io_uring is faster than mmap

Shouldn't you also compare to mmap with huge page option? My understanding is its presicely meant for this circumstance. I don't think its a fair comparison without it.

Respectfully, the title feels a little clickbaity to me. Both methods are still ultimately reading out of memory, they are just using different i/o methods.

The original blog post title is intentionally clickbaity. You know, to bait people into clicking. Also I do want to challenge people to really think here.

Seeing if the cached file data can be accessed quickly is the point of the experiment. I can't get mmap() to open a file with huge pages.

void* buffer = mmap(NULL, size_bytes, PROT_READ, (MAP_HUGETLB | MAP_HUGE_1GB), fd, 0); doesn't work.

You can can see my code here https://github.com/bitflux-ai/blog_notes. Any ideas?

MAP_HUGETLB can't be used for mmaping files on disk, it can only be used with MAP_ANONYMOUS, with a memfd, or with a file on a hugetlbfs pseudo-filesystem (which is also in memory).

> MAP_HUGETLB can't be used for mmaping files on disk

False. I've successfully used it to memory-map networked files.

My bad, don't use `MAP_HUGETLB`, just use `MAP_HUGE_1GB`.

See a quick example I whipped up here: https://github.com/inetknght/mmap-hugetlb

Adding MAP_HUGE_1GB and not MAP_HUGETLB does compile and run for me. Not convinced that its' actually doing anything. Performance is the same.