different memory size in different OS

[joseph_quanzhou]

dear all,
it is a question about the memory size that application takes in
different OS,
it takes 400MB in the HP Unix V11.1,but it olny take 20-40MB in linux!
I will appreciate that if anybody can tell me how this happens?
Thanks!

 

[pravi4u]

this is strange!

 

[Chris Uppal]

it takes 400MB in the HP Unix V11.1,but it olny take 20-40MB in linux!

Some speculation (I.e. guesswork ;-)

It could be an artefact of the way the OS reports memory usage. I don't know
what happens on HP Unix or Linux, but under Windows the JVM "reserves" some
memory for future use. That's to say it tells the OS something like "I may
need up to 400M in the future, but right now I only need 25M". So, depending
on what data you look at, you may see the JVM apparently using 400M, or only
25M (or, rather, those figures plus whatever is needed for stuff that isn't
dynamically allocated in that way).

That might be what's happening on your two systems. But, I suppose, another
possibility is that HP doesn't have an equivalent to the Windows feature, but
that Linux does have, and so the JVM on HP is forced to allocate all the memory
it /might/ need up-front in case it turns out to have to use it later.

-- chris

 

[=?ISO-8859-1?Q?Arne_Vajh=F8j?=]

it is a question about the memory size that application takes in
different OS,
it takes 400MB in the HP Unix V11.1,but it olny take 20-40MB in linux!
I will appreciate that if anybody can tell me how this happens?

What exactly do you measure ?

Arne

 

[joseph_quanzhou]

thanks you for your answers!
so,do you think it is ok and I don't have to do something with this? or
there is some ways to cut down the memory the application takes?

 

[Chris Uppal]

so,do you think it is ok and I don't have to do something with this? or
there is some ways to cut down the memory the application takes?

Remember, I did warn you that I was speculating.

However, this seems to be a case where you should check the OS-specific
documentation, and if you can't find anything there then just don't worry about
it unless the memory consumption is causing /actual/ problems.

-- chris