<!-- Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009, 2013, 2014 The President and Fellows of Harvard College. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the University nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. --> <html> <head> <title>psort</title> <body bgcolor=#ffffff> <h2 align=center>psort</h2> <h4 align=center>OS/161 Reference Manual</h4> <h3>Name</h3> <p> psort - concurrent file system test </p> <h3>Synopsis</h3> <p> <tt>/testbin/psort</tt> [<tt>-p</tt> <em>numprocs</em>] [<tt>-k</tt> <em>numkeys</em>] [<tt>-r</tt> | <tt>-s</tt> <em>randomseed</em>] </p> <h3>Description</h3> <p> <tt>psort</tt> does an on-disk parallelizing sort of a large number of randomly generated integers. It is loosely based on some real parallel sort benchmarks. </p> <p> Be aware of its size vs. the size of your buffer cache, and adjust its size as needed. Running it so it fits entirely in cache and running it so it overflows the cache are both valid stress tests, but have quite different characteristics. </p> <h3>Options</h3> <ul> <li> <tt>-k</tt> Set the number of integers. Default is 131072. <li> <tt>-p</tt> Set the number of processes. Default is 4. <li> <tt>-r</tt> Get a random seed from the <tt>random:</tt> device. <li> <tt>-s</tt> <em>randomseed</em> Choose an explicit random seed. </ul> <p> The memory footprint depends on the number of processes and the per-process work buffer size (which can be changed at compile time); the file system footprint depends on the number of integers. Specifically, the memory footprint is the number of processes (default 4) times the buffer size (default 384K), and the file size is the number of integers (default 131,072) multiplied by the size of an integer (here 4) multiplied by the maximum number of copies of the data that appear at once, which is 3, so 1.5 MB. </p> <p> Note that the parent psort process does not serve as one of the worker processes; it also has a work buffer, but doesn't use it. Also note that it forks several (six) sets of subprocesses in the course of execution. A virtual memory system that doesn't support the zerofilled page optimization will both use 1/n more memory for the extra work buffer and also incur a fairly large cost copying it in every fork. Also, because of the large number of forks the amount of RAM required to run psort using dumbvm is likely prohibitive. </p> <h3>Requirements</h3> <p> <tt>psort</tt> uses the following system calls: <ul> <li> <A HREF=../syscall/open.html>open</A> <li> <A HREF=../syscall/dup2.html>dup2</A> <li> <A HREF=../syscall/read.html>read</A> <li> <A HREF=../syscall/write.html>write</A> <li> <A HREF=../syscall/lseek.html>lseek</A> <li> <A HREF=../syscall/close.html>close</A> <li> <A HREF=../syscall/stat.html>stat</A> or <A HREF=../syscall/fstat.html>fstat</A> (optional) <li> <A HREF=../syscall/remove.html>remove</A> <li> <A HREF=../syscall/fork.html>fork</A> <li> <A HREF=../syscall/execv.html>execv</A> <li> <A HREF=../syscall/waitpid.html>waitpid</A> <li> <A HREF=../syscall/_exit.html>_exit</A> </ul> It also execs <A HREF=../bin/cat.html>cat</A>. </p> <p> <tt>psort</tt> should be able to run properly on SFS filesystems once the basic system calls are implemented. However, you may need to adjust its workload size depending on the level of large-file support you have in SFS. </p> <p> <tt>psort</tt> will mostly run on emufs, but there isn't really much point in that. </p> </body> </html>