Re: InfoWorld web server shootout
Larry McVoy (lm@neteng.engr.sgi.com)
Wed, 09 Jul 1997 14:23:18 -0700
: You're clearly
: aware that going straight from the page cache via mmap/write is a big
: win but you claim that you have to pay for the mapping so much that
: you'd need to cache it. Have you verified/benchmarked that or is it
: just a gut feeling (or perhaps tested on other Unices)? I haven't
: tested it myself but
I have. See http://reality.sgi.com/lm/lmbench/ go to the link marked "new"
and look at file reread bandwidths for the PC. There are two lines that
start out low and go up to match the rest. Those two are open-to-close
MB/sec costs as a function of file size. Tells you all you want to know.
The short summary is that mmap starts being a win around 8K files.
--lm