【发布时间】：2022-08-24 15:57:59
【问题描述】：
我从从 PTP 节点上的 ptp4l 命令获得以下输出。当我终止它时，会打印出一些全局统计信息，但我无法解释这些值，因为我没有发现与上述输出中的值有任何明显的对应关系。准确地说，我知道offset、min、max 字段一般应该指的是什么，但是：
- 为什么会有对每个字段的值而不是单个值
-
dev实际上是什么？如果它是“某物”的标准差，那么拥有min和max子字段有什么意义？ - 这些值对应该如何计算或与上述记录相关联？
- 你能解释一下
drift的含义吗？# ptp4l -p /dev/ptp0 -i eth0 -l 6 -m -s -2
ptp4l[156535.175]: selected /dev/ptp0 as PTP clock ptp4l[156535.179]: port 1: INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[156535.181]: port 0: INITIALIZING to LISTENING on INIT_COMPLETE ptp4l[156535.183]: version=2 ports=2 ptp4l[156535.184]: access_delay=164000 ptp4l[156535.185]: UTC offset: 37 ptp4l[156535.187]: port 1: link up ptp4l[156536.340]: port 1: new foreign master 0010a1.fffe.9477ff-1 ptp4l[156540.354]: selected best master clock 0010a1.fffe.9477ff ptp4l[156540.355]: port 1: LISTENING to UNCALIBRATED on RS_SLAVE ptp4l[156541.044]: master offset 3199658 s0 freq -3906 path delay 0 ptp4l[156542.055]: master offset 3199829 s3 freq -3737 path delay 0 ptp4l[156543.066]: master offset 3199792 s1 freq -3737 path delay 38 ptp4l[156544.077]: master offset -8 s2 freq -3739 path delay 38 ptp4l[156544.078]: port 1: UNCALIBRATED to SLAVE on MASTER_CLOCK_SELECTED ptp4l[156545.088]: master offset -25 s2 freq -3752 path delay 40 ptp4l[156546.099]: master offset -34 s2 freq -3759 path delay 40 ptp4l[156547.110]: master offset -43 s2 freq -3768 path delay 41 ptp4l[156548.111]: master offset -17 s2 freq -3757 path delay 41 ptp4l[156549.122]: master offset -19 s2 freq -3759 path delay 39 ptp4l[156550.133]: master offset -12 s2 freq -3757 path delay 39 ptp4l[156551.144]: master offset -7 s2 freq -3755 path delay 40 ptp4l[156552.155]: master offset -20 s2 freq -3764 path delay 40 ptp4l[156553.166]: master offset -9 s2 freq -3759 path delay 40 ptp4l[156554.177]: master offset -11 s2 freq -3761 path delay 40 ^C1=19:0 0:0 ptp4l[156554.674]: ptp4l[156554.674]: offset: ptp4l[156554.674]: dev = 4.716450, -12.571429 ptp4l[156554.674]: min = 4.716450, 12.571429; max = 4.966555, 14.000000 ptp4l[156554.674]: dev: ptp4l[156554.675]: dev = 1.903343, 3.305985 ptp4l[156554.675]: min = 1.903343, 2.691777; max = 1.959507, 3.305985 ptp4l[156554.675]: drift: ptp4l[156554.675]: dev = 2.623987, -3758.795853 ptp4l[156554.675]: min = 2.623987, 3758.372996; max = 2.934894, 3758.795853 ptp4l[156554.676]: avg: 12