[tor-bugs] #6862 [arm]: arm does not show uptime

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#6862: arm does not show uptime
----------------------+-----------------------------------------------------
 Reporter:  drforbin  |          Owner:  atagar           
     Type:  defect    |         Status:  needs_information
 Priority:  normal    |      Milestone:                   
Component:  arm       |        Version:                   
 Keywords:  uptime    |         Parent:                   
   Points:            |   Actualpoints:                   
----------------------+-----------------------------------------------------

Comment(by atagar):

 Hm, the plot thickens...

 > I assume you mean ps -p TOR_PID -o cputime,etime,rss,%mem
 > not ...

 Oops, you're right. Copied the formatted string and forgot the escape.

 > attachment log...

 Here's the interesting bits...

 {{{
 9/16/2012 19:05:18 [DEBUG] Unable to query process resource usage from
 proc (stat file had an unexpected format: /proc/1804/stat)
 9/16/2012 19:05:19 [INFO] Failed three attempts to get process resource
 usage from proc, falling back to ps (stat file had an unexpected format:
 /proc/1804/stat)
 9/16/2012 19:05:19 [DEBUG] system call: ps -p 1804 -o
 cputime,etime,rss,%mem (runtime: 0.02)
 }}}

 So it's indeed using ps rather than the proc contents, and isn't reporting
 any issues.

 > here is return
 > TIME ELAPSED RSS %MEM
 > 00:01:22 14:38:37 55208 5.7

 That certainly looks like what I get...

 {{{
 atagar at morrigan:~$ ps -p 1563 -o cputime,etime,rss,%mem
     TIME     ELAPSED   RSS %MEM
 00:04:33       52:02 165256 16.2
 }}}

 ... and the util looks like it should be happy with it...

 {{{
 >>> import util.uiTools
 >>> util.uiTools.parseShortTimeLabel("14:38:37")
 52717
 }}}

 My theory is that the following is happening...

 - When the header panel first starts up it fetches static attributes
 (things that it only needs once). This includes tor's start time.

 - We see that a proc file exists, so try to use it to get the start time
 rather than ps. This fails (as mentioned in the log) and we cache the
 failed 'None' result in the header panel.

 To test this theory please make a text file with...

 {{{
 queries.useProc false
 }}}

 ... then run arm with 'arm --config /path/to/that/file'. If the uptime now
 appears then this is indeed the bug.

 Thanks for the catch! -Damian

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/6862#comment:5>
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