Hi, Alex Thanks for your attention. Following I will share how to measure the power savings in Arm:
1.Test Setup: 1.1 ensure the dpdk version has been applied the wfe patch: http://patches.dpdk.org/project/dpdk/cover/20230220085109.3463640-1-feifei.wa...@arm.com/ This is due to dpdk cannot support l3fwd-power 'power monitor' in arm before this patch 1.2 enable wfe instructions in arm: dpdk/config/arm/meson.build: 'RTE_ARM_USE_WFE', false -> 'RTE_ARM_USE_WFE', true 1.3 build l3fwd-power meson -Dexamples=l3fwd-power build && cd build && ninja 2. Test Command: L3fwd-power uses 'power monitor' mode sudo ./examples/dpdk-l3fwd-power -l 14-15 -n 4 -a 0000:13:00.0 -a 0000:13:00.1 -- -p 0x3 -P --config='(0,0,14),(1,0,15)' --pmd-mgmt=monitor note: power monitor can just support more than 1 cores. 3. Power saving count: For arm, wfe instructions can let CPU go into sleeping mode if it is always idle. Thus, we have 2 ways to collect power saving info. 3.1 Using perf to record dynamic instruction number within 1 second: $sudo perf stat -C <cpu id>, and then we can get CPU instructions number during a fixed time slot. For examples: Performance counter stats for 'CPU(s) 14': 3,506.56 msec cpu-clock # 1.000 CPUs utilized 0 context-switches # 0.000 K/sec 0 cpu-migrations # 0.000 K/sec 0 page-faults # 0.000 K/sec 8,768,815,778 cycles # 2.501 GHz 26,071,802 instructions # 0.00 insn per cycle <not supported> branches 104,982 branch-misses 3.506978873 seconds time elapsed Dynamic instructions number for 1 second = 26,071,802/3.506978873 If we disable wfe in arm, we can find 'dynamic instructions number for 1 second' increases significantly. This also means CPU is running at full load. 3.2 Get CPU power form BMC: For ampere altra and thunderx2 server, we can look up CPU timely power from BMC. For example, when we run l3fwd-power in thunderx2, server information->power->consumption: ----------------------------------------------------------------------------------- CPU0 Current Power Consumption 69 W | 235 BTU/hr CPU1 Current Power Consumption 0 W | 0 BTU/hr CPU Power Limit Management Activated CPU Power Limit in Watts(1-150) ----------------------------------------------------------------------------------- If we disable wfe, CPU0 Current Power Consumption will increase, then we can know how much power we can save. Best Regards Feifei > -----Original Message----- > From: Alexander Kozyrev <akozy...@nvidia.com> > Sent: Saturday, April 1, 2023 1:29 AM > To: Feifei Wang <feifei.wa...@arm.com>; Ruifeng Wang > <ruifeng.w...@arm.com> > Cc: dev@dpdk.org > Subject: RE: ARM power-saving measurements > > Hi Feifei/Ruifeng, any advice on power saving measurements on ARM? > > Regards, > Alex > > > -----Original Message----- > > From: Alexander Kozyrev > > Sent: March 13, 2023 18:08 > > To: Feifei Wang <feifei.wa...@arm.com>; ruifeng.w...@arm.com > > Subject: ARM power-saving measurements > > > > Hi Feifei/ Ruifeng, I can see that power management support on ARM has > > been integrated successfully. > > Could you please share the knowledge on how to measure the power > > savings on this architecture? > > What are the tools available there? Unfortunately, turbostat is not > > supported on ARM. How did you test your feature? > > > > Regards, > > Alex
