Moving the kernel to modern C [LWN.net]

Moving the kernel to modern C

Posted Mar 3, 2022 23:54 UTC (Thu) by Wol (subscriber, #4433)
In reply to: Moving the kernel to modern C by dvdeug
Parent article: Moving the kernel to modern C

I thought it started with a suggestion that OO languages (C++) be used in the kernel.

In which case, OO-bashing is justified. OO *IS* useful, but in the kernel when a few extra bytes of object code can cost you dearly in page faults etc, those faults are pretty fatal for the concept. THAT was the purpose of the bashing ...

Cheers,
Wol

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Moving the kernel to modern C

Posted Mar 4, 2022 9:42 UTC (Fri) by mpr22 (subscriber, #60784) [Link]

The kernel embraced the size overheads of OO back in the 1990s, and C++'s OO model is just as much "pay for what you use" as the one the kernel uses.

If a class has no virtual members, it doesn't need a function table and doesn't have function-pointer dispatch overheads.

If it has some virtual members, only the members that are virtual have to be identified in the function table and called through function pointers.