[gem5-users] Re: System() and RubySystem()
Hi Javed, Please, see my comments inline. Best, Gabriel Javed Osmany wrote: > Hello > > Trying to understand the following: > > So in example config scripts I see the following: > > system = System() // Is this then instantiating the default overall > system ?? This is pretty much it, yes. > > Now, I understand that there are two types of memory system, namely classic > and Ruby. Yes. > > And then if "-ruby" is specified on the command line, the script Ruby.py is > called. > Within Ruby.py, the function creat_system() is called and in Ruby.py (lines > 193 - 194), we > have the code > >system.ruby = Ruby.System() // Is this then instantiating the Ruby > memory system > within the overall System() ?? Here it gets a bit more technical but you are right. Let me detail a little bit more what is going on. BTW, Not sure which version of gem5 you have but I don't have a dot between Ruby and System and I believe that you should not have one either. system, which is an instance of the System python class, is what is called a SimObject. The SimObject python class, which System inherits from, gives special capabilities. The most important one is to be able to build a SimObject tree by asigning SimObjects to other SimObjetcs attributes. For instance, with A, B, C and D being SimObject instances, one can write: A.b = B; B.c = c; A.d = d // Builds the SimObject tree [A->B->C ; A->D] The SimObject tree that you have before calling m5.instantiate will define the order in which the C++ version of each SimObject will be constructed. You basically go from the leafs to the root of the SimObject tree so that all parameters are valid in each C++ SimObject constructor. Then, the init method of each C++ SimObject is called in a non-specified order in order to perform extra operations that cannot take place in the constructor. In the present case, an instance of the SimObject "RubySystem" is being assigned to the ruby attribute of system (which also is a SimObject). system initially has no ruby attribute but because we are assigning a SimObject, magic happens behind the scene and a new attribute "ruby" is dynamically added. Notice that you could use any attribute name instead of ruby. In a nutshell, yes, our new RubySystem is now "physically" part of the overall System. >ruby= system.ruby // This is then just an alias ?? Yes, this is a local alias: system.ruby could be used instead of ruby in the rest of the function. > > > Thanks in advance. > J.Osmany ___ gem5-users mailing list -- gem5-users@gem5.org To unsubscribe send an email to gem5-users-le...@gem5.org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
[gem5-users] Re: System() and RubySystem()
Many thanks for the clarification Giacomo. Best regards JO -Original Message- From: Giacomo Travaglini [mailto:giacomo.travagl...@arm.com] Sent: 16 June 2021 11:36 To: gem5 users mailing list Cc: Javed Osmany Subject: RE: System() and RubySystem() Hi Javed, You are correct in your assumptions. I believe the confusion arises from the overuse of the "System" keyword. As a summary, The System class (defined in src/sim/system.hh) is the child of the Root node and encompasses most of the simulated models (cpu, memory subsystem, devices, etc). The RubySystem is a child of the System class (system.ruby = RubySystem() adds the RubySystem to the SimObject hierarchy under the system node). In other words, the RubySystem is a subsystem, whose only purpose is to parent ruby memory models. It is not a replacement for the System class nor a different implementation Kind regards Giacomo > -Original Message- > From: Javed Osmany via gem5-users > Sent: 16 June 2021 11:17 > To: gem5 users mailing list > Cc: Javed Osmany > Subject: [gem5-users] FW: System() and RubySystem() > > Hello > > > > Wondering if any help to clear up the issues listed in my previous email? > > > > Tks > > JO > > > > From: Javed Osmany > Sent: 14 June 2021 14:18 > To: gem5 users mailing list > Cc: Javed Osmany > Subject: System() and RubySystem() > > > > Hello > > > > Trying to understand the following: > > > > So in example config scripts I see the following: > > > > system = System() // Is this then instantiating the default > overall system ?? > > > > Now, I understand that there are two types of memory system, namely > classic and Ruby. > > > > And then if "-ruby" is specified on the command line, the script > Ruby.py is called. > > Within Ruby.py, the function creat_system() is called and in Ruby.py > (lines > 193 - 194), we have the code > > > >system.ruby = Ruby.System() // Is this then instantiating the > Ruby memory system within the overall System() ?? > >ruby= system.ruby // This is then just an alias ?? > > > > > > Thanks in advance. > > J.Osmany IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. ___ gem5-users mailing list -- gem5-users@gem5.org To unsubscribe send an email to gem5-users-le...@gem5.org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
[gem5-users] Re: System() and RubySystem()
Hi Javed, You are correct in your assumptions. I believe the confusion arises from the overuse of the "System" keyword. As a summary, The System class (defined in src/sim/system.hh) is the child of the Root node and encompasses most of the simulated models (cpu, memory subsystem, devices, etc). The RubySystem is a child of the System class (system.ruby = RubySystem() adds the RubySystem to the SimObject hierarchy under the system node). In other words, the RubySystem is a subsystem, whose only purpose is to parent ruby memory models. It is not a replacement for the System class nor a different implementation Kind regards Giacomo > -Original Message- > From: Javed Osmany via gem5-users > Sent: 16 June 2021 11:17 > To: gem5 users mailing list > Cc: Javed Osmany > Subject: [gem5-users] FW: System() and RubySystem() > > Hello > > > > Wondering if any help to clear up the issues listed in my previous email? > > > > Tks > > JO > > > > From: Javed Osmany > Sent: 14 June 2021 14:18 > To: gem5 users mailing list > Cc: Javed Osmany > Subject: System() and RubySystem() > > > > Hello > > > > Trying to understand the following: > > > > So in example config scripts I see the following: > > > > system = System() // Is this then instantiating the default overall > system ?? > > > > Now, I understand that there are two types of memory system, namely > classic and Ruby. > > > > And then if "-ruby" is specified on the command line, the script Ruby.py is > called. > > Within Ruby.py, the function creat_system() is called and in Ruby.py (lines > 193 - 194), we have the code > > > >system.ruby = Ruby.System() // Is this then instantiating the Ruby > memory system within the overall System() ?? > >ruby= system.ruby // This is then just an alias ?? > > > > > > Thanks in advance. > > J.Osmany IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you. ___ gem5-users mailing list -- gem5-users@gem5.org To unsubscribe send an email to gem5-users-le...@gem5.org %(web_page_url)slistinfo%(cgiext)s/%(_internal_name)s
