The Linux kernel's inability to gracefully handle low memory pressure

Re:The Linux kernel's inability to gracefully handle low mem... by joosters on Tuesday August 06, 2019 @05:57AM (#20623766)

It's the transparency of memory allocation that makes it so difficult to deal with failures. Even 'trivial' library functions could allocate memory, hell even calling a tiny dumb function might cause the stack to require a new page of memory, leading to failure. Just checking that all malloc calls check for NULL isn't even half of it.

Exception handlers won't save you either. Unless you consciously consider every memory allocation failure, your exception handlers will be too high level and result in your program either aborting by itself or becoming unusable. Did you pre-allocate enough resources to pop up an 'out of memory' error window? Good luck failing gracefully.

Memory allocation is special.

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Re:The Linux kernel's inability to gracefully handle low mem... by ensiferum on Tuesday August 06, 2019 @06:13AM (#20623841)

Yes, it's an imperfect world and you can't control what happens in a library but the attitude "it doesn't matter if my code is messed up or not, some library will still do the wrong thing" doesn't help. All you can do is make your code work properly and that's what you (and everyone else) should do.

Again it's imperfect world saying that "it won't work because x, y, z will happen" is not the right attitude and is bad attitude. Most of your code should treat it as just a resource allocation failure and in a sane program that is indicated by propagating an exception up the stack. Now you might be right that the program might fail when it'd be the time to display a message box to the user or whatever. But somewhere in the middle layers of the code you don't have that context, you don't know that it will fail. Therefore that part of your code really should be (exception) neutral just like in any resource allocation case.

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Re:The Linux kernel's inability to gracefully handle low mem... by cies on Tuesday August 06, 2019 @10:49AM (#20625632)

> Memory allocation is special.

I think the Zig lang treats it as special, therefore making you write code that handles the case that a malloc fails explicitly.

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