[Info-vax] Running Alpha VMS under the ES40 emulator

[Johnny Billquist]

On 2013-10-13 02:47, Simon Clubley wrote:
> On 2013-10-12, Johnny Billquist <bqt at softjar.se> wrote:
>> On 2013-10-12 17:27, Simon Clubley wrote:
>>> When using Firefox heavily while doing some research, I also encounter
>>> that same problem after a period of time.
>>
>> This does not really smell like memory leaks or big bugs, just the
>> normal expected behavior. If this is all you get, then it would be
>> reasonable for things to be stable over night when the system is not
>> touched.
>>
>> Ah well. I do not feel like arguing over this. I *know* that the nightly
>> jobs will push processes out of memory for file cache use.
>> You can easily simulate it by just (as root) do a "find / -name '*.core'
>> -print" twice, and once they have completed, check how responsive your
>> web browser is.
>
> Oh, I agree with you on that; it's just that the same thing happens when
> I don't do anything like that.
>
> One would expect memory to be reclaimed after a period of time as tabs
> and windows are closed. Instead, apart from some minor changes, the
> overall trend appears to be generally upwards and a continued slowing
> of Firefox even after multiple tabs and windows have been closed.

Memory usage and allocation patterns in most programs means that it's 
easy to allocate new chunks of memory, but it is hard to ever return any 
memory to the OS.
The OS never reclaims anything until the program exits. Programs 
explicitly have to give the memory back to the OS. Normal memory 
allocation routines don't return any memory to the OS. They keep it 
around for later. (And because it is damned hard to return the memory.)

	Johnny

-- 
Johnny Billquist                  || "I'm on a bus
                                   ||  on a psychedelic trip
email: bqt at softjar.se             ||  Reading murder books
pdp is alive!                     ||  tryin' to stay hip" - B. Idol