4YPv5i47nFcp1UcmGveOFil6j1xbLCRiCXscg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=mNQ64N7wH4Wl9+m7S1pMxvBhKv3//uIdCtXFjklLOk8t6/H+1Bl/nPA+67Ht5P1Xt33RSK8MaYtcMClXYJTRcon5+ZR5J8/rKKadaL8qm0D4Y5EoSgqSrsY9EXk2Fd2QeZl2haHow3lY+Wo9nzZaSsPnfRHoKWwCllSti/YiJzI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=h5ExFZPJ; 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="h5ExFZPJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 698B91F0089A; Thu, 17 Sep 2026 14:22:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789654939; bh=G4i9YVdly64+a304TiCv8nwcHkLss6xqStxGSND5/ec=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=h5ExFZPJQqiTePp/WDl73sof3pqfsr/hdjFIOJ3lWzZVKGNrtN2V8/Ojg3ODcNRq7 1paKZ44w7an5o/r95vLVQv0bk4qiUZukq79QAXR2ZqdBkofCE0xLAl9TJrzFwtvJcE ijDZn/rSTZtXH+MW1Bw8sNSFaZU7VsiiLNetPjm+IJqzE6WxgjoKHkrTLSE/rm3pXW xZNQB4GzoKlISfZh6wVJLLic5/78/BKiecMDKc6zrvcbYIsEA/EYPmWYxkhH+jgMFs +y2OjyLKNf7NF9FLh586Wz6pPCalP5v6BapcLU3zT4nHbgz4f1xG0lXfaKpNmzQuSp 2Z7RIfsHMLVHQ== From: SJ Park To: Andrew Morton Cc: SJ Park , damon@lists.linux.dev, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH 03/10] mm/damon/core: use mult_frac() in damon_feed_loop_next_input() Date: Thu, 17 Sep 2026 07:22:01 -0700 Message-ID: <20260917142210.90829-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260917142210.90829-1-sj@kernel.org> References: <20260917142210.90829-1-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 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); -- 2.47.3