I get that you can do this in response to a system call (the one issued in step 1). You could avoid blocking in Linux as well using madvice() and mincore(), as pointed out in the comments to the article. However, once you get an actual page fault, the only option is to block the process.
> I get that you can do this in response to a system call (the one issued in step 1). You could avoid blocking in Linux as well using madvice() and mincore()
Yes, but the one thing they don't give you is notification the data is in memory. Do you really want to spin a hot loop calling mincore?
> However, once you get an actual page fault, the only option is to block the process.
The only way to receive an event would be from a signal, like SIGSEGV. There is no way to hook a jump instruction up to kqueue. In any case, this would mean writing specific code to handle the case, implying it is not simply a difference of the FreeBSD kernel vs the Linux kernel.
