On 2016-05-10, Pau Amaro-Seoane <pau.amaro.seo...@gmail.com> wrote: > :datasize-cur=infinity:\ > :datasize-max=infinity:\
These settings make it easier to run your machine out of RAM which will probably hang or crash the kernel if it happens (OpenBSD doesn't deal with that situation well). I'd often go for somewhere around a third of the amount of physical RAM for datasize-cur on a workstation with a reasonable but not massive amount of memory (to reduce the chance of two large-ish concurrent processes running me out of memory) but it depends what the machine is doing. > :stacksize-cur=32M:\ That's a *lot* of stack to allow for one process. "ps -o ssiz -uwax | sort -n" will show you how much you're currently using in your processes. You're unlikely to need more than 8M unless you're using some program that places inadvisable amounts of data on the stack rather than in malloc'd memory, or does very deep recursion (functions that call themselves within limits; this is a perfectly valid programming technique and each function doesn't take much space on the stack - going above 8MB for this would be already be excessive and more likely due to a bug than found in normal use). I'm struggling to find anything using more than 500K of stack in one process, and the majority of things around under 200K; by the time the default stack limit is exhausted a process is already likely to be doing something pretty stupid or is broken (runaway recursive process stuck in a loop). As an aside: The stack holds return addresses for function calls and other information so that when a function has finished it returns control to the correct place - this is something that attackers often try to subvert, to return control to code of their choosing rather than the expected place - and also holds "automatic" variables i.e. ones defined directly in functions - not global variables and not malloced. You can find much better explanations online, these seem pretty good: http://duartes.org/gustavo/blog/post/anatomy-of-a-program-in-memory/ http://duartes.org/gustavo/blog/post/journey-to-the-stack/ and there are some other bits in http://duartes.org/gustavo/blog/category/software-illustrated/ if you're interested in learning more about this sort of thing. _______________________________________________ Openbsd-newbies mailing list Openbsd-newbies@sfobug.theapt.org http://mailman.theapt.org/listinfo/openbsd-newbies
