Google Answers Logo
View Question
 
Q: How to speed up swapping in FreeBSD? ( No Answer,   0 Comments )
Question  
Subject: How to speed up swapping in FreeBSD?
Category: Computers > Operating Systems
Asked by: assistance-ga
List Price: $20.00
Posted: 06 Apr 2006 01:37 PDT
Expires: 06 Apr 2006 08:38 PDT
Question ID: 716063
Hi,

I have a python program running on freebsd, doing a heavy indexing job
involving a mega size array.

The process is so memory-hungry that it starts to swap after the
physical RAM max out.

However, when I use top to monitor the status, the STATE of the
process started to stay as "swread" for most of the time (instead of
RUN before using swap) and its priority has dropped to -20; and the
corresponding WCPU drops to around 1% only. And the CPU consumption
time in total (for the whole job) would only increase a minute or two
even the process has been running for more than a few hours.

In Windows XP, which has less per-task resource restriction (I
guess?), I did successfully complete the task on the same hardware
machine; although it takes more than 30 mins.

How can I push up the priority of the whole paging task? How can I
allocate more CPU attention to this process? I've tried using "nice"
but it does not help.

Please refer to the below top's snapshots at different times. (A) is
earlier than (B), and so on.

Thanks for your help in advance.



= (A) =
last pid:   766;  load averages:  0.66,  0.21,  0.11    up 0+00:19:54  23:23:04
63 processes:  2 running, 61 sleeping
CPU states: 96.6% user,  0.0% nice,  3.4% system,  0.0% interrupt,  0.0% idle
Mem: 341M Active, 35M Inact, 98M Wired, 704K Cache, 91M Buf, 522M Free
Swap: 998M Total, 998M Free

PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
751 root        1 118    0   245M   244M RUN      0:59 96.57% python

= (B) =
last pid:   792;  load averages:  1.02,  0.70,  0.36    up 0+00:24:20  23:27:30
62 processes:  2 running, 60 sleeping
CPU states: 92.5% user,  0.0% nice,  6.0% system,  1.5% interrupt,  0.0% idle
Mem: 766M Active, 67M Inact, 115M Wired, 45M Cache, 109M Buf, 3636K Free
Swap: 998M Total, 37M Used, 962M Free, 3% Inuse, 17M Out

PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
751 root        1 128    0   744M   743M RUN      5:14 94.63% python

= (C) =
last pid:   792;  load averages:  1.06,  0.81,  0.43    up 0+00:25:54  23:29:04
62 processes:  2 running, 60 sleeping
CPU states: 95.5% user,  0.0% nice,  4.1% system,  0.4% interrupt,  0.0% idle
Mem: 849M Active, 2868K Inact, 115M Wired, 28M Cache, 109M Buf, 1656K Free
Swap: 998M Total, 95M Used, 903M Free, 9% Inuse, 236K Out

PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
751 root        1 128    0   848M   841M RUN      6:42 91.46% python

= (D) =
last pid:   792;  load averages:  1.15,  0.87,  0.47    up 0+00:26:36  23:29:46
62 processes:  1 running, 61 sleeping
CPU states: 28.6% user,  0.0% nice, 18.8% system,  1.5% interrupt, 51.1% idle
Mem: 843M Active, 5380K Inact, 116M Wired, 31M Cache, 109M Buf, 1656K Free
Swap: 998M Total, 142M Used, 856M Free, 14% Inuse, 932K In, 56M Out

PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
751 root        1 -20    0   878M   841M swread   7:14 79.05% python

= (E) =
last pid:   817;  load averages:  0.06,  0.36,  0.36    up 0+00:32:31  23:35:41
62 processes:  1 running, 61 sleeping
CPU states:  4.9% user,  0.0% nice,  7.1% system,  0.0% interrupt, 88.0% idle
Mem: 803M Active, 76M Inact, 88M Wired, 28M Cache, 109M Buf, 1656K Free
Swap: 998M Total, 234M Used, 765M Free, 23% Inuse, 3148K In, 2284K Out

PID USERNAME  THR PRI NICE   SIZE    RES STATE    TIME   WCPU COMMAND
751 root        1 -20    0   915M   756M swread   8:01  1.03% python
Answer  
There is no answer at this time.

Comments  
There are no comments at this time.

Important Disclaimer: Answers and comments provided on Google Answers are general information, and are not intended to substitute for informed professional medical, psychiatric, psychological, tax, legal, investment, accounting, or other professional advice. Google does not endorse, and expressly disclaims liability for any product, manufacturer, distributor, service or service provider mentioned or any opinion expressed in answers or comments. Please read carefully the Google Answers Terms of Service.

If you feel that you have found inappropriate content, please let us know by emailing us at answers-support@google.com with the question ID listed above. Thank you.
Search Google Answers for
Google Answers  


Google Home - Answers FAQ - Terms of Service - Privacy Policy