How to generate 'fake' memory load?

unix_95054 has asked for the wisdom of the Perl Monks concerning the following question:

Hi, I know that it is possible to generate dummy/fake CPU load using perl. Here is how to do that:

perl -e 'while (--$ARGV[0] and fork) {}; while () {}' 4

Could someone please let me know how to generate fake or dummy load on memory for a Unix server? This will be used for a small test. Thanks, Unix Lover

Comment on How to generate 'fake' memory load?

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Re: How to generate 'fake' memory load? by kyle (Abbot) on Aug 04, 2008 at 19:32 UTC
You just want to allocate a lot of memory? `perl -e '$m = "x" x 1_000_000; sleep 120';` [download] (Holds its memory for two minutes and exits.)	[reply] [d/l]
Re: How to generate 'fake' memory load? (hogs) by tye (Sage) on Aug 04, 2008 at 20:12 UTC
See also: one-liner hogs. There are at least two flavors of "memory load". Allocating a large string mostly just ends up consuming swap space. Continually updating the contents of a large string can consume physical memory (if the process doesn't just lose out in the fight to keep access to that limited resource). - tye	[reply]
Re^2: How to generate 'fake' memory load? (hogs) by tilly (Archbishop) on Aug 04, 2008 at 21:09 UTC
Reading can do the same thing as updating. For instance try the following to allocate about 10 MB of memory and actually keep it active: `perl -e '$_ = "x" x 10_000_000; $_ .= "y"; sleep 1 while /y/;'` [download] Update: kyle caught a typo where I switched variable names. Fixed.	[reply] [d/l]
Re: How to generate 'fake' memory load? by Joost (Canon) on Aug 04, 2008 at 20:13 UTC
You really should decide if you want memory load or cpu load. Anyway, for CPU load, this works fine: `perl -e '1 while 1'` [download] Perhaps fork() once first, for each CPU. On re-read: what kyle said. "What should it profit a man, if he should win a flame war, yet lose his cool?"	[reply] [d/l]