httpd-cvs mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From bri...@apache.org
Subject cvs commit: httpd-2.0/docs/manual/misc perf-tuning.xml perf-tuning.html.en
Date Fri, 03 Jan 2003 23:12:56 GMT
brianp      2003/01/03 15:12:56

  Modified:    docs/manual/misc perf-tuning.xml perf-tuning.html.en
  Log:
  added some documentation about MPM selection and atomic operations
  
  Revision  Changes    Path
  1.5       +94 -0     httpd-2.0/docs/manual/misc/perf-tuning.xml
  
  Index: perf-tuning.xml
  ===================================================================
  RCS file: /home/cvs/httpd-2.0/docs/manual/misc/perf-tuning.xml,v
  retrieving revision 1.4
  retrieving revision 1.5
  diff -u -r1.4 -r1.5
  --- perf-tuning.xml	22 Dec 2002 20:14:45 -0000	1.4
  +++ perf-tuning.xml	3 Jan 2003 23:12:56 -0000	1.5
  @@ -404,6 +404,100 @@
   
       <section>
   
  +      <title>Choosing an MPM</title>
  +
  +      <p>Apache 2.x supports pluggable concurrency models, called
  +      <a href="../mpm.html">Multi-Processing Modules</a> (MPMs).
  +      When building Apache, you must choose an MPM to use.  There
  +      are platform-specific MPMs for some platforms:
  +      <module>beos</module>, <module>mpm_netware</module>,
  +      <module>mpmt_os2</module>, and <module>mpm_winnt</module>.
 For
  +      general Unix-type systems, there are several MPMs from which
  +      to choose.  The choice of MPM can affect the speed and scalability
  +      of the httpd:</p>
  +
  +      <ul>
  +
  +        <li>The <module>worker</module> MPM uses multiple child
  +        processes with many threads each.  Each thread handles
  +        one connection at a time.  Worker generally is a good
  +        choice for high-traffic servers because it has a smaller
  +        memory footprint than the prefork MPM.</li>
  +
  +        <li>The <module>prefork</module> MPM uses multiple child
  +        processes with one thread each.  Each process handles
  +        one connection at a time.  On many systems, prefork is
  +        comparable in speed to worker, but it uses more memory.
  +        Prefork's threadless design has advantages over worker
  +        in some situations: it can be used with non-thread-safe
  +        third-party modules, and it is easier to debug on platforms
  +        with poor thread debugging support.</li>
  +
  +      </ul>
  +
  +      <p>For more information on these and other MPMs, please
  +      see the MPM <a href="../mpm.html">documentation</a>.</p>
  +
  +    </section>
  +
  +    <section>
  +
  +      <title>Atomic Operations</title>
  +
  +      <p>Some modules, such as <module>mod_cache</module> and
  +      recent development builds of the worker MPM, use APR's
  +      atomic API.  This API provides atomic operations that can
  +      be used for lightweight thread synchronization.</p>
  +
  +      <p>By default, APR implements these operations using the
  +      most efficient mechanism available on each target
  +      OS/CPU platform.  Many modern CPUs, for example, have
  +      an instruction that does an atomic compare-and-swap (CAS)
  +      operation in hardware.  On some platforms, however, APR
  +      defaults to a slower, mutex-based implementation of the
  +      atomic API in order to ensure compatibility with older
  +      CPU models that lack such instructions.  If you are
  +      building Apache for one of these platforms, and you plan
  +      to run only on newer CPUs, you can select a faster atomic
  +      implementation at build time by configuring Apache with
  +      the <code>--enable-nonportable-atomics</code> option:</p>
  +
  +      <example>
  +        ./buildconf<br />
  +        ./configure --with-mpm=worker --enable-nonportable-atomics=yes
  +      </example>
  +
  +      <p>The <code>--enable-nonportable-atomics</code> option is
  +      relevant for the following platforms:</p>
  +
  +      <ul>
  +
  +        <li>Solaris on SPARC<br />
  +            By default, APR uses mutex-based atomics on Solaris/SPARC.
  +            If you configure with <code>--enable-nonportable-atomics</code>,
  +            however, APR generates code that uses a SPARC v8plus opcode for
  +            fast hardware compare-and-swap.  If you configure Apache with
  +            this option, the atomic operations will be more efficient
  +            (allowing for lower CPU utilization and higher concurrency),
  +            but the resulting executable will run only on UltraSPARC
  +            chips.
  +        </li>
  +
  +        <li>Linux on x86<br />
  +            By default, APR uses mutex-based atomics on Linux.  If you
  +            configure with <code>--enable-nonportable-atomics</code>,
  +            however, APR generates code that uses a 486 opcode for fast
  +            hardware compare-and-swap.  This will result in more efficient
  +            atomic operations, but the resulting executable will run only
  +            on 486 and later chips (and not on 386).
  +        </li>
  +
  +      </ul>
  +
  +    </section>
  +
  +    <section>
  +
         <title>mod_status and ExtendedStatus On</title>
   
         <p>If you include <module>mod_status</module> and you also set
  
  
  
  1.7       +94 -0     httpd-2.0/docs/manual/misc/perf-tuning.html.en
  
  Index: perf-tuning.html.en
  ===================================================================
  RCS file: /home/cvs/httpd-2.0/docs/manual/misc/perf-tuning.html.en,v
  retrieving revision 1.6
  retrieving revision 1.7
  diff -u -r1.6 -r1.7
  --- perf-tuning.html.en	22 Dec 2002 20:14:45 -0000	1.6
  +++ perf-tuning.html.en	3 Jan 2003 23:12:56 -0000	1.7
  @@ -386,6 +386,100 @@
   
       
   
  +    <h3>Choosing an MPM</h3>
  +
  +      
  +
  +      <p>Apache 2.x supports pluggable concurrency models, called
  +      <a href="../mpm.html">Multi-Processing Modules</a> (MPMs).
  +      When building Apache, you must choose an MPM to use.  There
  +      are platform-specific MPMs for some platforms:
  +      <code class="module"><a href="../mod/beos.html">beos</a></code>,
<code class="module"><a href="../mod/mpm_netware.html">mpm_netware</a></code>,
  +      <code class="module"><a href="../mod/mpmt_os2.html">mpmt_os2</a></code>,
and <code class="module"><a href="../mod/mpm_winnt.html">mpm_winnt</a></code>.
 For
  +      general Unix-type systems, there are several MPMs from which
  +      to choose.  The choice of MPM can affect the speed and scalability
  +      of the httpd:</p>
  +
  +      <ul>
  +
  +        <li>The <code class="module"><a href="../mod/worker.html">worker</a></code>
MPM uses multiple child
  +        processes with many threads each.  Each thread handles
  +        one connection at a time.  Worker generally is a good
  +        choice for high-traffic servers because it has a smaller
  +        memory footprint than the prefork MPM.</li>
  +
  +        <li>The <code class="module"><a href="../mod/prefork.html">prefork</a></code>
MPM uses multiple child
  +        processes with one thread each.  Each process handles
  +        one connection at a time.  On many systems, prefork is
  +        comparable in speed to worker, but it uses more memory.
  +        Prefork's threadless design has advantages over worker
  +        in some situations: it can be used with non-thread-safe
  +        third-party modules, and it is easier to debug on platforms
  +        with poor thread debugging support.</li>
  +
  +      </ul>
  +
  +      <p>For more information on these and other MPMs, please
  +      see the MPM <a href="../mpm.html">documentation</a>.</p>
  +
  +    
  +
  +    <h3>Atomic Operations</h3>
  +
  +      
  +
  +      <p>Some modules, such as <code class="module"><a href="../mod/mod_cache.html">mod_cache</a></code>
and
  +      recent development builds of the worker MPM, use APR's
  +      atomic API.  This API provides atomic operations that can
  +      be used for lightweight thread synchronization.</p>
  +
  +      <p>By default, APR implements these operations using the
  +      most efficient mechanism available on each target
  +      OS/CPU platform.  Many modern CPUs, for example, have
  +      an instruction that does an atomic compare-and-swap (CAS)
  +      operation in hardware.  On some platforms, however, APR
  +      defaults to a slower, mutex-based implementation of the
  +      atomic API in order to ensure compatibility with older
  +      CPU models that lack such instructions.  If you are
  +      building Apache for one of these platforms, and you plan
  +      to run only on newer CPUs, you can select a faster atomic
  +      implementation at build time by configuring Apache with
  +      the <code>--enable-nonportable-atomics</code> option:</p>
  +
  +      <div class="example"><p><code>
  +        ./buildconf<br />
  +        ./configure --with-mpm=worker --enable-nonportable-atomics=yes
  +      </code></p></div>
  +
  +      <p>The <code>--enable-nonportable-atomics</code> option is
  +      relevant for the following platforms:</p>
  +
  +      <ul>
  +
  +        <li>Solaris on SPARC<br />
  +            By default, APR uses mutex-based atomics on Solaris/SPARC.
  +            If you configure with <code>--enable-nonportable-atomics</code>,
  +            however, APR generates code that uses a SPARC v8plus opcode for
  +            fast hardware compare-and-swap.  If you configure Apache with
  +            this option, the atomic operations will be more efficient
  +            (allowing for lower CPU utilization and higher concurrency),
  +            but the resulting executable will run only on UltraSPARC
  +            chips.
  +        </li>
  +
  +        <li>Linux on x86<br />
  +            By default, APR uses mutex-based atomics on Linux.  If you
  +            configure with <code>--enable-nonportable-atomics</code>,
  +            however, APR generates code that uses a 486 opcode for fast
  +            hardware compare-and-swap.  This will result in more efficient
  +            atomic operations, but the resulting executable will run only
  +            on 486 and later chips (and not on 386).
  +        </li>
  +
  +      </ul>
  +
  +    
  +
       <h3>mod_status and ExtendedStatus On</h3>
   
         
  
  
  

Mime
View raw message