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 2CB6B2280A9; Tue, 12 Nov 2024 10:37:41 +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=1731407862; cv=none; b=OTEVYwXYcLomOljKclVEUl7tpk+izpsQtzsk1DaXK+9Hw8N5DOpPPTAWpJWKSB06ueWYeqPzhZHIiwj7oWfRv99cY/TM1gXJB8F8unjVjtCM9EDBtjEi7wybN9br/4eZqmQ/PDF36EuiQjGqCyT5bNfEoGDfkutyfQOp+2lULrE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731407862; c=relaxed/simple; bh=tSHtvglTHqGCMeJEkIb1FMtoexRMYub3jo+WZxZEg8A=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Bspvg6kCNES9TrO3mDQVFuIDGRcKwfcp5X61mZgGPOWY+3Rw/mVJrmNSxuYxkOPftwkGHIRn9LzNTpHYudIWqnqbaBZIg13vhB6kYn7XLZNEHj9saqGl/kIbnQzlkTKfzW92FOvruP7Qy/cgpRPfq5qKrl0VmZYhHX2qetjoVR0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=DAFIR4Zj; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="DAFIR4Zj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 08A08C4CED7; Tue, 12 Nov 2024 10:37:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731407861; bh=tSHtvglTHqGCMeJEkIb1FMtoexRMYub3jo+WZxZEg8A=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=DAFIR4ZjMdgAfZ5xzqzJUBnUMcwQ9nV9cRF66YaBw+aGvQicBinTGJ+F60Ak9wwfP vBbNHpoDZjiSkrB+HFz0kEwQT2r29QeCyP22AiT+rZNIEmYLgxE4nT2AwVEd8jkspo q0OiD3TB+v0Rsi3cgr4NqOzw7MA59ewAjlAVHe7VE8+pD1h4RAXbpycp9psqAmJhlw OMZ/2lQ7EyeiNM/Hq8IdM446Je/AURoxxdiETTaLKpwj+bMSpLqh/ELvMPb5CdIrQJ K9ndqLYppuSLXim2Sz7BkqgXajCTO2Ls+ucgYGdMNAr2OTUSnNQHSZ5ywZsgfsMzo/ xqfGA0dC45oog== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: David Wang <00107082@163.com>, Linus Torvalds , Sasha Levin , linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 12/12] proc/softirqs: replace seq_printf with seq_put_decimal_ull_width Date: Tue, 12 Nov 2024 05:37:14 -0500 Message-ID: <20241112103718.1653723-12-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20241112103718.1653723-1-sashal@kernel.org> References: <20241112103718.1653723-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 6.1.116 Content-Transfer-Encoding: 8bit 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