Hi all, The nice and clean option would be to use add an architecturally visible performance counter read from the DVFS governor (in software).
The hackish option is to change the clock speed behind the back of the OS, by having the DVFSHandler object change the clocks based on e.g. a probe point or similar. Andreas From: Nimish Girdhar <nimi...@tamu.edu<mailto:nimi...@tamu.edu>> Reply-To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Date: Wednesday, 15 April 2015 20:04 To: gem5 users mailing list <gem5-users@gem5.org<mailto:gem5-users@gem5.org>> Subject: Re: [gem5-users] DVFS with self defined policies on gem5 Okay.....Actually I am making the decision of what frequency which core has to run, inside the cpu... So I guess I have to somehow communicate this to the dvfs handler which doesn't look so clean.... Is there any other way around or hack anybody has done?? On Apr 15, 2015 10:14 AM, "Yahia Benmoussa" <yahia.benmou...@gmail.com<mailto:yahia.benmou...@gmail.com>> wrote: Hello, Setting the required frequency in /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed should not be in gem5 sources files. It can be done in a program (written in C, shell script or any other language) and running under Linux in FS mode. Regards Yahia 2015-04-15 16:55 GMT+02:00 Nimish Girdhar <nimi...@tamu.edu<mailto:nimi...@tamu.edu>>: Thanks Yahia for sharing that. Can you explain a bit more as I don't have much experience with that. Let's say I have some algo to decide the cpu freq in gem5 SRC/CPU/O3/commit_impl.hh... How can I set the file you mentioned to that freq from here?? Thanks, On Apr 15, 2015 2:53 AM, "Yahia Benmoussa" <yahia.benmou...@gmail.com<mailto:yahia.benmou...@gmail.com>> wrote: Hello, You have to enable userspace governor in your kernel then you can scale the CPU frequency by setting /sys/devices/system/cpu/cpu*/cpufreq/scaling_setspeed file. It should work. Regards. Yahia 2015-04-15 4:00 GMT+02:00 Nimish Girdhar <nimi...@tamu.edu<mailto:nimi...@tamu.edu>>: Hello all, I am working on a project where I have to use DVFS to change the frequency of cores based on my evaluation of some counters that I inserted in the gem5 o3 cpu src code. I followed the guidelines given on http://www.m5sim.org/Running_gem5#Experimenting_with_DVFS . But with these steps, the kernel will be the one who decides the performance levels of the cores at different point of time. But in my case I want to decide the levels based on some counters as mentioned above. Has anybody tried anything similar to that? I want to know how can I access and update the dvfs handler registers from within the cpu src code. Any help will be appreciated. Thanks, -- Warm regards Nimish Girdhar Department of Electrical and Computer Engineering Texas A&M University _______________________________________________ gem5-users mailing list gem5-users@gem5.org<mailto:gem5-users@gem5.org> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users _______________________________________________ gem5-users mailing list gem5-users@gem5.org<mailto:gem5-users@gem5.org> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users _______________________________________________ gem5-users mailing list gem5-users@gem5.org<mailto:gem5-users@gem5.org> http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users _______________________________________________ gem5-users mailing list gem5-users@gem5.org<mailto: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
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