Re: [gem5-users] simObject clocks and global simulation clock
Andreas, I think my question is still not clear. I'm working on GEM5 to provide my company design team a tool that would simulate their models. Our mainly working is interconnection model. I am trying to model a given architecture with some router models. By extrenal object I mean: When I give this tool with the modeled architecture to the design team, the goal is that they can just parametrize system objects without knowing how the gem5 kernel works. When they come with an object with a clock period less than the tick value I have prefixed, should they modify this tick value to suite their object clocks? Sorry for these questions, I am wondering if the concept of adapting it to the system exists in gem5 because the user of the simulator can not always be the developer of the simulated model. Best, Anny. ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Hi Andreas, I have one more question. In ticks.py, there is a variable tps_fixed initialized to false. This value is set to true in fixGlobalFrequency function. Is there a case where this value is not changed to true? Suppose that tick value is fixed to 10 ps, when an external object that comes from another library has its clock period set to 1 ps, to not miss events of this object, we should change the value tick to 1 ps, is this done by the user or there is a function which automatically compute the suitable tick value ? Best, Anny, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Hi Anny, I do not understand the case you are describing. What “external” object are you referring to? Andreas On 22/12/2014 16:43, Anny via gem5-users gem5-users@gem5.org wrote: Hi Andreas, I have one more question. In ticks.py, there is a variable tps_fixed initialized to false. This value is set to true in fixGlobalFrequency function. Is there a case where this value is not changed to true? Suppose that tick value is fixed to 10 ps, when an external object that comes from another library has its clock period set to 1 ps, to not miss events of this object, we should change the value tick to 1 ps, is this done by the user or there is a function which automatically compute the suitable tick value ? Best, Anny, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- 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. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2548782 ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
I mean asynchronous object. The main question is : Is there a funtion that computes the suitable tick value for the objects in the system? Anny, Best, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Hi Anny, I still do not understand what you are referring to. I think you have to try and up-level your question a bit. As my original response stated, the global time is discretised into Ticks, and all objects will thus convert any cycles etc to a value on this discretised timescale, just like any other discrete-event simulation kernel out there. gem5 is not different in this aspect. If you want to set the Tick resolution to a very large value, go ahead, and if you feel 1 ps is too large already then set it to 1 fs. There is no magic here. Andreas On 22/12/2014 17:00, Anny via gem5-users gem5-users@gem5.org wrote: I mean asynchronous object. The main question is : Is there a funtion that computes the suitable tick value for the objects in the system? Anny, Best, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- 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. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2548782 ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Do you mean that the tick value does not change over the simulation time? Once it is fixed, its value never changes. Am I right? So the tps_value is always set to true and never to false. Anny, Andreas Hansson via gem5-users gem5-users at gem5.org writes: ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
All objects must have a clock? Anny, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
No. There is a global time, and we discretise it into units of Ticks, by default ps. You can set if to any arbitrarily fine-grained quanta. Andreas On 19/12/2014 11:48, Anny via gem5-users gem5-users@gem5.org wrote: All objects must have a clock? Anny, ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users -- 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. ARM Limited, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2557590 ARM Holdings plc, Registered office 110 Fulbourn Road, Cambridge CB1 9NJ, Registered in England Wales, Company No: 2548782 ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Ok thank you Andreas for your reply, Best, Anny ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
[gem5-users] simObject clocks and global simulation clock
Hi all, I have a question about clocks on gem5. In gem5, it seems that there is a global simulation clock and every simObject has a clock domain. The eventq is sorted in time. When two objects with two different clocks schedule two events on eventq, how the order is determined since the two objects have different clocks? Are all objects synchronious? it seems that everything in the system is based of one clock (global simulation clock)? It is binding. Best, Anny. ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] simObject clocks and global simulation clock
Ticks is the basic unit of time in gem5. gem5 uses this for synchronization. Every system cycle is made up of n number of ticks ticks. For a system unit with frequency = 2 GHZ, one cycle = 500 ticks On Tue, Dec 16, 2014 at 7:04 PM, Anny via gem5-users gem5-users@gem5.org wrote: Hi all, I have a question about clocks on gem5. In gem5, it seems that there is a global simulation clock and every simObject has a clock domain. The eventq is sorted in time. When two objects with two different clocks schedule two events on eventq, how the order is determined since the two objects have different clocks? Are all objects synchronious? it seems that everything in the system is based of one clock (global simulation clock)? It is binding. Best, Anny. ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
