Re: [gem5-dev] simpoints and KVM
Hi Mike, When you say KVM enabled, I presume you mean running the KvmCPU? As Mitch points out the problem is that you need something to attach the SimPoint probe to, and the KvmCPU does not have that functionality. Andreas On 13/01/2015 00:36, Mitch Hayenga via gem5-dev gem5-dev@gem5.org wrote: Hi Mike, I'm the one who wrote the initial version of the simpoint collection/generation a few years ago. I enforced the fastmem option primarily because I didn't see it necessary to simulate caches during simpoint generation and it made simulation faster. You can simply disable this and it should all still work. For the --cpu-type=atomic option, initially simpoints were hardcoded directly into the atomic CPU. Since then, they've been changed to use the probe system. However, a quick grep of the code shows the initialization for the SimPoint probe only exists in the atomic CPU. If you registered the probe point with the TimingCPU as well, then that should work (I think). On Mon, Jan 12, 2015 at 5:02 PM, mike upton via gem5-dev gem5-dev@gem5.org wrote: I am trying to enable simpoint generation with kvm enabled. Is there anything that inherently blocks this? Simpoints are currently enabled only with --fastmem and --cpu-type=atomic. How fundamental are each of these restrictions? Thanks, Mike ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev -- 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-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
Re: [gem5-dev] simpoints and KVM
Oh, Bummer. I was hoping to be able to get simpoints out of a KvmCPU run. It seems like that is not possible. Is it possible to generate checkpoints using the KvmCPU? If so, I can run the benchmark once with the kvm, generating checkpoints every N billion instructions. I can then run each of those large samples in parallel to generate the simpoints. There will be some sample redundancy, but that is not a huge concern for me at this point. On Tue, Jan 13, 2015 at 12:11 AM, Andreas Hansson via gem5-dev gem5-dev@gem5.org wrote: Hi Mike, When you say KVM enabled, I presume you mean running the KvmCPU? As Mitch points out the problem is that you need something to attach the SimPoint probe to, and the KvmCPU does not have that functionality. Andreas On 13/01/2015 00:36, Mitch Hayenga via gem5-dev gem5-dev@gem5.org wrote: Hi Mike, I'm the one who wrote the initial version of the simpoint collection/generation a few years ago. I enforced the fastmem option primarily because I didn't see it necessary to simulate caches during simpoint generation and it made simulation faster. You can simply disable this and it should all still work. For the --cpu-type=atomic option, initially simpoints were hardcoded directly into the atomic CPU. Since then, they've been changed to use the probe system. However, a quick grep of the code shows the initialization for the SimPoint probe only exists in the atomic CPU. If you registered the probe point with the TimingCPU as well, then that should work (I think). On Mon, Jan 12, 2015 at 5:02 PM, mike upton via gem5-dev gem5-dev@gem5.org wrote: I am trying to enable simpoint generation with kvm enabled. Is there anything that inherently blocks this? Simpoints are currently enabled only with --fastmem and --cpu-type=atomic. How fundamental are each of these restrictions? Thanks, Mike ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev -- 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-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
Re: [gem5-dev] simpoints and KVM
That is doable. You can created checkpoints, there is just no way to instrument every basic-block. Ali On 1/13/15, 3:13 PM, mike upton via gem5-dev gem5-dev@gem5.org wrote: Oh, Bummer. I was hoping to be able to get simpoints out of a KvmCPU run. It seems like that is not possible. Is it possible to generate checkpoints using the KvmCPU? If so, I can run the benchmark once with the kvm, generating checkpoints every N billion instructions. I can then run each of those large samples in parallel to generate the simpoints. There will be some sample redundancy, but that is not a huge concern for me at this point. On Tue, Jan 13, 2015 at 12:11 AM, Andreas Hansson via gem5-dev gem5-dev@gem5.org wrote: Hi Mike, When you say KVM enabled, I presume you mean running the KvmCPU? As Mitch points out the problem is that you need something to attach the SimPoint probe to, and the KvmCPU does not have that functionality. Andreas On 13/01/2015 00:36, Mitch Hayenga via gem5-dev gem5-dev@gem5.org wrote: Hi Mike, I'm the one who wrote the initial version of the simpoint collection/generation a few years ago. I enforced the fastmem option primarily because I didn't see it necessary to simulate caches during simpoint generation and it made simulation faster. You can simply disable this and it should all still work. For the --cpu-type=atomic option, initially simpoints were hardcoded directly into the atomic CPU. Since then, they've been changed to use the probe system. However, a quick grep of the code shows the initialization for the SimPoint probe only exists in the atomic CPU. If you registered the probe point with the TimingCPU as well, then that should work (I think). On Mon, Jan 12, 2015 at 5:02 PM, mike upton via gem5-dev gem5-dev@gem5.org wrote: I am trying to enable simpoint generation with kvm enabled. Is there anything that inherently blocks this? Simpoints are currently enabled only with --fastmem and --cpu-type=atomic. How fundamental are each of these restrictions? Thanks, Mike ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev -- 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-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev -- 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-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
Re: [gem5-dev] simpoints and KVM
Hi Mike, I'm the one who wrote the initial version of the simpoint collection/generation a few years ago. I enforced the fastmem option primarily because I didn't see it necessary to simulate caches during simpoint generation and it made simulation faster. You can simply disable this and it should all still work. For the --cpu-type=atomic option, initially simpoints were hardcoded directly into the atomic CPU. Since then, they've been changed to use the probe system. However, a quick grep of the code shows the initialization for the SimPoint probe only exists in the atomic CPU. If you registered the probe point with the TimingCPU as well, then that should work (I think). On Mon, Jan 12, 2015 at 5:02 PM, mike upton via gem5-dev gem5-dev@gem5.org wrote: I am trying to enable simpoint generation with kvm enabled. Is there anything that inherently blocks this? Simpoints are currently enabled only with --fastmem and --cpu-type=atomic. How fundamental are each of these restrictions? Thanks, Mike ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev ___ gem5-dev mailing list gem5-dev@gem5.org http://m5sim.org/mailman/listinfo/gem5-dev
