Hello Andreas, We are considering to use ArmKvmCPU. I have a couple of questions regarding its simulation methodology. From my understanding so far, KVM is a good way to speedup simulations by switching between virtual (faster) and simulated CPU. So, I am wondering if we can rely on all Gem5 stats that will be reported after the simulation? Will running an arm_detailed CPU and ArmKvmCPU result in similar stats? Also, does KVM CPU use dram controller from Gem5 to simulate memory or it uses host physical memory?
Thanks, -Rizwana On Mon, Aug 3, 2015 at 3:31 PM, Davesh Shingari <[email protected]> wrote: > Thanks a lot for clarification. > I didn't know about that. > ᐧ > > On Mon, Aug 3, 2015 at 9:47 AM, Guru Prasad <[email protected]> wrote: > >> Gem5 has a command line argument --dual. This starts up 2 separate >> simulations (inside 1 process) where one is called the driver and the other >> is the 'real' test system. >> Since networking requires at least two systems, you usually use --dual >> when you want to test the network. Because gem5 is not yet multi-threaded >> (I think), both simulations end up using only 1 core. >> Hence, ideally this should result in a 2x slowdown. However, I'm seeing a >> lot more. That's what my question was about. >> >> My single system simulations also take about 12-15 hours to complete. >> With detailed they take a lot longer (haven't fully completed a sim yet). >> >> Regards >> Guru >> >> >> >> On Mon, Aug 3, 2015 at 12:42 PM, Davesh Shingari < >> [email protected]> wrote: >> >>> Just to be sure,what do you mean by dual? >>> Do you mean 2 simulation or multiple core configuration? >>> ᐧ >>> >>> On Mon, Aug 3, 2015 at 9:39 AM, Guru Prasad <[email protected]> >>> wrote: >>> >>>> Hi Davesh, just to clarify, is this with --dual? >>>> >>>> Regards >>>> Guru >>>> >>>> >>>> On Mon, Aug 3, 2015 at 12:38 PM, Davesh Shingari < >>>> [email protected]> wrote: >>>> >>>>> Hi Guru >>>>> >>>>> I am using Android on Gem5 for my work. When I use the simulation to >>>>> take checkpoint, then it takes around 12 - 15 hours to get checkpoint and >>>>> finish simulation. The simulation time is 32 seconds after the checkpoint. >>>>> But when I use that checkpoint along with detailed mode configuration and >>>>> full memory system, then it takes almost a week to complete. >>>>> ᐧ >>>>> >>>>> On Mon, Aug 3, 2015 at 9:23 AM, Guru Prasad <[email protected]> >>>>> wrote: >>>>> >>>>>> Ah I see. It sounds like the sort of like the hack we made for hdlcd >>>>>> where we read from physical memory directly. >>>>>> >>>>>> Thanks once again. I will try the options you've described. >>>>>> >>>>>> Regards >>>>>> Guru >>>>>> >>>>>> >>>>>> On Mon, Aug 3, 2015 at 12:19 PM, Andreas Hansson >>>>>> <[email protected]> wrote: >>>>>> > Hi Guru, >>>>>> > >>>>>> > 3 days for 20 seconds sounds way slower than it should be. >>>>>> > >>>>>> > Fast-mem is not replacing the DRAM controller, it bypasses the >>>>>> entire >>>>>> > memory system. In atomic we do not do any sensible timing >>>>>> simulation of >>>>>> > the controller in any case. >>>>>> > >>>>>> > The KVM CPU is only built if your system support it. Hence, you >>>>>> need to >>>>>> > build gem5 for ARM on an ARM system. A good reason to get an ARM >>>>>> server :-) >>>>>> > >>>>>> > Andreas >>>>>> > >>>>>> > On 03/08/2015 16:46, "gem5-users on behalf of Guru Prasad" >>>>>> > <[email protected] on behalf of [email protected]> >>>>>> wrote: >>>>>> > >>>>>> >>Hi Andreas, >>>>>> >> >>>>>> >>Thanks for the suggestions. It took about 3 days to simulate >>>>>> 20seconds >>>>>> >>under atomic. >>>>>> >>I don't know how to tell if interrupts are being lost. The kernel is >>>>>> >>not complaining about anything on kmsg. >>>>>> >>I will try atomic with --fast-mem. Currently, I've been using >>>>>> >>lpddr3_1600_x32 >>>>>> >> >>>>>> >>I don't think I have KvmArmCPU available. I will try the same with >>>>>> the >>>>>> >>latest. >>>>>> >>Is using KvmArmCPU as simple as just saying --cpu-type=...? >>>>>> >>I ask this because --list-cpu-types for my current version only >>>>>> displays >>>>>> >> timing => TimingSimpleCPU >>>>>> >> detailed => DerivO3CPU >>>>>> >> atomic => AtomicSimpleCPU >>>>>> >> minor => MinorCPU >>>>>> >> >>>>>> >> >>>>>> >>Regards >>>>>> >>Guru >>>>>> >> >>>>>> >>On Mon, Aug 3, 2015 at 11:33 AM, Andreas Hansson >>>>>> >><[email protected]> wrote: >>>>>> >>> Hi Guru, >>>>>> >>> >>>>>> >>> To speed things up, here are some options: >>>>>> >>> >>>>>> >>> 1. Use atomic to get the point of interest, then take a >>>>>> checkpoint. Is >>>>>> >>> this what you are doing? >>>>>> >>> >>>>>> >>> 2. For the above, run with --fast-mem since you’re not warming any >>>>>> >>>caches >>>>>> >>> anyways. >>>>>> >>> >>>>>> >>> 3. If possible, use the KvmArmCPU instead of (1). This should >>>>>> give you a >>>>>> >>> significant boost. >>>>>> >>> >>>>>> >>> If the amount of work is constant, than running with dual should >>>>>> not >>>>>> >>>slow >>>>>> >>> things down. If you’re seeing a slow down, then perhaps something >>>>>> odd is >>>>>> >>> going on in the simulation (interrupts getting lost etc). Have >>>>>> you tried >>>>>> >>> with the latest trunk? >>>>>> >>> >>>>>> >>> Andreas >>>>>> >>> >>>>>> >>> >>>>>> >>> On 03/08/2015 16:16, "gem5-users on behalf of Guru Prasad" >>>>>> >>> <[email protected] on behalf of [email protected]> >>>>>> wrote: >>>>>> >>> >>>>>> >>>>Hi, >>>>>> >>>> >>>>>> >>>>Recently we've been trying to run some experiments with the >>>>>> network. >>>>>> >>>>To do so, we've been using dual simulations. So far, we've been >>>>>> able >>>>>> >>>>to get away with running two simulations booting barebones linux >>>>>> with >>>>>> >>>>just a shell. However, our real workload is BBench and so we need >>>>>> to >>>>>> >>>>boot a full Android image. >>>>>> >>>> >>>>>> >>>>A single simulation of full Android takes us about ~12hours to >>>>>> boot. >>>>>> >>>>However under dual, its been about 3 days and has so far simulated >>>>>> >>>>only ~20seconds. Is there any way to speed up the simulation? Is >>>>>> there >>>>>> >>>>any way we can stitch two single simulations together (initial >>>>>> loss of >>>>>> >>>>time on drivesys is acceptable). >>>>>> >>>> >>>>>> >>>>Currently we're on revision e179497451. >>>>>> >>>> >>>>>> >>>>Regards >>>>>> >>>>Guru >>>>>> >>>>_______________________________________________ >>>>>> >>>>gem5-users mailing list >>>>>> >>>>[email protected] >>>>>> >>>>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 >>>>>> >>> [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 >>>>>> > >>>>>> > >>>>>> > -- 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 >>>>>> > [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 >>>>>> >>>>> >>>>> >>>>> >>>>> -- >>>>> Have a great day! >>>>> >>>>> Thanks and Warm Regards >>>>> Davesh Shingari >>>>> Master's in Computer Engineering [EE] >>>>> Arizona State University >>>>> >>>>> [email protected] >>>>> >>>>> _______________________________________________ >>>>> 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 >>>> >>> >>> >>> >>> -- >>> Have a great day! >>> >>> Thanks and Warm Regards >>> Davesh Shingari >>> Master's in Computer Engineering [EE] >>> Arizona State University >>> >>> [email protected] >>> >>> _______________________________________________ >>> 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 >> > > > > -- > Have a great day! > > Thanks and Warm Regards > Davesh Shingari > Master's in Computer Engineering [EE] > Arizona State University > > [email protected] > > _______________________________________________ > 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
