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Date: Thu, 16 Sep 2004 21:58:33 -0500 (CDT)
From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us>
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On Thu, 16 Sep 2004, Bob Friesenhahn wrote:

> I have attached source for a small test program I used to see how systems 
> behave under load when using memory mapped files.  Naturally, documentation 
> is poor and the code is meant for hacking. :-)

Here are some results just obtained from running the mmap file update 
benchmark on some modern systems with fast CPUs and fast disks. 
Maybe someone can modify the benchmark to use stdio or read/write and 
see how performance compares with mmap?

Solaris 9:

% time ./mmaptest 16
File length = 6442450941
Stride      = 131072
./mmaptest 16  4.92s user 50.81s system 44% cpu 2:06.55 total

Linux 2.6.7:

% time ./mmaptest 16
File length = 6442450941
Stride      = 65536
./mmaptest 16  2.54s user 13.28s system 11% cpu 2:17.95 total

FreeBSD 5.0:

% time ./mmaptest 16
File length = 6442450941
Stride      = 65536
./mmaptest 16  4.12s user 76.41s system 35% cpu 3:46.18 total

======================================
Bob Friesenhahn
bfriesen@simple.dallas.tx.us
http://www.simplesystems.org/users/bfriesen
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