我想以编程方式[在C中]为Linux中给定进程ID计算CPU使用率%。
如何获得给定进程的实时CPU使用率%?
为了进一步说明:
您需要从中解析出数据/proc/<PID>/stat。这些是前几个字段(来自Documentation/filesystems/proc.txt内核源代码):
/proc/<PID>/stat
Documentation/filesystems/proc.txt
Table 1-3: Contents of the stat files (as of 2.6.22-rc3) .............................................................................. Field Content pid process id tcomm filename of the executable state state (R is running, S is sleeping, D is sleeping in an uninterruptible wait, Z is zombie, T is traced or stopped) ppid process id of the parent process pgrp pgrp of the process sid session id tty_nr tty the process uses tty_pgrp pgrp of the tty flags task flags min_flt number of minor faults cmin_flt number of minor faults with child's maj_flt number of major faults cmaj_flt number of major faults with child's utime user mode jiffies stime kernel mode jiffies cutime user mode jiffies with child's cstime kernel mode jiffies with child's
您可能在utime和/或之后stime。您还需要从中读取cpu行/proc/stat,如下所示:
utime
stime
cpu
/proc/stat
cpu 192369 7119 480152 122044337 14142 9937 26747 0 0
这将告诉您已在各种类别中以累计量为单位使用的累计CPU时间。您需要对这条线上的值求和才能得到time_total度量。
time_total
同时读取utime并stime进行过程中,你有兴趣,并阅读time_total来自/proc/stat。然后睡一秒钟左右,然后再次阅读它们。现在,您可以使用以下命令计算采样时间内该进程的CPU使用率:
user_util = 100 * (utime_after - utime_before) / (time_total_after - time_total_before); sys_util = 100 * (stime_after - stime_before) / (time_total_after - time_total_before);
合理?