result in *fat* simulation hindering debugging.
- It was really boring to write 25,000 entries in the deployment
file, so I wrote a little script
- <tt>examples/gras/tokenS/make_deployment.pl</tt>, which you may
+ <tt>examples/gras/mutual_exclusion/simple_token/make_deployment.pl</tt>, which you may
want to adapt to your case. You could also think about hijacking
the SURFXML parser (have look at \ref faq_flexml_bypassing).
- The deployment file became quite big, so I had to do what is in
user don't get into trouble about this. You want to tune this
size to increse the number of processes. This is the
<tt>STACK_SIZE</tt> define in
- <tt>src/xbt/context_private.h</tt>, which is 128kb by default.
+ <tt>src/xbt/xbt_context_sysv.c</tt>, which is 128kb by default.
Reduce this as much as you can, but be warned that if this value
is too low, you'll get a segfault. The token ring example, which
- is quite simple, runs with 40kb stacks.
+ is quite simple, runs with 40kb stacks.
+ - You may tweak the logs to reduce the stack size further. When
+ logging something, we try to build the string to display in a
+ char array on the stack. The size of this array is constant (and
+ equal to XBT_LOG_BUFF_SIZE, defined in include/xbt/log/h). If the
+ string is too large to fit this buffer, we move to a dynamically
+ sized buffer. In which case, we have to traverse one time the log
+ event arguments to compute the size we need for the buffer,
+ malloc it, and traverse the argument list again to do the actual
+ job.\n
+ The idea here is to move XBT_LOG_BUFF_SIZE to 1, forcing the logs
+ to use a dynamic array each time. This allows us to lower further
+ the stack size at the price of some performance loss...\n
+ This allowed me to run the reduce the stack size to ... 4k. Ie,
+ on my 1Gb laptop, I can run more than 250,000 processes!
\subsubsection faq_MIA_batch_scheduler Is there a native support for batch schedulers in SimGrid?
\subsubsection faq_trouble_errors_big_fat_warning I'm told that my XML files are too old.
-We have decided to change the units in SimGrid. Now we use Bytes, Flops and
-seconds instead of MBytes, MFlops and seconds... Units should be updated
-accordingly and the version of platform_description should be set to a
-valuer greater than 1:
+The format of the XML platform description files is sometimes
+improved. For example, we decided to change the units used in SimGrid
+from MBytes, MFlops and seconds to Bytes, Flops and seconds to ease
+people exchanging small messages. We also reworked the route
+descriptions to allow more compact descriptions.
+
+That is why the XML files are versionned using the 'version' attribute
+of the root tag. Currently, it should read:
\verbatim
- <platform_description version="1">
+ <platform version="2">
\endverbatim
-You should try to use the surfxml_update.pl script that can be found
-<a href="https://gforge.inria.fr/plugins/scmsvn/viewcvs.php/contrib/trunk/platform_generation/?rev=4721&root=simgrid"">here</a>.
+
+If your files are too old, you can use the simgrid_update_xml.pl
+script which can be found in the tools directory of the archive.
\subsection faq_trouble_valgrind Valgrind-related issues
