How to release memory before Qt's Program finished ?

[lllturtle]

Hi all ,

i'm writing a really big(fat?) program ,
there's lots of function on this program ,
and i use a lot of widget / dialog box ...something like that ,
and i also add Qt::WA_DeleteOnClose ,
but seems like Qt will not release ram space back to system?

i've test to open all my function and close ,
at first my program run , it only take 1.7% of memory
after all the function open once , it take 2.2% ~ 2.3% of memory
and it keep in 2.2%~2.3% of memory usage , no matter the function opend twice or more times


Is there anyway to release Qt's memory back to system ?

thanks for any reply~

[Oleg]

Actually memory released on program exit by OS itself. But if you worry about memory usage during program work, then it seems you have memory leaks inside your code.

[FelixB]

don't worry. Just because you "delete" an object doens't mean the memory gets back to the operating system. your programm might keep this part reserved for future allocations.

[NullPointer]

Hi,

That is, the OS keep some memory for reallocations, it is for "increase" agility when doing that...
On Windows-based environment you can use the SetProcessWorkingSetSize, from Windows API... Sending the last two parameters a -1.
It will "removes as many pages as possible from the working set of the specified process." - http://msdn.microsoft.com/en-us/library/windows/desktop/ms686234%28v=vs.85%29.aspx.
This will not release any memory allocated by the program itself, just what OS think will be allocated again...

I don't know if there is a POSIX equivalent...


Hth.

[lllturtle]

Thanks for all your reply ,
i will try to find if there is any command like "SetProcessWorkingSetSize" under linux ,
and check my program if there is any memory leaks .:)