Subject: Re: cp(1) vs. UVM/UBC
To: Andy Isaacson <>
From: Matthias Buelow <>
List: tech-userlevel
Date: 07/21/2001 21:46:29
Andy Isaacson writes:

>degenerate cases.  For example, Solaris /bin/cp does the mmap/write
>trick (with a madvise in there too), and if you /bin/cp a file to
>/dev/null, it doesn't even bother to fault in the pages.  For example, I
>can cp /some/nfs/directory/100mb_file /dev/null in
>real    0m0.29s
>user    0m0.00s
>sys     0m0.05s

*cough* this somehow reminds me of the tale where a few system engineers,
after careful analysis with a profiler, optimized an operating system's
idle loop.... but oh, well, what do I care.