Process Linux线程优先级值

我是Linux新手。我被线程优先级搞糊涂了

top PR和ps PRI的区别是什么，为什么它们是不同的

  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
    1 root      20   0  2804 1664 1220 S  0.0  0.3   0:01.30 init
    2 root      20   0     0    0    0 S  0.0  0.0   0:00.00 kthreadd
    3 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 migration/0
    4 root      20   0     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
    5 root      RT   0     0    0    0 S  0.0  0.0   0:00.00 watchdog/0
    6 root      20   0     0    0    0 S  0.0  0.0   0:00.02 events/0


c@c-desktop:~$ ps -el
F S   UID   PID  PPID  C PRI  NI ADDR SZ WCHAN  TTY          TIME CMD
4 S     0     1     0  0  80   0 -   701 poll_s ?        00:00:01 init
1 S     0     2     0  0  80   0 -     0 kthrea ?        00:00:00 kthreadd
1 S     0     3     2  0 -40   - -     0 migrat ?        00:00:00 migration/0
1 S     0     4     2  0  80   0 -     0 ksofti ?        00:00:00 ksoftirqd/0
5 S     0     5     2  0 -40   - -     0 watchd ?        00:00:00 watchdog/0
1 S     0     6     2  0  80   0 -     0 worker ?        00:00:00 events/0

我在源文件procps/output.c中找到了答案

In linux procps, the column labeled "PRI" in ps -l is -o opri

// # ps -C19,_20 -o pri,opri,intpri,priority,ni,pcpu,pid,comm
// PRI PRI PRI PRI  NI %CPU  PID COMMAND
//   0  99  99  39  19 10.6 8686 19
//  34  65  65   5 -20 94.7 8687 _20

// "priority"         (was -20..20, now -100..39)
static int pr_priority(char *restrict const outbuf, const proc_t *restrict const pp){    /* -20..20 */
    return snprintf(outbuf, COLWID, "%ld", pp->priority);
}
// "intpri" and "opri" (was 39..79, now  -40..99)
static int pr_opri(char *restrict const outbuf, const proc_t *restrict const pp){        /* 39..79 */
    return snprintf(outbuf, COLWID, "%ld", 60 + pp->priority);
}
// "pri_foo"   --  match up w/ nice values of sleeping processes (-120..19)
// "pri_bar"   --  makes RT pri show as negative       (-99..40)
// "pri_baz"   --  the kernel's ->prio value, as of Linux 2.6.8     (1..140)
// "pri"               (was 20..60, now    0..139)
// "pri_api"   --  match up w/ RT API    (-40..99)

排名靠前的PR等于“优先级”

---

ps中的PRI等于“opri”

我从procps源代码中找到了答案。thx.@Ali你能在这里更新答案吗？