Giving more CPU time to a swapping process?

Chuck Swiger cswiger at
Thu Apr 6 13:53:39 UTC 2006

Karl Ma wrote:
> The process is so memory-hungry that it starts swap after the physical RAM
> max out. (To be exact, I've lowered the per-process limitation to make this
> possible).

What did you lower, exactly?  If you reduce the max resident datasize 
needlessly, you're going to make your program swap more and run much slower.

> 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.

Yes, because the task isn't using much CPU, it's entirely I/O bound.

> 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.

Won't help.  Add more RAM, or adjust the program to be more clever about the 
use of memory, possibly by using Numeric/numarray.

The size of your python process is surprising to me, python tends to run 
relatively lightweight process sizes even when handling large data sets (ie, 
 > 1GB of data per day)...


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