[ntp:questions] Ntpd in uninterruptible sleep?

A C agcarver+ntp at acarver.net
Wed Oct 26 06:41:22 UTC 2011


On 10/25/2011 20:46, Steve Kostecke wrote:
> On 2011-10-25, A C<agcarver+ntp at acarver.net>  wrote:
>> On 10/25/2011 14:53, unruh wrote:
>>>
>>> ?? So why are you using X at all? Xterm can surely be replaced by the
>>> console. And xclock by running date to tell you what time the machine
>>> thinks it is (I assume you use that to check to see if ntpd has stopped
>>> controlling the clock)
>>
>> A few reasons for not using console:
>> 1. I don't have a monitor to devote to the machine that works at
>> standard Sun framebuffer refresh rates.  With the odd resolution and
>> rate of the CG6 most inexpensive LCDs just fall over and refuse to sync.
>>    My one monitor that can sync is also the nice one that I use for my
>> regular desktop machine.
>>
>> 2. Even with a monitor on the machine there's a bug in the console
>> driver in NetBSD that locks up the console getty if redraws occur too
>> quickly.  It's a known bug on the sparc hardware but hard to track down.
>>    It doesn't affect anything else except the getty on the console.
>>
>> 3. I can leave the Xterm on my screen on my everyday machine and be able
>> to use it when I need to without needing to reach for another keyboard.
>>    Plus anything I do on the machine, especially during debugging right
>> now, I can copy and paste to post to the list or save for later.
>
> Wouldn't it be easier to just open an Xterm on your everyday machine and
> ssh into the time server?
>

That's almost what I'm doing.  I just happen to have a quick icon on my 
regular machine that creates an ssh session and sends back an xterm. 
It's really not causing much if any overhead on the Sun machine.  Here's 
the output from top with top itself running inside the xterm so 
refreshes are occuring and causing the xterm and ssh to use a bit of 
CPU.  There isn't much load at all, mostly the garbage collector.  I 
haven't had a chance yet to put the memory back in the system so it's 
still running with 16 MB.

> load averages:  0.17,  0.06,  0.01;    up 16+12:49:20          06:38:54
> 22 processes: 21 sleeping, 1 on CPU
> CPU states: 11.4% user,  0.0% nice,  7.3% system,  4.9% interrupt, 76.3% idle
> Memory: 4824K Act, 2440K Inact, 300K Wired, 2180K Exec, 1412K File, 460K Free
> Swap: 128M Total, 8820K Used, 120M Free
>
>   PID USERNAME PRI NICE   SIZE   RES STATE      TIME   WCPU    CPU COMMAND
>     0 root     125    0     0K 5392K cachegc  158:13  3.56%  3.56% [system]
> 29574 root      85    0  5416K  896K pause      1:54  1.76%  1.76% ntpd
>   408 agcarver  85    0    11M  752K select     2:40  1.56%  1.56% sshd
>  1047 root      85    0  3448K  496K wait       0:23  0.98%  0.98% bash
>   533 agcarver  85    0    11M  668K select   118:57  0.78%  0.78% sshd
>   323 nobody    90  -10    13M  576K select    41.9H  0.00%  0.00% gpsd
>   415 agcarver  85    0  7172K  504K select   105:06  0.00%  0.00% xclock
>   410 agcarver  85    0  7328K  836K select    31:01  0.00%  0.00% xterm
>   335 root      85    0  5708K  260K kqueue     3:37  0.00%  0.00% master
>   391 postfix   85    0  5720K  308K kqueue     2:39  0.00%  0.00% qmgr
>   400 root      85    0  3372K  244K nanoslp    1:43  0.00%  0.00% cron
>   115 root      85    0  3468K  288K kqueue     1:23  0.00%  0.00% syslogd
>   508 root      83    0    11M    0K netio      0:06  0.00%  0.00% <sshd>
>   363 root      85    0    11M    0K netio      0:05  0.00%  0.00% <sshd>
>    34 root      85    0  3292K    0K pause      0:01  0.00%  0.00% <csh>
>   926 root      43    0  3624K 1112K CPU        0:00  0.00%  0.00% top
> 28716 postfix   85    0  5708K  616K kqueue     0:00  0.00%  0.00% pickup
>     1 root      85    0  3472K   60K wait       0:00  0.00%  0.00% init
>   249 root      85    0  7592K    0K select     0:00  0.00%  0.00% <sshd>
>   421 agcarver  85    0  3448K    0K wait       0:00  0.00%  0.00% <bash>
>   402 root      85    0  3444K    0K ttyraw     0:00  0.00%  0.00% <getty>
>   374 root      83    0  3584K    0K kqueue     0:00  0.00%  0.00% <inetd>



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