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From dgau...@hyperreal.org
Subject cvs commit: apachen/htdocs/manual/misc perf-tuning.html
Date Fri, 24 Oct 1997 09:39:19 GMT
dgaudet     97/10/24 02:39:19

  Modified:    htdocs/manual/misc perf-tuning.html
  Log:
  document MMAP_SEGMENT_SIZE
  
  Revision  Changes    Path
  1.2       +16 -9     apachen/htdocs/manual/misc/perf-tuning.html
  
  Index: perf-tuning.html
  ===================================================================
  RCS file: /export/home/cvs/apachen/htdocs/manual/misc/perf-tuning.html,v
  retrieving revision 1.1
  retrieving revision 1.2
  diff -u -r1.1 -r1.2
  --- perf-tuning.html	1997/09/30 23:24:30	1.1
  +++ perf-tuning.html	1997/10/24 09:39:17	1.2
  @@ -690,16 +690,23 @@
   
   On some architectures it's slower to <code>mmap</code> small
   files than it is to simply <code>read</code> them.  The define
  -<code>MMAP_THRESHOLD</code> can be set to the minimum size required before
  -using <code>mmap</code>.  By default it's set to 0 (except on SunOS4
  -where experimentation has shown 8192 to be a better value).  Using a
  -tool such as
  -<a href="http://reality.sgi.com/lm_engr/lmbench/lmbench.html">lmbench</a>
  -you can determine the optimal setting for your
  -environment.  It may even be the case that <code>mmap</code> isn't used
  -on your architecture, if so then defining <code>USE_MMAP_FILES</code>
  -might work (if it works then report back to us).
  +<code>MMAP_THRESHOLD</code> can be set to the minimum
  +size required before using <code>mmap</code>.  By default
  +it's set to 0 (except on SunOS4 where experimentation has
  +shown 8192 to be a better value).  Using a tool such as <a
  +href="http://reality.sgi.com/lm_engr/lmbench/lmbench.html">lmbench</a> you
  +can determine the optimal setting for your environment.
  +
  +<p>You may also wish to experiment with <code>MMAP_SEGMENT_SIZE</code>
  +(default 32768) which determines the maximum number of bytes that
  +will be written at a time from mmap()d files.  Apache only resets the
  +client's <code>Timeout</code> in between write()s.  So setting this
  +large may lock out low bandwidth clients unless you also increase the
  +<code>Timeout</code>.
   
  +<p>It may even be the case that <code>mmap</code> isn't
  +used on your architecture, if so then defining <code>USE_MMAP_FILES</code>
  +might work (if it works then report back to us).
   
   <p>Apache does its best to avoid copying bytes around in memory.  The
   first write of any request typically is turned into a <code>writev</code>
  
  
  

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