Comment by Asmod4n
3 days ago
How can one memcpy from a fd to a socket? I don’t touch the bytes in userspace, I just tell the kernel to send them out.
3 days ago
How can one memcpy from a fd to a socket? I don’t touch the bytes in userspace, I just tell the kernel to send them out.
So why would you mmap?
to not let the bytes i forward enter userspace, i serve from the page cache for the asset path, directly from a zip file.
i open the file, mmap it, close it and tell io_uring_prep_send which bytes from the mapping to send, this also saves me from a possible SIGBUS cause the access to the mmap happen inside the kernel, and when a SIGBUS would happen in userspace the kernel just reports a shorter send in cqe->res