Re: Linux doesn't seem to manage memory very well

On 01/05/2024 11:46, Marc Haber wrote:

James Harris <james.harris.1@gmail.com> wrote:

Not a question, just an observation.

 A freqently wrong one as well.
 

I say that Linux doesn't seem to handle memory well because my laptop
had 8GB RAM (which, frankly, Windows seems to find perfectly adequate
for a similar workload). Under Linux the RAM would fill up and then swap
space would be used. Then the machine would become largely unresponsive
- e.g. taking minutes to switch between windows.
>
So I upgraded the RAM. It now has three times as much (i.e. 24GB)! But
even so, RAM has still steadily filled up until reaching the full 24GB.
What's more, it's now showing 4.8GB of swap space in use.

 Linux swaps out lesser used pages anyway to make the backing memory
available for buffers or cache.
 Those people writing memory management are really smart. Smarter than
you and me together. Don't assume them being stupid.

It may be unwise to assume there's such expertise. A number of years ago I came up with what I thought was a sensible design for a paging system. I later found that it corresponded very closely to the one used in Windows and differed markedly from the paging system used in Linux. I remember thinking that the latter was not a good design and since then I've experienced problems with Linux when memory fills up which I tend to assume are down to the design of its paging system - hence the, admittedly provocative, title of this thread.
I can't remember much about it now and Linux may well have changed the way it handles page depletion but my experience as a Linux user seems to bear out my negative view of its page management.
Whatever the details, in defence of Linux it should be noted that the Linux design may have to cope with a much broader range of hardware - e.g. CPUs which have no accessed or dirty bits - whereas Windows was x86 focussed.
--
James Harris