From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B0EE21F7088; Tue, 3 Dec 2024 14:56:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733237779; cv=none; b=DlXkYdiDix94I0lrj8RDn8vhQVvNcZ6OMxDN48AqQLplHRAvhJaT6xtepFDSeNud+cCFMpvGHs+qxyKBNLma4fPju22UIhvRK1ZjRYoW6+uqJ8Vh7l5kxx22OQSdumMdQJhBmOsfhDbwdV6ufn6VUwAIs+pcn7vDzFk2IbEYE9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733237779; c=relaxed/simple; bh=8quSxeUOsc4kzDT2pRYv1Wy/9oLnsuhuNnj2XVWmg30=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=RekcTrNgmx1qH6LTeeeWvUVyUFYXHVkWr4ZdMVNaNTE4jz9OW6BzG/YAA6z5H0QJdZ6E9C/vLJpCi2+Lm10XOIysV3ANY3ur28vXRS9ECg8RU84wwGBdx4wW2R7nD+2NOfyXcDuvFOpiJO+TeNhkh9X1Yu64RfjWRosTnusUD98= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KGR3vAEp; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KGR3vAEp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BAE1CC4CED6; Tue, 3 Dec 2024 14:56:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1733237779; bh=8quSxeUOsc4kzDT2pRYv1Wy/9oLnsuhuNnj2XVWmg30=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KGR3vAEpU5FHO3dzWiKRK1tqwuW4r9/TtGIT+6gtFcPV4hJCZKlRefgjgWCwjZH2H BZ6sgEuSvTCPIC9aoBunngsAq1SWVQ7unEuafyqS4t4q3sivQ5nVAzR6Jf9ESvTUNd gTqhepHKwNN/Nv4KU8KCLxZS71oDEAm/YNh6+FNY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, David Wang <00107082@163.com>, Linus Torvalds , Sasha Levin Subject: [PATCH 6.11 036/817] proc/softirqs: replace seq_printf with seq_put_decimal_ull_width Date: Tue, 3 Dec 2024 15:33:28 +0100 Message-ID: <20241203143957.060832110@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20241203143955.605130076@linuxfoundation.org> References: <20241203143955.605130076@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.11-stable review patch. If anyone has any objections, please let me know. ------------------ From: David Wang <00107082@163.com> [ Upstream commit 84b9749a3a704dcc824a88aa8267247c801d51e4 ] seq_printf is costy, on a system with n CPUs, reading /proc/softirqs would yield 10*n decimal values, and the extra cost parsing format string grows linearly with number of cpus. Replace seq_printf with seq_put_decimal_ull_width have significant performance improvement. On an 8CPUs system, reading /proc/softirqs show ~40% performance gain with this patch. Signed-off-by: David Wang <00107082@163.com> Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/proc/softirqs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/softirqs.c b/fs/proc/softirqs.c index f4616083faef3..04bb29721419b 100644 --- a/fs/proc/softirqs.c +++ b/fs/proc/softirqs.c @@ -20,7 +20,7 @@ static int show_softirqs(struct seq_file *p, void *v) for (i = 0; i < NR_SOFTIRQS; i++) { seq_printf(p, "%12s:", softirq_to_name[i]); for_each_possible_cpu(j) - seq_printf(p, " %10u", kstat_softirqs_cpu(i, j)); + seq_put_decimal_ull_width(p, " ", kstat_softirqs_cpu(i, j), 10); seq_putc(p, '\n'); } return 0; -- 2.43.0