Re: [gem5-users] How to use multiple channels in gem5
Hi Nitish, I also have a similar setup of HBM with 8 memory channels, using ARM FS simulation without any Ruby. I am running the STREAM benchmark to see the bandwidth improvements w.r.t to DDR4 in an 8 core simulation. I did not see any improvements for both ARM Minor and O3 cpu models. After checking the gem5 stats, I saw that only one of the 7 channels was being used and stressed. I increased the memory allocated by STREAM to use atleast 50% of the memory (2.2GB out 4G), but still I only see that only one channel is being used. I am investigating it further and will let you know if I figure out anything. I suspect it might me a problem with the channel interleaving in configs/common/MemConfig.py, but I am not sure at this moment. If anyone has any idea it would be why is only one channel being used, it would be great to share. The command line is as follows ./build/ARM/gem5.fast --remote-gdb-port=0 -d stream_8_ch_8_cpu/in_8_cpu_hbm_l2_1GHZ configs/example/fs.py --cpu-clock=1GHz --kernel=vmlinux --machine-type=VExpress_GEM5_V1 --dtb-file=/home/yqureshi/shares/local/scrap/gem5/system/arm/dt/armv8_gem5_v1_8cpu.dtb -n 8 --disk-image=test_image.img --caches --l2cache --l1i_size=32kB --l1d_size=32kB --l2_size=1MB --l2_assoc=2 --mem-type=HBM_1000_4H_1x128 --mem-ranks=1 --mem-channels=8 --mem-size=4GB --sys-clock=1600MHz -r 1 --cpu-type=MinorCPU Regards Yasir From: gem5-users [mailto:gem5-users-boun...@gem5.org] On Behalf Of Pouya Fotouhi Sent: 14 March 2019 01:42 To: gem5 users mailing list Subject: Re: [gem5-users] How to use multiple channels in gem5 Hi, I suspect Nitish is using Ruby since Ruby "ignores" the number of channels. (look at configs/ruby/Ruby.py and configs/common/MemConfig.py) To have this done with Ruby, you may want to create an Xbar with multiple "memory channels" connected to it and then connect the Xbar to the directory's memory port. Best, On Wed, Mar 13, 2019 at 5:22 PM Venkata Yaswanth Raparti mailto:yaswa...@rams.colostate.edu>> wrote: Hi, Have you tried with different applications? Sometimes it could be that the application doesnt need many channels. On Wed, Mar 13, 2019, 2:55 PM Nitish Srivastava mailto:nk...@cornell.edu>> wrote: [Image removed by sender.] Hi, I am trying to use HBM_1000_4H_1x64 DRAM model with 8 channels. I do this by passing "--mem-type=HBM_1000_4H_1x64 --mem-channels=8" parameters while running gem5 simulation. However, I am not getting any performance improvement by increasing the number of channels. Do I need to do something else to make use of these channels? Some kind of address mapping scheme for the stored data? Please let me know if you have suggestions. Any help will be appreciated. Thanks, Nitish ___ 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 -- Pouya Fotouhi PhD Candidate Department of Electrical and Computer Engineering University of California, Davis ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] How to use multiple channels in gem5
Hi, I suspect Nitish is using Ruby since Ruby "ignores" the number of channels. (look at configs/ruby/Ruby.py and configs/common/MemConfig.py) To have this done with Ruby, you may want to create an Xbar with multiple "memory channels" connected to it and then connect the Xbar to the directory's memory port. Best, On Wed, Mar 13, 2019 at 5:22 PM Venkata Yaswanth Raparti < yaswa...@rams.colostate.edu> wrote: > Hi, > > Have you tried with different applications? Sometimes it could be that the > application doesnt need many channels. > > On Wed, Mar 13, 2019, 2:55 PM Nitish Srivastava wrote: > >> Hi, >> >> I am trying to use HBM_1000_4H_1x64 DRAM model with 8 channels. I do this >> by passing "--mem-type=HBM_1000_4H_1x64 --mem-channels=8" parameters while >> running gem5 simulation. However, I am not getting any performance >> improvement by increasing the number of channels. Do I need to do something >> else to make use of these channels? Some kind of address mapping scheme for >> the stored data? >> >> Please let me know if you have suggestions. Any help will be appreciated. >> >> Thanks, >> Nitish >> >> >> >> ___ >> 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 -- Pouya Fotouhi PhD Candidate Department of Electrical and Computer Engineering University of California, Davis ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
Re: [gem5-users] How to use multiple channels in gem5
Hi, Have you tried with different applications? Sometimes it could be that the application doesnt need many channels. On Wed, Mar 13, 2019, 2:55 PM Nitish Srivastava wrote: > Hi, > > I am trying to use HBM_1000_4H_1x64 DRAM model with 8 channels. I do this > by passing "--mem-type=HBM_1000_4H_1x64 --mem-channels=8" parameters while > running gem5 simulation. However, I am not getting any performance > improvement by increasing the number of channels. Do I need to do something > else to make use of these channels? Some kind of address mapping scheme for > the stored data? > > Please let me know if you have suggestions. Any help will be appreciated. > > Thanks, > Nitish > > > > ___ > 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
Re: [gem5-users] How to use multiple channels in gem5
HI Nitish, Can you provide the full command line that you are using? Thanks, Wendy From: gem5-users on behalf of Nitish Srivastava Reply-To: gem5 users mailing list Date: Wednesday, March 13, 2019 at 4:55 PM To: "gem5-users@gem5.org" Subject: [gem5-users] How to use multiple channels in gem5 [Image removed by sender.] Hi, I am trying to use HBM_1000_4H_1x64 DRAM model with 8 channels. I do this by passing "--mem-type=HBM_1000_4H_1x64 --mem-channels=8" parameters while running gem5 simulation. However, I am not getting any performance improvement by increasing the number of channels. Do I need to do something else to make use of these channels? Some kind of address mapping scheme for the stored data? Please let me know if you have suggestions. Any help will be appreciated. Thanks, Nitish 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 http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
[gem5-users] How to use multiple channels in gem5
Hi, I am trying to use HBM_1000_4H_1x64 DRAM model with 8 channels. I do this by passing "--mem-type=HBM_1000_4H_1x64 --mem-channels=8" parameters while running gem5 simulation. However, I am not getting any performance improvement by increasing the number of channels. Do I need to do something else to make use of these channels? Some kind of address mapping scheme for the stored data? Please let me know if you have suggestions. Any help will be appreciated. Thanks, Nitish ___ gem5-users mailing list gem5-users@gem5.org http://m5sim.org/cgi-bin/mailman/listinfo/gem5-users
