Painfully slow compilation (read: "make buildworld buildkernel") on not-so-weak system

[Lev Serebryakov]

Hello Lev,

Saturday, December 8, 2018, 2:13:03 PM, you wrote:


>  Another strange thing I noticed: when system is in such state, "top -SH"
> shows that sometimes very low-profile processes, like clock software
> interrupt (!) could consume large amount of CPU for short periods time. When
> system is idle there never will be "intr{swi4: clock (0)}" consuming 55% CPU
> for one "frame" or sshd, or screen itself.
 Like this. This system doesn't have any significant network traffic now —
only one ssh connection, which is used as console. And 62.3% for network
card. WTF?!

  PID USERNAME    PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
20128 root        101    0   104M    74M CPU1     1   0:31 100.00% cc
    0 root        -76    -      0  4608K -        2  53:25  62.23% kernel{if_config_tqg_0}
   11 root        -60    -      0   240K WAIT     0  25:45  24.89% intr{swi4: clock (0)}
    9 root         -8    -      0   160K tx->tx   0   7:38  24.88% zfskern{txg_thread_enter}
  995 root         24    0    17M  7676K select   1   2:20  12.44% sendmail
13791 root         24    0    24M    15M select   0   0:04  12.44% make




-- 
Best regards,
 Lev                            mailto:lev at FreeBSD.org