From: Linus Torvalds
> Sent: 02 February 2018 22:57
...
> I also wonder if there are any automated tools that try to find these
> kinds of crazy things. I suspect a lot of our build times is the poor
> compiler just reading and parsing header files over and over again,
> and a lot of them are probably not needed.
I've counted system calls during a NetBSD kernel build, I imagine Linux is
much the same.
Most of the calls were open(), and most of those failing opens.
I suspected that most came from searching the -I path to find headers.
Build over NFS and the cost is even more significant (every directory
name in the path (used to) require an NFS message exchange).
David
