Issue471

Title check time only if a finite timeout has been set
Priority feature Status resolved
Superseder Nosy List jendrik, malte
Assigned To jendrik Keywords
Optional summary

Created on 2014-09-20.11:27:05 by jendrik, last changed by jendrik.

Messages
msg3710 (view) Author: jendrik Date: 2014-10-08.11:50:24
Thanks for the review! Merged and pushed.
msg3690 (view) Author: jendrik Date: 2014-10-07.12:14:33
I updated the pull request with the suggested changes and added some comments on 
bitbucket.
msg3633 (view) Author: malte Date: 2014-10-04.19:34:14
Done.
msg3482 (view) Author: jendrik Date: 2014-09-20.14:54:14
Can you please check the code at 
https://bitbucket.org/jendrikseipp/downward/pull-request/20/issue471-avoid-
calling-times/diff ?
msg3480 (view) Author: malte Date: 2014-09-20.12:04:26
Addendum (rationale, perhaps we should mentions this in some abbreviated form in
the respective place in the code): calling times() presumably isn't really
expensive, but if we don't call it, we should get a much less cluttered output
of strace when we want to use it (as in issue469). In the experiment we did,
more than 99.9% of strace output was due to calls to "times" (or would have been
if we hadn't filtered it out).

In detail: in the airport blind search test we ran, 22908829 system calls were
to "times", while 12814 were to other functions. When filtering out "times", we
got a 708 KiB logfile. When not filtering times, we got a 2.6 GiB logfile.
msg3479 (view) Author: jendrik Date: 2014-09-20.11:27:05
We currently check the timers for the search and the iPDB hill-climbing 
regardless of whether a timeout has been set or not. This leads to many 
unnecessary calls to times() and should be changed.
History
Date User Action Args
2014-10-08 11:50:24jendriksetstatus: reviewing -> resolved
messages: + msg3710
2014-10-07 12:14:33jendriksetmessages: + msg3690
2014-10-04 19:34:14maltesetmessages: + msg3633
2014-09-20 14:54:14jendriksetstatus: chatting -> reviewing
messages: + msg3482
2014-09-20 12:04:26maltesetstatus: unread -> chatting
messages: + msg3480
2014-09-20 11:27:05jendrikcreate