[Info-vax] Memory Management (was Re: Running Alpha VMS under the ES40 emulator)

[JF Mezei]

On 13-10-13 22:06, Johnny Billquist wrote:

> Indeed. But if you look with top, or other system tools, at the virtual 
> memory size, this memory is in there. Which is why you should not 
> necessarily put too much significance in how much virtual memory a 
> process have allocated.


A properly written browser would have it "locally" release all memory
associated with a web page when that tab is closed. This may not be
reflected in the process virtual memory.

And when a new tab and web page is opened, that locally released memory
can be re-used to build the new web page display, thus no need to go to
the OS and request more memory be allocated to the process.

BUT, when a process fails to locally deallocate memory, its local free
pool is too small to allow for a new page to be displayed, at which
point, the process asks the OS for more virtual memory.

malloc and free are "retail" operations that work on a local pool of
memory which is obtained in wholesale from the operating system.