8 Replies Latest reply on Aug 17, 2011 3:36 PM by tedk

    MCPC-Core communication

    darence

      I am not sure I fully understand how the communication between the MCPC and a core on the SCC works. What happens internally when I, for instance, ping a core? Does the packet reach the core via the NoC? If yes, could you please provide more details (what router is connected to the system bus etc)?

       

      Thank you!

        • 1. Re: MCPC-Core communication
          tedk

          When you are running 1.4.1.3 (the latest sccKit), sccKit commands go across the PCIe bus using the crbif driver. Programs on the cores communciate with the MCPC over the eMAC interface. Ping goes across the eMAC interface. sccPerf goes over PCIe.

          • 2. Re: MCPC-Core communication
            darence

            Ted,

             

            Thanks for the prompt response. I just need some more clarification. Is each SCC core connected to the eMAC interface and the PCIe directly? Actually, I would like to know whether the underlying NoC on the SCC is used for routing the traffic that goes to/from the MCPC or not. And if yes, when exactly?

             

            Thank you.

            • 3. Re: MCPC-Core communication
              tedk

              In general ... bits from a core are routed (x-y routing) to the SIF (system interface) at x=2,y=0 in the SCC mesh. The FPGA connects to that SIF and decides whether to send the bits over the PCIe or eMAC. Is this what you're looking for?

              • 4. Re: MCPC-Core communication
                wbrozas

                Is 1.4.1.3  officially out? Because I tried the patch and I am still unable to ssh rck00 -l root; ping rckX (Where X is some number other than 00)

                 

                Or does 1.4.1.3 not fix that bug?

                • 5. Re: MCPC-Core communication
                  tedk

                  Yes, but the only difference between 1.4.1.2 and 1.4.1.3 is that sccProductiontest works (which is a good thing).

                  ssh between cores does not work unless you modify the /etc/hosts file on the MCPC  as shown in Bug 294.

                   

                  http://marcbug.scc-dc.com/bugzilla3/show_bug.cgi?id=294

                   

                  mpdboot won't work but the workaround described in the bug does. mpdboot has a timing issue; it's not a problem with mpdboot.

                   

                  We haven't yet made a 1.4.1.3 tar but the patch3 tar is on our SVN. And you can download that and untar it in /opt/sccKit.

                  http://marcbug.scc-dc.com/svn/repository/tarballs/

                   

                  What we do with our machines to keep track of what is installed is to keep the tar in /opt/sccKit. The splash screen for sccKit still says 1.4.1 even after you apply patch 3 which we call 1.4.1.3. Modifying the splash screen is not difficult, but no one has gotten to it.

                  • 6. Re: MCPC-Core communication
                    wbrozas

                    I still cannot ping other cores with new patch. I read the bug report and turned off bind9

                     

                    Status: The following cores can be reached with ping (booted): All cores!

                    $ ssh 192.168.2.1 -l root
                    # ping 192.168.2.2
                    PING 192.168.2.2 (192.168.2.2): 56 data bytes
                    ^C
                    --- 192.168.2.2 ping statistics ---
                    23 packets transmitted, 0 packets received, 100% packet loss

                     

                     

                    Note: I installed the patch August 17 on top of 1.4.1.2

                     

                    $ tar -tf sccKit_1.4.1_patch3.tar.bz2
                    tar: Record size = 8 blocks
                    current/bin/sccProductiontest
                    current/resources/copycat_0_0.32.obj
                    current/resources/copycat.dat
                    current/resources/GOLDEN_REFERENCE.log
                    current/resources/linux.obj
                    current/resources/patch.dat
                    current/resources/premerge_image_0_0.32.obj
                    current/resources/startclk.dat
                    current/resources/status.rcc
                    current/resources/stopclk.dat
                    current/resources/stream_16KB_L1_x586
                    current/resources/stream_200KB_L2_n1000_x586

                     

                    $ ls -l /opt/sccKit/current/bin/
                    total 8980
                    -rwxr-xr-x 1 root root   12977  2011-06-28 09:03 bin2obj
                    -rwxr-xr-x 1 root root  793445 2011-06-28 09:03 sccBmc
                    -rwxr-xr-x 1 root root  900163 2011-07-04 09:22 sccBoot
                    -rwxr-xr-x 1 root root     5011 2011-06-28 09:03 sccBootlogs
                    -rwxr-xr-x 1 root root    1543 2011-06-28 09:03 sccCmdline
                    -rwxr-xr-x 1 root root  986356 2011-07-04 09:22 sccDisplay
                    -rwxr-xr-x 1 root root  754018 2011-06-28 09:03 sccDump
                    -rwxr-xr-x 1 root root 1620294 2011-06-28 09:03 sccGui
                    -rwxr-xr-x 1 root root  797428 2011-07-04 09:22 sccKonsole
                    -rwxr-xr-x 1 root root   31899 2011-07-04 08:44 sccMerge
                    -rwxr-xr-x 1 root root  828949 2011-06-28 09:03 sccPerf
                    -rwxr-xr-x 1 root root    5575 2011-07-01 08:58 sccPowercycle
                    -rwxr-xr-x 1 root root    1369 2011-08-17 14:56 sccProductiontest
                    -rwxr-xr-x 1 root root  776125 2011-06-28 09:03 sccReset
                    -rwxr-xr-x 1 root root  820071 2011-06-28 09:03 sccTcpServer
                    -rwxr-xr-x 1 root root  825151 2011-06-28 09:03 sccWrite

                     

                    $ ls -l /opt/sccKit/current/resources/
                    total 235232
                    -r-xr-xr-x 1 root root   1245219 2011-08-17 14:57 copycat_0_0.32.obj
                    -r-xr-xr-x 1 root root    110423 2011-08-17 14:57 copycat.dat
                    -rwxr-x--- 1 root root       314 2011-08-17 14:57 GOLDEN_REFERENCE.log
                    -r-xr-xr-x 1 root root 119110683 2011-08-17 14:57 linux.obj
                    -r-xr-xr-x 1 root root      3312 2011-08-17 14:57 patch.dat
                    -r-xr-xr-x 1 root root 119110710 2011-08-17 14:57 premerge_image_0_0.32.obj
                    -rwxr-xr-x 1 root root       912 2011-08-17 14:57 startclk.dat
                    -rwxr-xr-x 1 root root         8 2011-08-17 14:57 status.rcc
                    -rwxr-xr-x 1 root root       912 2011-08-17 14:57 stopclk.dat
                    -rwxr-x--- 1 root root    632906 2011-08-17 14:57 stream_16KB_L1_x586
                    -rwxr-x--- 1 root root    634961 2011-08-17 14:57 stream_200KB_L2_n1000_x586
                    $

                    • 7. Re: MCPC-Core communication
                      tedk

                      Did you modify the /etc/hosts file on the MCPC as described in the bug?

                      • 8. Re: MCPC-Core communication
                        wbrozas

                        The DNS shouldn't matter. I see what you did. Yah it works I didn't realize the cores were going to communicate to each other over a different interface.

                         

                        I was expecting to ping 192.168.2.2 but I see its 192.168.0.2