Show HN: Recursive COW Pages in Userspace

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13 pointswheybags2 comments

This is neat, but the Linux kernel kind of has a built in mechanism for this — userfaultfd (see, the following for when the capability to implement CoW was added: https://lwn.net/Articles/777258/).

The article does highlight that the capability described is implemented in userspace, but quite a bit of what’s required to implement segfaults happens in kernel space. I’d argue that userfaultfd is equally in userspace to signal handlers.

Oh nice! I didn't really look into a linux implementation, as my initial curiosity was sated by the time I finished the windows version, but it's cool to know there's a more "proper" option there.

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