svn commit: r759957 - /httpd/httpd/trunk/docs/manual/mod/mpm_common.xml

[co...@apache.org]

Author: covener
Date: Mon Mar 30 13:26:02 2009
New Revision: 759957

URL: http://svn.apache.org/viewvc?rev=759957&view=rev
Log:
Clarify when CoreDumpDirectory can be moot based on OS configuration, and 
mention SIGQUIT/3 not being processed by the signal handler.  

SIGQUIT may unfortunately be a go-to signal for java users.


Modified:
    httpd/httpd/trunk/docs/manual/mod/mpm_common.xml

Modified: httpd/httpd/trunk/docs/manual/mod/mpm_common.xml
URL: http://svn.apache.org/viewvc/httpd/httpd/trunk/docs/manual/mod/mpm_common.xml?rev=759957&r1=759956&r2=759957&view=diff
==============================================================================
--- httpd/httpd/trunk/docs/manual/mod/mpm_common.xml (original)
+++ httpd/httpd/trunk/docs/manual/mod/mpm_common.xml Mon Mar 30 13:26:02 2009
@@ -129,13 +129,17 @@
 
 <usage>
     <p>This controls the directory to which Apache attempts to
-    switch before dumping core. The default is in the
-    <directive module="core">ServerRoot</directive> directory, however
-    since this should not be writable by the user the server runs
-    as, core dumps won't normally get written. If you want a core
-    dump for debugging, you can use this directive to place it in a
-    different location.</p>
-
+    switch before dumping core. If your operating system is configured to
+    create core files in the crashing processes working directory, 
+    <directive>CoreDumpDirectory</directive> is necessary to change working
+    directory from the default <directive module="core">ServerRoot</directive> 
+    directory, which should not be writable by the user the server runs as.</p>
+
+    <p>If you want a core dump for debugging, you can use this directive to 
+    place it in a different location. This directive has no effect if your
+    operating system is not configured to write core files to the crashing 
+    processes working directory.</p>
+    
     <note><title>Core Dumps on Linux</title>
       <p>If Apache starts as root and switches to another user, the
       Linux kernel <em>disables</em> core dumps even if the directory is
@@ -143,6 +147,17 @@
       on Linux 2.4 and beyond, but only if you explicitly configure a <directive
       >CoreDumpDirectory</directive>.</p>
     </note>
+
+    <note><title>Specific signals</title>
+      <p><directive>CoreDumpDirectory</directive> processing only occurs for 
+      a select set of fatal signals: SIGFPE, SIGILL, SIGABORT, 
+      SIGSEGV, and SIGBUS.</p>
+      <p>On some operating systems, SIGQUIT also results in a core dump but
+      does not go through <directive>CoreDumpDirectory</directive> or
+      <directive>EnableExceptionHook</directive> processing, so the core
+      location is dictated entirely by the operating system.</p>
+    </note>
+
 </usage>
 </directivesynopsis>