On 2015-11-12 01:30, Theo de Raadt wrote:
I find this conversation puzzling, since even back in BSD 4.3, read()
was
actually implemented by memory mapping the underlying file.
That is an wildly incorrect description of the 4.3 BSD buffer cache,
furthermore 4.3 lacked a working mmap() to hit the coherency issue.
Wait, so if you make a read-only mmap(), will the buffer in OpenBSD be
"unified" in the sense that fwrite():s always will be immediately
visible in the memory mapped version?
(This is what I understood that Howard suggested would apply from BSD
4.3 and on and Theo now said not was correct, so, my question is if that
behavior was introduced later in OpenBSD.)
