A lot of measures are preventative, and kind of have to be.
Consider the hypothetical scenario of being totally out of memory. I mean completely: not a single page free, all buffers and caches flushed, everything else taken up by data that cannot be evicted. So in result, you cannot spawn a process. You cannot do any filesystem operations that would end up in allocations. You can't even get new page tables.
Hence things like Linux's OOM killer, which judiciously kills processes--not necessarily the ones you would like killed in such a situation. And again, a lot of preventative measures to not let it come that far.
Our Turing Machines still want infinite tapes, in a way.
Consider the hypothetical scenario of being totally out of memory. I mean completely: not a single page free, all buffers and caches flushed, everything else taken up by data that cannot be evicted. So in result, you cannot spawn a process. You cannot do any filesystem operations that would end up in allocations. You can't even get new page tables.
Hence things like Linux's OOM killer, which judiciously kills processes--not necessarily the ones you would like killed in such a situation. And again, a lot of preventative measures to not let it come that far.
Our Turing Machines still want infinite tapes, in a way.