HugeTLB and mlock support?

[dovahcrow]

Hi, I'm trying to add hugetlb and mlock support for the shared memory region to further increase the performance at https://github.com/dovahcrow/shmem-ipc. I can create a PR if you want to make these changes into the main repo.

Note that the implementation is not finished: I am stuck at using set_len to increase the size of the memfd (https://github.com/dovahcrow/shmem-ipc/blob/master/src/mem.rs#L81): it always returns EINVAL, and I haven't found a solution yet. By reading the Linux source code, it turned out hugetlb does not need set_len!

Any suggestion is welcomed!

[diwic]

Sounds interesting! What performance gains do you expect from this?

Also, I guess both will be configurable and turned off by default? At least mlock should be opt-in. Maybe hugetlb would depend on the buffer size or something, I'm not very familiar with hugetlb and what pros and cons that has.

[dovahcrow]

Yep, they are optional in my implementation. I didn't test the performance gain. These two just seems to me a quite standard way to have high-performance shmem

[diwic]

If you already have an implementation I'd be happy to review it.