Re: why is system getting stuck ...

>>> Recently, I have begun to have recurring issues
>>> with my Linux Mint 18.1 system seeming to get "stuck"
>>> and I can't figure out why. I leave my system running
>>> 24/7 and have rarely had a reason or need to shut down.
>>> It has now been running (mostly fine) for 10 days.
>>> The recent problems have happened with both the chrome
>>> browser and the firefox browser (open at separate times).
>>> Various symptoms include the screen seeming to "freeze"
>>> sometimes with the cursor pointer disappearing, sometimes
>>> it changes to an "I" instead of an arrow pointer and is
>>> either unmovable on the screen or sometimes it can be
>>> moved, but at a drunken snail's pace.
>>> Sometimes the screen goes blank and if I walk away and
>>> come back after several minutes, the screen is restored
>>> and the cursor can be moved again.
>>> I have uploaded a screen shot and two text files as
>>> examples, including top.txt ... ps-ef.txt ... and a couple
>>> of screen shots. Can someone tell me what processes ps-ef
>>> show that should be or could be killed?
>>> Why does top-txt show two instances of chrome running ??
>>> Why does top whoc 4 users when 'who' shows only 3?
>>> And why are there 3 users when I am the only user?
>>> http://www.upquick.com/temp/freeze.jpg
>>> http://www.upquick.com/temp/top-txt
>>> http://www.upquick.com/temp/ps-ef.txt
>>> t420: who
>>> joe      tty8         2018-02-28 14:39 (:0)
>>> joe      pts/2        2018-05-22 15:43 (:0)
>>> joe      pts/5        2018-02-28 14:40 (:0)
>>> top - 15:47:20 up 170 days,  5:29,  4 users,  load average: 0.22, 1.01,
>>> 10.65
>>> Tasks: 245 total,   2 running, 235 sleeping,   0 stopped,   8 zombie
>>> %Cpu(s):  5.0 us,  1.3 sy,  0.0 ni, 93.6 id,  0.1 wa,  0.0 hi,  0.0 si,
>>> 0.0 st
>>> KiB Mem:   8056428 total,  3870692 used,  4185736 free,   134676 buffers
>>> KiB Swap:  1951740 total,  1769720 used,   182020 free.  1161048 cached
>>> Mem
>>>   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+
>>> COMMAND
>>> 10665 joe       20   0 3832944 239268  63624 S  11.9  3.0   6649:51
>>> plasma-desk+
>>> 15697 joe       20   0  511896  50588  35968 S   5.3  0.6   0:05.17
>>> konsole
>>> 10241 root      20   0  419892 148588  99172 S   4.0  1.8   1567:26 Xorg
>>> 10659 joe       20   0 3247440  90844  18280 S   0.7  1.1 642:54.34 kwin
>>> 18274 joe       20   0 1841712 181908     16 S   0.7  2.3  50:10.02
>>> chrome ***** (1)
>>>     8 root      20   0       0      0      0 S   0.3  0.0  75:00.93
>>> rcuos/0
>>>   487 root     -51   0       0      0      0 S   0.3  0.0 464:58.53
>>> irq/44-iwlw+
>>>  1174 root      20   0    4388    224    100 S   0.3  0.0 112:21.59 acpid
>>> 14574 root      20   0       0      0      0 S   0.3  0.0   0:00.42
>>> kworker/u16+
>>> 15757 joe       20   0   24964   3168   2568 R   0.3  0.0   0:00.81 top
>>> 31023 joe       20   0 1752576  36352      0 S   0.3  0.5 149:49.69
>>> chrome ***** (2)
>>>     1 root      20   0   37500   2096      0 S   0.0  0.0   0:14.22 init
>>>     2 root      20   0       0      0      0 S   0.0  0.0   0:03.73
>>> kthreadd
>>>     3 root      20   0       0      0      0 S   0.0  0.0  10:32.60
>>> ksoftirqd/0
>>>     5 root       0 -20       0      0      0 S   0.0  0.0   0:00.00
>>> kworker/0:0H
>>>     7 root      20   0       0      0      0 S   0.0  0.0 136:59.67
>>> rcu_sched
>>>     9 root      20   0       0      0      0 S   0.0  0.0  23:30.73
>>> rcuos/1
>>>    10 root      20   0       0      0      0 S   0.0  0.0  44:27.97
>>> rcuos/2
>>>    11 root      20   0       0      0      0 S   0.0  0.0  25:53.54
>>> rcuos/3
>>>    12 root      20   0       0      0      0 S   0.0  0.0   0:00.01
>>> rcuos/4
>>>    13 root      20   0       0      0      0 S   0.0  0.0   0:00.01
>>> rcuos/5
>>>    14 root      20   0       0      0      0 S   0.0  0.0   0:00.01
>>> rcuos/6
>>>    15 root      20   0       0      0      0 S   0.0  0.0   0:00.01
>>> rcuos/7
>>>    16 root      20   0       0      0      0 S   0.0  0.0   0:00.00
>>> rcu_bh