[lcheylus]

It's more accurate to use sysctl with uvmexp struct (statistics about the UVM memory management system) to get pagesize and free pages, than using calls to C.sysconf.

See OpenBSD uvm/uvmexp.h include file for definition of uvmexp struct.

Tests OK on OpenBSD current/amd64

get_free_memory.v:

// Get free memory (vlib/runtime/free_memory_impl*.c.v)

import os
import runtime

fn main() {
        println('OS: ${os.user_os()}')

        total := runtime.total_memory()
        free := runtime.free_memory()

        println('total memory: ${total}')
        println('free  memory: ${free}')
}

$ ./v run ~/tmp/get_free_memory.v 
OS: openbsd
total memory: 4278042624
free  memory: 1475702784

[huly-for-github]

Connected to Huly®: V_0.6-22802

[spytheman]

Is there a difference in the reported sizes before/after the patch?

[lcheylus]

Is there a difference in the reported sizes before/after the patch?

Yes, there is a difference in the reported number of free pages between direct call to sysctl and C.sysconf for _SC_AVPHYS_PAGES => call via libc with some additional memory allocations.

See https://github.com/openbsd/src/blob/987e6c5a8530c1fc5f890c92b40b9e16b89c7264/lib/libc/gen/sysconf.c#L451-L460

[spytheman]

Thank you.