Tushar, Thank you very much! I will try this first:)
Best, Jinzhu On Mon, Aug 6, 2012 at 7:16 PM, Tushar Krishna <[email protected]> wrote: > ** > Hi Jinzhu, > The crossbar topology in gem5 simply connects all controllers (cache and > directory) to one router/switch. > If two cores A and B send out a broadcast, the requirement is that all > nodes receive the broadcast in the same order. > The released version of garnet does not have broadcast support: every > broadcast is sent as multiple unicasts from the source Network Interface. > So it is possible that some cores receive A's unicasts before those B, and > vice versa, breaking ordering. > While you are testing out your protocol, I would suggest using the simple > network (don't add the --garnet-network option) which has the capability of > replicating messages. > I am not 100% sure if it'll solve this issue but might. > If you still get an ordering violation, you will need to go into the > network and see why messages from A and B get delivered in different orders > to cores. > > Once you are sure that the protocol works, then you can either edit the > simple network switch itself to model your design (but the simple network > has a fuzzy congestion model), or plug in garnet (if you want a more > detailed network model) and add broadcast support to it. > > - Tushar > > > > On 08/06/2012 05:00 PM, gem5 gem5 wrote: > > Hi Tushar, > > Thanks a lot! I used the command you gave to me and find out that the > total ordering of the protocol is violated. I used the Crossbar topology in > GEM5. I think it's a simplified version of HIERARCHICAL SWITCH in GEMS, so > it should provide total ordering(the root node is the serialization point). > Do I misunderstand something here? Can the protocol cause the violation if > it's not the topology? Thank you! > > Best, > Jinzhu > > On Fri, Aug 3, 2012 at 8:12 PM, Tushar Krishna <[email protected]>wrote: > >> Hi Jinzhu, >> The error is that your protocol found an invalid transition when in state >> "I". >> If you grep for "Invalid transition", you will see that this error >> message was most likely printed out from >> build/X86_SE/mem/protocol/L1Cache_Transitions.cc >> >> You can print out a protocol trace in such cases to understand what >> happened. >> ./build/X86_SE/gem5.opt --debug-flags=ProtocolTrace >> configs/example/ruby_random_test.py --num-cpus=4 --num-dirs=1 >> --topology=Crossbar --garnet-network=flexible >> >> Look at the requests/responses for that address and figure out what went >> wrong… >> >> cheers, >> Tushar >> >> >> On Jul 31, 2012, at 6:50 PM, gem5 gem5 wrote: >> >> > Hi all, >> > >> > I want to move the MOSI_SMP_bcast protocol from GEMS to GEM5. I >> modified the original MOSI_SMP_bcast_1level protocol to become >> MOSI_CMP_bcast_1level. However, when I ran it with ruby_random_test.py on >> Crossbar topology ( build/X86_SE/gem5.opt --debug-flags=Ruby >> configs/example/ruby_random_test.py --num-cpus=4 --num-dirs=1 >> --topology=Crossbar --garnet-network=flexible >> > ), I got an error like this: >> > >> > "fatal: Invalid transition >> > system.l1_cntrl3 time: 2835 addr: [0x14c0, line 0x14c0] event: Data >> state: I" >> > >> > Here are my questions; >> > >> > 1. GEMS uses a HIERARCHICAL_SWITCH to work as a logical bus to provide >> total ordering. As I understand it, the crossbar implemented in GEM5 is a >> simplified version of HIERARCHICAL_SWITCH. The root router is the >> serialization point and it should provide the total ordering for the >> broadcast protocol. I wonder if this is correct or not and if this error is >> due to lack of total ordering. >> > 2. The original MOSI_SMP_bcast_1level-cache.sm has a StoreBuffer >> inside, but it is no long supported in GEM5 , I wonder if this could be the >> problem. What else changes of SLICC in GEM5 could introduce this error? >> > 3. If none of those is the reason, I wonder what 's the right way to >> debug and fix this error. I don't have much experience with this.. >> > >> > Thanks a lot! >> > >> > Best, >> > >> > Jinzhu >> > >> > _______________________________________________ >> > gem5-users mailing list >> > [email protected] >> > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >> >> _______________________________________________ >> gem5-users mailing list >> [email protected] >> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >> > > > _______________________________________________ > gem5-users mailing > [email protected]http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users > > > _______________________________________________ > gem5-users mailing list > [email protected] > http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users >
_______________________________________________ gem5-users mailing list [email protected] http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
