[blattimwind]

Cleaning up memory is an antipattern for many tools, especially of the EVA/IPO model (input-process-output). For example, cp(1) in preserve hard links mode has to keep track of things in a table; cleaning it up at the end of the operation is a waste of time. Someone "fixed" the leak to make valgrind happy and by doing so introduced a performance regression. Another example might be a compiler; it's pointless to deallocate all your structures manually before calling exit(). The kernel throwing away your address space is infinitely faster than you chasing every pointer you ever created down and then having the kernel throw away your address space. The situation is quite different of course if you are libcompiler.

[saagarjha]

> The kernel throwing away your address space is infinitely faster than you chasing every pointer you ever created down and then having the kernel throw away your address space.

In this case you normally want to allocate an arena yourself.

[atq2119]

> Another example might be a compiler; it's pointless to deallocate all your structures manually before calling exit().

And now the compiler can no longer be embedded into another application, e.g. an IDE.

It's a reasonably pragmatic way of thinking, but beware the consequences. One benefit of working with custom allocators is that you can have the best of both worlds. Unfortunately, custom allocators are clumsy to work with.

[badsectoracula]

Solve the problem you have now, not the problem you may not have later. You can worry about that when the time comes, if it ever comes.

In the case of compiler, one solution would be to replace all calls to `malloc` with something like `ccalloc` that simply returns pieces of a `realloc`'d buffer which is freed after the in-IDE compiler has finished compiling.

[zozbot234]

"Throwing away" a bunch of address space also happens when freeing up an arena allocation, and that happens in user space. This means that you might sometimes be OK with not managing individual sub-allocations within the arena, for essentially the same reason: it might be pointless work given your constraints.

[ufo]

Is there is a way to tell Valgrind that a certain memory allocation is intentionally being "leaked", and should not produce a warning?

[blattimwind]

https://valgrind.org/docs/manual/manual-core.html#manual-cor...