From nobody Sat Nov 23 23:41:01 2024 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.2]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E7239D2FA; Sun, 10 Nov 2024 04:53:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.2 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731214412; cv=none; b=VBZpcRV+3tdqBSvIMcV5hSr6PYVWBpyTgEzDQD+tOr9r/rRQEFRdEbmaKy0jLq+BmeI0csXiPZk+aRyAV9yxhvMEFZdV9Qmm0nNlvGkh0G2t4OZXlYp9r8AYTsrz7zePraj1zMfGPFF/lo2+88CAtHeNBu1bKbC4vyihcwAlqCg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731214412; c=relaxed/simple; bh=Acy5eGAhWgxkyGU/f5UmK0PsdRN6Scg4QxeIp1wqEfs=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=CtEt1ERKfT6+8wl+bgwBXU8I2LQa1zlMt1FklZnysu4s5PTt4NawOy80EVROjN3lZ0rdY9/MzhQvaPIl75nruF6+VhtTm4x4PYmOLBkYKRU9IDA8zZHjp6wJVMRfpnZceAGlB8+AgxV1EFNGFBen9SijYycFUlOJHVPiWvyeiZ0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=YtY6tIkQ; arc=none smtp.client-ip=220.197.31.2 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="YtY6tIkQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=k0aNs uiJeOW3JSrOJtiMNVEl/LdLoETA7BfyQ4D8UCo=; b=YtY6tIkQERLmtmQib+6G+ fkhqIqzQL3pBtH0KBTAAyfATvdvlZDiO2JnfJ5xKZZ6/63hCfNSzGEn1WqyqH/WT Z+chtWP3HpYKBGYAMD5EaSIliqOdSnWgMLgEd999w3tyk+QggFgn6bc0qCoXKLXr 5mVaRwHLP+phSVeipvwXoY= Received: from localhost.localdomain (unknown [111.35.191.191]) by gzsmtp3 (Coremail) with SMTP id PigvCgBnsJgGPDBnwu2xBg--.36552S4; Sun, 10 Nov 2024 12:52:37 +0800 (CST) From: David Wang <00107082@163.com> To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, David Wang <00107082@163.com> Subject: [PATCH] net/core/net-procfs: use seq_put_decimal_ull_width() for decimal values in /proc/net/dev Date: Sun, 10 Nov 2024 12:52:21 +0800 Message-Id: <20241110045221.4959-1-00107082@163.com> X-Mailer: git-send-email 2.39.2 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: PigvCgBnsJgGPDBnwu2xBg--.36552S4 X-Coremail-Antispam: 1Uf129KBjvJXoWxXr15Jr45Cry3Xr1Dtw4Utwb_yoWrXr1rpF y3KasIqr48Xr98tF1DJrZ2q34FqFySvF47W3ZrG3yfG3W5Xr95Jr1FgrW2kF1UG3yDAw45 t3srWFyYy3yjgr7anT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pE1vVZUUUUU= X-CM-SenderInfo: qqqrilqqysqiywtou0bp/1tbiMweTqmcwLjy4QQAAsx Content-Type: text/plain; charset="utf-8" seq_printf() is costy, when reading /proc/net/dev, profiling indicates about 13% samples of seq_printf(): dev_seq_show(98.350% 428046/435229) dev_seq_printf_stats(99.777% 427092/428046) dev_get_stats(86.121% 367814/427092) rtl8169_get_stats64(98.519% 362365/367814) dev_fetch_sw_netstats(0.554% 2038/367814) loopback_get_stats64(0.250% 919/367814) dev_get_tstats64(0.077% 284/367814) netdev_stats_to_stats64(0.051% 189/367814) _find_next_bit(0.029% 106/367814) seq_printf(13.719% 58594/427092) And on a system with one wireless interface, timing for 1 million rounds of stress reading /proc/net/dev: real 0m51.828s user 0m0.225s sys 0m51.671s On average, reading /proc/net/dev takes ~0.051ms With this patch, extra costs parsing format string by seq_printf() can be optimized out, and the timing for 1 million rounds of read is: real 0m49.127s user 0m0.295s sys 0m48.552s On average, ~0.048ms reading /proc/net/dev, a ~6% improvement. Even though dev_get_stats() takes up the majority of the reading process, the improvement is still significant; And the improvement may vary with the physical interface on the system. Signed-off-by: David Wang <00107082@163.com> --- net/core/net-procfs.c | 37 ++++++++++++++++++++----------------- 1 file changed, 20 insertions(+), 17 deletions(-) diff --git a/net/core/net-procfs.c b/net/core/net-procfs.c index fa6d3969734a..a0d6c5b32b58 100644 --- a/net/core/net-procfs.c +++ b/net/core/net-procfs.c @@ -46,23 +46,26 @@ static void dev_seq_printf_stats(struct seq_file *seq, = struct net_device *dev) struct rtnl_link_stats64 temp; const struct rtnl_link_stats64 *stats =3D dev_get_stats(dev, &temp); =20 - seq_printf(seq, "%6s: %7llu %7llu %4llu %4llu %4llu %5llu %10llu %9llu " - "%8llu %7llu %4llu %4llu %4llu %5llu %7llu %10llu\n", - dev->name, stats->rx_bytes, stats->rx_packets, - stats->rx_errors, - stats->rx_dropped + stats->rx_missed_errors, - stats->rx_fifo_errors, - stats->rx_length_errors + stats->rx_over_errors + - stats->rx_crc_errors + stats->rx_frame_errors, - stats->rx_compressed, stats->multicast, - stats->tx_bytes, stats->tx_packets, - stats->tx_errors, stats->tx_dropped, - stats->tx_fifo_errors, stats->collisions, - stats->tx_carrier_errors + - stats->tx_aborted_errors + - stats->tx_window_errors + - stats->tx_heartbeat_errors, - stats->tx_compressed); + seq_printf(seq, "%6s:", dev->name); + seq_put_decimal_ull_width(seq, " ", stats->rx_bytes, 7); + seq_put_decimal_ull_width(seq, " ", stats->rx_packets, 7); + seq_put_decimal_ull_width(seq, " ", stats->rx_errors, 4); + seq_put_decimal_ull_width(seq, " ", stats->rx_dropped + stats->rx_missed_= errors, 4); + seq_put_decimal_ull_width(seq, " ", stats->rx_fifo_errors, 4); + seq_put_decimal_ull_width(seq, " ", stats->rx_length_errors + stats->rx_o= ver_errors + + stats->rx_crc_errors + stats->rx_frame_errors, 5); + seq_put_decimal_ull_width(seq, " ", stats->rx_compressed, 10); + seq_put_decimal_ull_width(seq, " ", stats->multicast, 9); + seq_put_decimal_ull_width(seq, " ", stats->tx_bytes, 8); + seq_put_decimal_ull_width(seq, " ", stats->tx_packets, 7); + seq_put_decimal_ull_width(seq, " ", stats->tx_errors, 4); + seq_put_decimal_ull_width(seq, " ", stats->tx_dropped, 4); + seq_put_decimal_ull_width(seq, " ", stats->tx_fifo_errors, 4); + seq_put_decimal_ull_width(seq, " ", stats->collisions, 5); + seq_put_decimal_ull_width(seq, " ", stats->tx_carrier_errors + stats->tx_= aborted_errors + + stats->tx_window_errors + stats->tx_heartbeat_errors, 7); + seq_put_decimal_ull_width(seq, " ", stats->tx_compressed, 10); + seq_putc(seq, '\n'); } =20 /* --=20 2.39.2