Notes for first discussion

Outline

1. Administrative stuff.
2. How to log in, compile and run "hello world".
3. Fast 2x2 Matrix Multiply

How to log in, compile and run "hello world".

1. Machine names rodin, moore
   add to PATH /usr/cm5/bin:/usr/cm5/local/bin
   add to MANPATH /usr/cm5/man:/usr/cm5/local/man
2. Basic Architecture (Jim will cover this in class, also see http://www.cs.berkeley.edu/~demmel/cs267/cm5docs/tech-summary).
3. CM5 executables:
   consists of a host program to run on the
   host, and a node program.
   Sometimes the host program is invisible to you (split-C, cm-fortran). Each program is a separate normal object file, each with it's own 'main()' routine.
4. Programs:

         cmps: display the status of current CM processes
               Useful to tell how loaded the machine is.
               *'d pid tells which one is currently running.
         djm: distributed job manager
            Method to submit batch jobs. Does a nice
            job with redireting I/O appropriately.
              -help to get options
            Main interface 'job'
            Useful Commands:
                status  Show the status of all running jobs   
                submit  Submit a background job
                run     run an interactive job
                signal  send a signal to a running job
                kill    kill a running job
         cmjoin: produce a CM5 executable from
            two standard executable files.
         cmld: CM5 link editor for object files.
             This is what you use in a Makefile.
   Things to be aware of:
        ts-daemon: Liaison process between host and nodes
          Sometimes goes down.
        Mail to fraser@cs if the thing goes down. 
        
   Compiling and linking:
        - host/node programs
        - sometimes it's hidden from you.
        - Standard .o files.
        - Use an already working makefile (take the one we supply)
   
   hello-host.c
   
   
   #include <stdio.h>
   #include <cm/cmmd.h>
   
   
   main()
   {
     CMMD_enable();
     printf("Hello world from host.\n");
   }
   
   
   hello-node.c
   
   
   #include <stdio.h>
   #include <cm/cmmd.h>
   
   main()
   {
     int myaddress;
     CMMD_fset_io_mode(stdout, CMMD_independent);
     myaddress = CMMD_self_address();
     printf("Node %d: Hello world\n",myaddress);
     CMMD_enable_host();
   }
   
   
   Makefile
   
   TARGET          = hello
   HOST_SRCS       = hello-host.c
   HOST_OBJS       = $(HOST_SRCS:%.c=%.o)
   NODE_SRCS       = hello-node.c
   NODE_OBJS       = $(NODE_SRCS:%.c=%.o)
   INCDIRS         = /usr/cm5/include
   HOST_LIBDIRS    = /usr/cm5/lib
   NODE_LIBDIRS    = /usr/cm5/lib
   HOST_LIBS       =
   NODE_LIBS       =
   CC              = gcc
   
   %-host.o: %-host.c
           $(CC) -DCP_CODE $(CFLAGS) $(INCDIRS:%=-I%) -c $<
   %-node.o: %-node.c
           $(CC) $(CFLAGS) $(INCDIRS:%=-I%) -c $<
   $(TARGET):      $(NODE_OBJS) $(HOST_OBJS)
           /usr/cm5/bin/cmmd-ld \
           -comp $(CC) -o $(TARGET) \
           -node $(NODE_OBJS) $(NODE_LIBDIRS:%=-L%) $(NODE_LIBS:%=-l%) \
           -host $(HOST_OBJS) $(HOST_LIBDIRS:%=-L%) $(HOST_LIBS:%=-l%)
   clean:
           rm -f $(TARGET) $(NODE_OBJS) $(HOST_OBJS) *~ .make.state .nse_depinfo
   
   
   
   

2x2 Matrix Multiply

Solution:

#define mul_mfmf_mf2x2(c11,c12,c21,c22,A,Asep,B,Bsep)
{
   const float *bp,*ap; 
   float b1,b2;
   float a;

   bp = B;
   b1 = bp[0]; b2 = bp[1]; 
   bp += Bsep; 

   ap = A;
   a = ap[0]; ap += Asep;

   c11 += a*b1; /* c11 += a11*b11 */
   c12 += a*b2; /* c12 += a11*b12 */

   a = ap[0]; ap = &A[1];

   c21 += a*b1; /* c21 += a21*b11 */
   c22 += a*b2; /* c22 += a21*b12 */

   b1 = bp[0]; b2 = bp[1];
   a = ap[0]; ap += Asep;

   c11 += a*b1; /* c11 += a12*b21 */
   c12 += a*b2; /* c12 += a12*b22 */

   a = ap[0];

   c21 += a*b1; /* c21 += a22*b21 */
   c22 += a*b2; /* c22 += a22*b22 */
}