Re: head -r3418363: top -opid process list order is rather odd (top -Saopid example shown)

From: Mark Millard <marklmi_at_yahoo.com>
Date: Mon, 24 Dec 2018 15:38:27 -0800
On 2018-Dec-24, at 13:49, Yuri Pankov <yuripv at yuripv.net> wrote:

> Mark Millard wrote:
>> From my from=source head -r3418363 context, top with -opid does not
>> seem to sort in a coherent order, not time of process creation order
>> (either direction) and not in just-PID numeric order (either
>> direction). For example:
>> 
>>  PID USERNAME    THR PRI NICE   SIZE    RES STATE    C   TIME    WCPU COMMAND
>>    0 root         24 -16    -      0   368K swapin   1   0:00   0.00% [kernel]
>>   16 root          1 -16    -      0    16K -        3   0:00   0.00% [soaiod2]
>>  752 root          1  20    0    18M    18M select   1   0:07   0.01% /usr/sbin/ntpd -p /var/db/ntp/ntpd.pid -c /etc/ntp.conf -g
>>  800 root          1  20    0    11M   908K nanslp   1   0:01   0.00% /usr/sbin/cron -s
>>    1 root          1  20    0  9900K   132K wait     3   0:00   0.00% [init]
>>   17 root          1 -16    -      0    16K -        0   0:00   0.00% [soaiod3]
>>    2 root          1 -16    -      0    16K crypto   0   0:00   0.00% [crypto]
>>   18 root          1 -16    -      0    16K -        0   0:00   0.00% [soaiod4]
>>  850 root          1  20    0    13M  2756K wait     3   0:00   0.00% login [pam] (login)
>>    3 root          1 -16    -      0    16K crypto   0   0:00   0.00% [crypto returns 0]
>>   19 root          1 -16    -      0    16K mmcsd    0   0:25   0.00% [mmcsd0: mmc/sd card]
>>  643 root          1  20    0    11M  1124K select   2   0:01   0.00% /usr/sbin/syslogd -s
>>    4 root          1 -16    -      0    16K crypto   0   0:00   0.00% [crypto returns 1]
>>   20 root          1 -16    -      0    16K mmcsd    0   0:00   0.00% [mmcsd0boot0: mmc/sd]
>>    5 root          1 -16    -      0    16K crypto   0   0:00   0.00% [crypto returns 2]
>>   21 root          1 -16    -      0    16K mmcsd    0   0:00   0.00% [mmcsd0boot1: mmc/sd]
>>    6 root          1 -16    -      0    16K crypto   0   0:00   0.00% [crypto returns 3]
>>   22 root          3 -16    -      0    48K psleep   3   0:12   0.00% [pagedaemon]
>> 5270 root          1  20    0    14M  3780K CPU2     2   0:00   0.14% top -Saopid
>>  662 root          1  20    0    11M   680K select   0   0:00   0.00% /usr/sbin/rpcbind
>>    7 root          2 -16    -      0    32K -        0   0:00   0.00% [cam]
>>   23 root          1 -16    -      0    16K psleep   2   0:00   0.00% [vmdaemon]
>> 5255 root          1  20    0    12M  3092K wait     0   0:00   0.00% -sh (sh)
>>    8 root          1 -16    -      0    16K waitin   0   0:00   0.00% [sctp_iterator]
>>   24 root          3 -16    -      0    48K qsleep   3   0:12   0.01% [bufdaemon]
>>  712 root          1  52    0    12M   616K select   0   0:00   0.00% /usr/sbin/mountd -r
>>    9 root          1 -16    -      0    16K -        1   0:04   0.00% [rand_harvestq]
>>   25 root          1  20    -      0    16K vlruwt   0   0:04   0.00% [vnlru]
>>   10 root          1 -16    -      0    16K audit_   0   0:00   0.00% [audit]
>>   26 root          1  16    -      0    16K syncer   0   1:45   0.00% [syncer]
>>  714 root          1  52    0    12M   728K select   3   0:00   0.00% nfsd: master (nfsd)
>>   11 root          4 155 ki31      0    64K CPU0     0 144.6H 397.09% [idle]
>>  235 root          1  20    0    11M   564K select   3   0:00   0.00% dhclient: system.syslog (dhclient)
>>  715 root         32  52    0    11M  1120K rpcsvc   3   0:00   0.00% nfsd: server (nfsd)
>>   12 root         18 -52    -      0   288K WAIT     2   2:29   1.43% [intr]
>>  412 root          1  20    0    10M    72K select   2   0:00   0.00% /sbin/devd
>>  796 root          1  52    0    20M   672K select   0   0:00   0.00% /usr/sbin/sshd
>>   13 root          3  -8    -      0    48K -        1   0:11   0.00% [geom]
>>   14 root         20 -68    -      0   320K -        0   0:02   0.00% [usb]
>>  238 root          1  52    0    12M   416K select   1   0:00   0.00% dhclient: awg0 [priv] (dhclient)
>>   15 root          1 -16    -      0    16K -        0   0:00   0.00% [soaiod1]
>>  239 _dhcp         1  20    0    12M   484K select   1   0:00   0.00% dhclient: awg0 (dhclient)
>> 
>> (Basically the Pine64+ 2GB [aarch64] above was idle after boot other than
>> some runs of top.)
>> 
>> I see this oddity across architectures, for example amd64, powerpc64,
>> aarch64, armv7.
> 
> No wonder, it doesn't seem to have worked ever (?) as the compare_pid is
> simply not defined in compares list.  Try attached patch.
> <top.diff>

I'm a long term top user and it used to work. For example, when I was running
head -r340287 it worked as I remember. (I recreated such a vintage recently
for a test of something else. The -opid ordering was coherent as I remember,
unlike the above.)

It historically seemed to track the time order of process creation, even around the PID
number wrapping around. (So not a strict PID sort, at least for the PID shown.) This
was handy for monitoring buildworld buidkernel and port builds (all parallel).

I'll probably try the patch when I have a chance, even if it does strict PID number
order. Thanks.

===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
Received on Mon Dec 24 2018 - 22:38:42 UTC

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