Brendan (btrotter.delete@this.gmail.com) on January 17, 2020 12:52 pm wrote:

> The difference is when you find out that you need to deal with a low memory problem - in a well defined
> place (as soon as you try to allocate the memory) where it's easy to control the circumstances, or "at
> any time, almost anywhere" where you have to worry about the least convenient circumstances.

So in your opinion, when ever one writes "new" or "malloc", there should be (serious) handler in case of OOM? Able to release some random caches and so on, if at all applicable to that particular software? And you consider that something everyone should spend time on?

> Note: If all computers had the same amount of RAM and no OS supported multi-tasking; then
> you wouldn't need to care much about this kind of thing. In other words; writing games for
> game consoles would be quite different to writing software for general purpose systems.

It is quite different. While on PC we never have to worry about OOM. We just put some minimum requirement and recommended memory amount on the box and hope the users understand that if they are running some background proces eating all their memory they need more to game at the same time. If we estimate wrong (and our estimates have to consider what more or less typical user will be running in addition to the game), what happens is that page file will be used a bit more than is nice and there may be some stuttering in game.

On consoles, we just have to stay within the limits. By far the best way to make sure of that is to just have some slack, not to do some crazy dance to try to free any extra buffers once OOM hits.

If we had some oracle that could tell us couple of frames beforehand that we are going to hit OOM unless something is done (that Oracle would need to be able consider more than just available memory, like for example memory fragmentation and size of upcoming allocations. And it must not be too pessimistic, because if it is, it's just better to use less memory all the time), then we could make several buffers smaller and reduce parallelism in some non-essential places. However, by the time we hit the OOM, it is pretty much impossible to start to do any of that without almost guaranteed deadlock.

-JLarja