There are two problems with exynos-nocp driver. First one is reading bytes and cycle counters and comparing them one to one without taking into account wcore bus width. Second one is that cycle counter depends on DREX DRAM clock, not on wcore clock. The latter problem was exposed by commit 6e7674c3c6df5 ("memory: Add DMC driver for Exynos5422"), which changes DRAM clock depending on memory read/write pressure and when it gets at higher freqency, NoCP cycle counter also increases. Note that both of these problems was there before this commit. The proposed solution is to use byte counter from NoCP h/w registers for current wcore bandwidth calculations and derive max bandwidth from current frequency. While at it, change from bytes to kilobytes to avoid overflow in later calculations in exynos-bus and devfreq drivers. --- All tests were run on Odroid XU3 with Exynos 5422 SoC. FullHD monitor was connected. Three programs were used for tests: stream for memory stress (no wcore activity), dd with eMMC read and modetest (both dd and modetest generate data transfers through wcore). First test was performed on idle system without running any mentioned programs. In all tests there was applied "PM / devfreq: add possibility for delayed work", so data from dev_dbg are printed at regular intervals ~60ms. Below is first test without current patchset with idle system. Change of governor from powersave to performance makes wcore frequency change from 88MHz to 532MHz but cycle counter keeps at 4,9*10^6. Additionally, byte/cycle ratio also keeps around 310% (15285144 * 100 / 4915741). # mkdir /mnt/debug # mount -tdebugfs debug /mnt/debug/ # echo -n 'file exynos-nocp.c +p' > /mnt/debug/dynamic_debug/control root@target:~/devfreq# uname -a Linux target 5.5.0-rc5-next-20200113-00004-g1374a52f3252 #89 SMP PREEMPT Wed Jan 22 15:14:17 CET 2020 armx root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/available_governors userspace powersave performance simple_ondemand root@target:~/devfreq# echo powersave > /sys/class/devfreq/devfreq2/governor root@target:~/devfreq# sleep 1 root@target:~/devfreq# dmesg|tail [ 537.340710] devfreq-event event2: nocp@10ca1800 (event: 15110160/4980473) [ 537.340749] devfreq-event event3: nocp@10ca1c00 (event: 0/4910429) [ 537.400676] devfreq-event event0: nocp@10ca1000 (event: 15386976/4936165) [ 537.400731] devfreq-event event1: nocp@10ca1400 (event: 0/4934961) [ 537.400783] devfreq-event event2: nocp@10ca1800 (event: 15167708/4933305) [ 537.400834] devfreq-event event3: nocp@10ca1c00 (event: 0/4931505) [ 537.460635] devfreq-event event0: nocp@10ca1000 (event: 15523208/4924365) [ 537.460678] devfreq-event event1: nocp@10ca1400 (event: 0/4920169) [ 537.460717] devfreq-event event2: nocp@10ca1800 (event: 15285144/4915741) [ 537.460755] devfreq-event event3: nocp@10ca1c00 (event: 0/4911197) root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) * 88700000: 0 0 0 0 1 77030 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 532000000: 1 0 0 0 0 513100 Total transition : 2 root@target:~/devfreq# echo performance > /sys/class/devfreq/devfreq2/governor root@target:~/devfreq# sleep 1 root@target:~/devfreq# dmesg|tail [ 537.340710] devfreq-event event2: nocp@10ca1800 (event: 15110160/4980473) [ 537.340749] devfreq-event event3: nocp@10ca1c00 (event: 0/4910429) [ 537.400676] devfreq-event event0: nocp@10ca1000 (event: 15386976/4936165) [ 537.400731] devfreq-event event1: nocp@10ca1400 (event: 0/4934961) [ 537.400783] devfreq-event event2: nocp@10ca1800 (event: 15167708/4933305) [ 537.400834] devfreq-event event3: nocp@10ca1c00 (event: 0/4931505) [ 537.460635] devfreq-event event0: nocp@10ca1000 (event: 15523208/4924365) [ 537.460678] devfreq-event event1: nocp@10ca1400 (event: 0/4920169) [ 537.460717] devfreq-event event2: nocp@10ca1800 (event: 15285144/4915741) [ 537.460755] devfreq-event event3: nocp@10ca1c00 (event: 0/4911197) root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 2 398100 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 1 0 0 0 0 524440 Total transition : 3 --- Below are logs from memory stress stream running on linux next-20200113 and applied patchset "PM / devfreq: add possibility for delayed work" with config option DEVFREQ_DELAYED_TIMER set on but without current patchset. After end of stream program, cycle counter drops gradually from 24*10^6 to 22*10^6, 18*10^6, 16*10^6, 12*10^6, 8*10^6. These corresponds to DRAM frequences, while bytes counts stays around 15*10^6, with debug prints in 60ms periods. Wcore frequency keeps at 532MHz. It shows that NoCP cycle counters counts DREX cycles. root@target:~# cat /sys/class/devfreq/devfreq0/name 10c20000.memory-controller root@target:~# cat /sys/class/devfreq/devfreq0/available_frequencies 165000000 206000000 275000000 413000000 543000000 633000000 728000000 825000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/name soc:bus_wcore root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19600 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 0 0 0 0 0 276830 Total transition : 1 [3]+ Done ../stream_gnueabi root@target:~/devfreq# dmesg|tail [ 408.795693] devfreq-event event2: nocp@10ca1800 (event: 15439456/24502701) [ 408.795756] devfreq-event event3: nocp@10ca1c00 (event: 0/24462297) [ 408.855906] devfreq-event event0: nocp@10ca1000 (event: 15676712/24742161) [ 408.856058] devfreq-event event1: nocp@10ca1400 (event: 0/24779693) [ 408.856200] devfreq-event event2: nocp@10ca1800 (event: 15412224/24806561) [ 408.856339] devfreq-event event3: nocp@10ca1c00 (event: 0/24832709) [ 408.915511] devfreq-event event0: nocp@10ca1000 (event: 15529520/24311941) [ 408.915543] devfreq-event event1: nocp@10ca1400 (event: 0/24313465) [ 408.915572] devfreq-event event2: nocp@10ca1800 (event: 15126880/24182937) [ 408.915602] devfreq-event event3: nocp@10ca1c00 (event: 0/24182621) root@target:~/devfreq# dmesg|tail [ 409.465639] devfreq-event event2: nocp@10ca1800 (event: 15399964/22002313) [ 409.465690] devfreq-event event3: nocp@10ca1c00 (event: 0/21989117) [ 409.525424] devfreq-event event0: nocp@10ca1000 (event: 15671172/18876933) [ 409.525451] devfreq-event event1: nocp@10ca1400 (event: 0/18863021) [ 409.525476] devfreq-event event2: nocp@10ca1800 (event: 15389640/18848269) [ 409.525501] devfreq-event event3: nocp@10ca1c00 (event: 0/18833213) [ 409.585407] devfreq-event event0: nocp@10ca1000 (event: 15615780/18943765) [ 409.585430] devfreq-event event1: nocp@10ca1400 (event: 0/18939237) [ 409.585451] devfreq-event event2: nocp@10ca1800 (event: 15311112/18933717) [ 409.585473] devfreq-event event3: nocp@10ca1c00 (event: 0/18928025) root@target:~/devfreq# dmesg|tail [ 410.195489] devfreq-event event2: nocp@10ca1800 (event: 15456592/18901525) [ 410.195513] devfreq-event event3: nocp@10ca1c00 (event: 0/18890417) [ 410.255525] devfreq-event event0: nocp@10ca1000 (event: 15641556/18975417) [ 410.255571] devfreq-event event1: nocp@10ca1400 (event: 0/18979225) [ 410.255616] devfreq-event event2: nocp@10ca1800 (event: 15350596/18981701) [ 410.255659] devfreq-event event3: nocp@10ca1c00 (event: 0/18983885) [ 410.315492] devfreq-event event0: nocp@10ca1000 (event: 15722964/18910573) [ 410.315523] devfreq-event event1: nocp@10ca1400 (event: 0/18900445) [ 410.315552] devfreq-event event2: nocp@10ca1800 (event: 15392616/18888593) [ 410.315582] devfreq-event event3: nocp@10ca1c00 (event: 0/18877473) root@target:~/devfreq# dmesg|tail [ 410.915913] devfreq-event event2: nocp@10ca1800 (event: 15284056/16183805) [ 410.916053] devfreq-event event3: nocp@10ca1c00 (event: 0/16191953) [ 410.975616] devfreq-event event0: nocp@10ca1000 (event: 15643540/16119365) [ 410.975678] devfreq-event event1: nocp@10ca1400 (event: 0/16092877) [ 410.975731] devfreq-event event2: nocp@10ca1800 (event: 15310112/16070749) [ 410.975818] devfreq-event event3: nocp@10ca1c00 (event: 0/16058261) [ 411.035711] devfreq-event event0: nocp@10ca1000 (event: 15568372/16212845) [ 411.035736] devfreq-event event1: nocp@10ca1400 (event: 0/16170909) [ 411.035759] devfreq-event event2: nocp@10ca1800 (event: 15207864/16139825) [ 411.035781] devfreq-event event3: nocp@10ca1c00 (event: 0/16100285) root@target:~/devfreq# dmesg|tail [ 411.695736] devfreq-event event2: nocp@10ca1800 (event: 15307112/12243577) [ 411.695799] devfreq-event event3: nocp@10ca1c00 (event: 0/12215505) [ 411.755546] devfreq-event event0: nocp@10ca1000 (event: 15492580/12310437) [ 411.755594] devfreq-event event1: nocp@10ca1400 (event: 0/12302877) [ 411.755628] devfreq-event event2: nocp@10ca1800 (event: 15195176/12290805) [ 411.755662] devfreq-event event3: nocp@10ca1c00 (event: 0/12277981) [ 411.815659] devfreq-event event0: nocp@10ca1000 (event: 15663508/12364637) [ 411.815742] devfreq-event event1: nocp@10ca1400 (event: 0/12372049) [ 411.815819] devfreq-event event2: nocp@10ca1800 (event: 15363208/12377025) [ 411.815895] devfreq-event event3: nocp@10ca1c00 (event: 0/12382285) root@target:~/devfreq# dmesg|tail [ 412.475472] devfreq-event event2: nocp@10ca1800 (event: 15336068/8174697) [ 412.475500] devfreq-event event3: nocp@10ca1c00 (event: 0/8166397) [ 412.535552] devfreq-event event0: nocp@10ca1000 (event: 15559072/8245049) [ 412.535606] devfreq-event event1: nocp@10ca1400 (event: 0/8246885) [ 412.535644] devfreq-event event2: nocp@10ca1800 (event: 15300092/8245173) [ 412.535682] devfreq-event event3: nocp@10ca1c00 (event: 0/8243145) [ 412.595670] devfreq-event event0: nocp@10ca1000 (event: 15707976/8233633) [ 412.595757] devfreq-event event1: nocp@10ca1400 (event: 0/8238765) [ 412.595836] devfreq-event event2: nocp@10ca1800 (event: 15463796/8241561) [ 412.595916] devfreq-event event3: nocp@10ca1c00 (event: 0/8244441) root@target:~/devfreq# --- Logs from dd program without patchset: root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19600 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 0 0 0 0 0 636660 Total transition : 1 uname -a Linux target 5.5.0-rc5-next-20200113-00004-g1374a52f3252 #89 SMP PREEMPT Wed Jan 22 15:14:17 CET 2020 armv7l GNU/Linux root@target:~# cat /sys/class/devfreq/devfreq0/available_frequencies 165000000 206000000 275000000 413000000 543000000 633000000 728000000 825000000 root@target:~# cat /sys/class/devfreq/devfreq0/governor simple_ondemand root@target:~# cat /sys/class/devfreq/devfreq0/name 10c20000.memory-controller root@target:~# cat /sys/class/devfreq/devfreq2/name soc:bus_wcore root@target:~# cat /sys/class/devfreq/devfreq2/governor simple_ondemand root@target:~# cat /sys/class/devfreq/devfreq2/available_governors userspace powersave performance simple_ondemand root@target:~# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 21890 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 0 0 0 0 0 148180 Total transition : 1 root@target:~# dd if=/dev/mmcblk0p5 of=/dev/null & root@target:~/devfreq# dmesg|tail [ 203.960365] devfreq-event event2: nocp@10ca1800 (event: 16527152/4949925) [ 203.960404] devfreq-event event3: nocp@10ca1c00 (event: 0/4947305) [ 204.020027] devfreq-event event0: nocp@10ca1000 (event: 16682948/4909245) [ 204.020082] devfreq-event event1: nocp@10ca1400 (event: 0/4910441) [ 204.020228] devfreq-event event2: nocp@10ca1800 (event: 16489972/4916613) [ 204.020272] devfreq-event event3: nocp@10ca1c00 (event: 0/4914745) [ 204.080072] devfreq-event event0: nocp@10ca1000 (event: 16478288/4924185) [ 204.080132] devfreq-event event1: nocp@10ca1400 (event: 0/4925193) [ 204.080182] devfreq-event event2: nocp@10ca1800 (event: 16264096/4923477) [ 204.080230] devfreq-event event3: nocp@10ca1c00 (event: 0/4921769) root@target:~/devfreq# dmesg|tail [ 246.059861] devfreq-event event2: nocp@10ca1800 (event: 20070832/28829017) [ 246.059881] devfreq-event event3: nocp@10ca1c00 (event: 0/28824933) [ 246.129815] devfreq-event event0: nocp@10ca1000 (event: 20427304/28827105) [ 246.129841] devfreq-event event1: nocp@10ca1400 (event: 0/28829773) [ 246.129861] devfreq-event event2: nocp@10ca1800 (event: 20069316/28826285) [ 246.129883] devfreq-event event3: nocp@10ca1c00 (event: 0/28822925) [ 246.189805] devfreq-event event0: nocp@10ca1000 (event: 17431936/24698601) [ 246.189827] devfreq-event event1: nocp@10ca1400 (event: 0/24698561) [ 246.189847] devfreq-event event2: nocp@10ca1800 (event: 17122664/24694697) [ 246.189866] devfreq-event event3: nocp@10ca1c00 (event: 0/24690477) root@target:~/devfreq# dmesg|tail [ 305.689792] devfreq-event event2: nocp@10ca1800 (event: 19897292/28827045) [ 305.689811] devfreq-event event3: nocp@10ca1c00 (event: 0/28823497) [ 305.759748] devfreq-event event0: nocp@10ca1000 (event: 20428188/28829305) [ 305.759772] devfreq-event event1: nocp@10ca1400 (event: 0/28829941) [ 305.759792] devfreq-event event2: nocp@10ca1800 (event: 20069112/28826421) [ 305.759811] devfreq-event event3: nocp@10ca1c00 (event: 0/28822505) [ 305.829759] devfreq-event event0: nocp@10ca1000 (event: 20431388/28833721) [ 305.829784] devfreq-event event1: nocp@10ca1400 (event: 0/28835077) [ 305.829805] devfreq-event event2: nocp@10ca1800 (event: 20072332/28831797) [ 305.829826] devfreq-event event3: nocp@10ca1c00 (event: 0/28828669) root@target:~/devfreq# 22501344+0 records in 22501344+0 records out 11520688128 bytes (12 GB, 11 GiB) copied, 202.816 s, 56.8 MB/s [1]+ Done dd if=/dev/mmcblk0p5 of=/dev/null (wd: ~) (wd now: ~/devfreq) root@target:~/devfreq# dmesg|tail [ 706.099607] devfreq-event event2: nocp@10ca1800 (event: 15308600/4922945) [ 706.099639] devfreq-event event3: nocp@10ca1c00 (event: 0/4919705) [ 706.159726] devfreq-event event0: nocp@10ca1000 (event: 15430964/4950105) [ 706.159782] devfreq-event event1: nocp@10ca1400 (event: 0/4949257) [ 706.159825] devfreq-event event2: nocp@10ca1800 (event: 15213116/4947661) [ 706.159878] devfreq-event event3: nocp@10ca1c00 (event: 0/4946217) [ 706.229632] devfreq-event event0: nocp@10ca1000 (event: 18023796/5745053) [ 706.229674] devfreq-event event1: nocp@10ca1400 (event: 0/5741853) [ 706.229714] devfreq-event event2: nocp@10ca1800 (event: 17752680/5737085) [ 706.229753] devfreq-event event3: nocp@10ca1c00 (event: 0/5732637) root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 21890 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 0 0 0 0 0 682170 Total transition : 1 --- Logs from modetest program without patchset: root@target:~/devfreq# ../modetest -s 43:1920x1080 -P41:1920x1080 & [1] 768 root@target:~/devfreq# trying to open device 'i915'...failed trying to open device 'amdgpu'...failed trying to open device 'radeon'...failed trying to open device 'nouveau'...failed trying to open device 'vmwgfx'...failed trying to open device 'omapdrm'...failed trying to open device 'exynos'...done setting mode 1920x1080-60Hz@XR24 on connectors 43, crtc 41 testing 1920x1080@XR24 overlay plane 36 ^C [1]+ Stopped ../modetest -s 43:1920x1080 -P41:1920x1080 root@target:~/devfreq# dmesg|tail [ 820.619367] devfreq-event event2: nocp@10ca1800 (event: 30328644/24548753) [ 820.619409] devfreq-event event3: nocp@10ca1c00 (event: 0/24524329) [ 820.679405] devfreq-event event0: nocp@10ca1000 (event: 30494152/24711057) [ 820.679449] devfreq-event event1: nocp@10ca1400 (event: 0/24771605) [ 820.679616] devfreq-event event2: nocp@10ca1800 (event: 30235156/24749273) [ 820.679673] devfreq-event event3: nocp@10ca1c00 (event: 0/24749361) [ 820.739321] devfreq-event event0: nocp@10ca1000 (event: 30302840/24562317) [ 820.739347] devfreq-event event1: nocp@10ca1400 (event: 0/24538725) [ 820.739375] devfreq-event event2: nocp@10ca1800 (event: 29936448/24513753) [ 820.739399] devfreq-event event3: nocp@10ca1c00 (event: 0/24490281) root@target:~/devfreq# dmesg|tail [ 839.159763] devfreq-event event2: nocp@10ca1800 (event: 30353968/24842849) [ 839.159823] devfreq-event event3: nocp@10ca1c00 (event: 0/24865157) [ 839.219307] devfreq-event event0: nocp@10ca1000 (event: 30557856/24492825) [ 839.219339] devfreq-event event1: nocp@10ca1400 (event: 0/24471425) [ 839.219369] devfreq-event event2: nocp@10ca1800 (event: 30199176/24448969) [ 839.219398] devfreq-event event3: nocp@10ca1c00 (event: 0/24426201) [ 839.279298] devfreq-event event0: nocp@10ca1000 (event: 30428216/24658369) [ 839.279328] devfreq-event event1: nocp@10ca1400 (event: 0/24653145) [ 839.279356] devfreq-event event2: nocp@10ca1800 (event: 30068856/24616381) [ 839.279383] devfreq-event event3: nocp@10ca1c00 (event: 0/24592713) root@target:~/devfreq# fg %1 ../modetest -s 43:1920x1080 -P41:1920x1080 root@target:~/devfreq# dmesg|tail [ 849.109306] devfreq-event event2: nocp@10ca1800 (event: 15005132/18570965) [ 849.109334] devfreq-event event3: nocp@10ca1c00 (event: 0/18536625) [ 849.169188] devfreq-event event0: nocp@10ca1000 (event: 15774388/18925857) [ 849.169211] devfreq-event event1: nocp@10ca1400 (event: 0/18919609) [ 849.169232] devfreq-event event2: nocp@10ca1800 (event: 15467076/18912721) [ 849.169253] devfreq-event event3: nocp@10ca1c00 (event: 0/18905821) [ 849.229241] devfreq-event event0: nocp@10ca1000 (event: 15638480/18969689) [ 849.229278] devfreq-event event1: nocp@10ca1400 (event: 0/18971713) [ 849.229310] devfreq-event event2: nocp@10ca1800 (event: 15342996/18971197) [ 849.229343] devfreq-event event3: nocp@10ca1c00 (event: 0/18971037) root@target:~/devfreq# dmesg|tail [ 852.689344] devfreq-event event2: nocp@10ca1800 (event: 15166292/6141665) [ 852.689386] devfreq-event event3: nocp@10ca1c00 (event: 0/6139661) [ 852.749342] devfreq-event event0: nocp@10ca1000 (event: 15636760/6165141) [ 852.749401] devfreq-event event1: nocp@10ca1400 (event: 0/6164021) [ 852.749458] devfreq-event event2: nocp@10ca1800 (event: 15390668/6162173) [ 852.749510] devfreq-event event3: nocp@10ca1c00 (event: 0/6225561) [ 852.809320] devfreq-event event0: nocp@10ca1000 (event: 15417248/6147685) [ 852.809396] devfreq-event event1: nocp@10ca1400 (event: 0/6146713) [ 852.809467] devfreq-event event2: nocp@10ca1800 (event: 15171716/6144453) [ 852.809538] devfreq-event event3: nocp@10ca1c00 (event: 0/6141765) root@target:~/devfreq# dmesg|tail [ 856.079392] devfreq-event event2: nocp@10ca1800 (event: 14908768/4852089) [ 856.079437] devfreq-event event3: nocp@10ca1c00 (event: 0/4845833) [ 856.139479] devfreq-event event0: nocp@10ca1000 (event: 15412824/4944089) [ 856.139547] devfreq-event event1: nocp@10ca1400 (event: 0/4943049) [ 856.139620] devfreq-event event2: nocp@10ca1800 (event: 15193496/4941817) [ 856.139694] devfreq-event event3: nocp@10ca1c00 (event: 0/4940997) [ 856.199282] devfreq-event event0: nocp@10ca1000 (event: 15449800/4903065) [ 856.199329] devfreq-event event1: nocp@10ca1400 (event: 0/4896677) [ 856.199372] devfreq-event event2: nocp@10ca1800 (event: 15199216/4889889) [ 856.199408] devfreq-event event3: nocp@10ca1c00 (event: 0/4883005) root@target:~/devfreq# dmesg|tail [ 860.859354] devfreq-event event2: nocp@10ca1800 (event: 15083684/4906997) [ 860.859397] devfreq-event event3: nocp@10ca1c00 (event: 0/4901577) [ 860.919310] devfreq-event event0: nocp@10ca1000 (event: 15551720/4933873) [ 860.919380] devfreq-event event1: nocp@10ca1400 (event: 0/4933309) [ 860.919447] devfreq-event event2: nocp@10ca1800 (event: 15336016/4932153) [ 860.919513] devfreq-event event3: nocp@10ca1c00 (event: 0/4930965) [ 860.979224] devfreq-event event0: nocp@10ca1000 (event: 15315932/4914741) [ 860.979272] devfreq-event event1: nocp@10ca1400 (event: 0/4907993) [ 860.979317] devfreq-event event2: nocp@10ca1800 (event: 15063744/4901321) [ 860.979360] devfreq-event event3: nocp@10ca1c00 (event: 0/4894661) root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 21890 133000000: 0 0 0 0 0 0 177400000: 0 0 0 0 0 0 266000000: 0 0 0 0 0 0 * 532000000: 0 0 0 0 0 873990 Total transition : 1 --- Logs after applied both "PM / devfreq: add possibility for delayed work" and current patchset, tested with three programs: (a) stream, (b) dd from eMMC memory and (c) modetest. (a) stream test (no wcore freq change): root@target:~/devfreq# . nocp_debug exit code: 0 root@target:~/devfreq# dmesg |tail [ 193.344624] devfreq-event event2: nocp@10ca1800 (event: 252318/709600) 60ms 35% 0x00e70110 [ 193.344657] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 193.404790] devfreq-event event0: nocp@10ca1000 (event: 260404/709600) 60ms 36% 0x00ee6854 [ 193.404880] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 193.404956] devfreq-event event2: nocp@10ca1800 (event: 256331/709600) 60ms 36% 0x00eaad94 [ 193.405034] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 193.464521] devfreq-event event0: nocp@10ca1000 (event: 257190/709600) 60ms 36% 0x00eb76f4 [ 193.464556] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 193.464588] devfreq-event event2: nocp@10ca1800 (event: 252946/709600) 60ms 35% 0x00e79468 [ 193.464618] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 20430 133000000: 0 0 0 0 0 0 * 177400000: 0 0 0 0 2 172220 266000000: 0 0 1 0 0 180 532000000: 0 0 2 1 0 220 Total transition : 7 root@target:~/devfreq# ../stream_gnueabi & [1] 733 root@target:~/devfreq# ------------------------------------------------------------- STREAM version $Revision: 5.10 $ ------------------------------------------------------------- This system uses 8 bytes per array element. ------------------------------------------------------------- Array size = 10000000 (elements), Offset = 0 (elements) Memory per array = 76.3 MiB (= 0.1 GiB). Total memory required = 228.9 MiB (= 0.2 GiB). Each kernel will be executed 10 times. The *best* time for each kernel (excluding the first iteration) will be used to compute the reported bandwidth. ------------------------------------------------------------- Your clock granularity/precision appears to be 5 microseconds. Each test below will take on the order of 142436 microseconds. (= 28487 clock ticks) Increase the size of the arrays if this shows that you are not getting at least 20 clock ticks per test. ------------------------------------------------------------- WARNING -- The above is only a rough guideline. For best results, please be sure you know the precision of your system timer. ------------------------------------------------------------- root@target:~/devfreq# dmesg |tail [ 226.928746] devfreq-event event2: nocp@10ca1800 (event: 257500/709600) 60ms 36% 0x00ebbfc4 [ 226.928766] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 226.998460] devfreq-event event0: nocp@10ca1000 (event: 261658/709600) 70ms 36% 0x01177b24 [ 226.998486] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 70ms 0% 0x00000000 [ 226.998507] devfreq-event event2: nocp@10ca1800 (event: 256611/709600) 70ms 36% 0x01121734 [ 226.998527] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 70ms 0% 0x00000000 [ 227.058393] devfreq-event event0: nocp@10ca1000 (event: 260563/709600) 60ms 36% 0x00ee8da4 [ 227.058414] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 227.058433] devfreq-event event2: nocp@10ca1800 (event: 255456/709600) 60ms 36% 0x00e9e0ac [ 227.058450] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# Function Best Rate MB/s Avg time Min time Max time Copy: 4797.5 0.041159 0.033351 0.051780 Scale: 825.3 0.205380 0.193868 0.227955 Add: 1143.5 0.218550 0.209885 0.234103 Triad: 670.2 0.374949 0.358115 0.407750 ------------------------------------------------------------- Solution Validates: avg error less than 1.000000e-13 on all three arrays ------------------------------------------------------------- [1]+ Done ../stream_gnueabi root@target:~/devfreq# dmesg |tail [ 237.444983] devfreq-event event2: nocp@10ca1800 (event: 249059/709600) 60ms 35% 0x00e40568 [ 237.445018] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 237.504918] devfreq-event event0: nocp@10ca1000 (event: 258668/709600) 60ms 36% 0x00ecd184 [ 237.504953] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 237.504994] devfreq-event event2: nocp@10ca1800 (event: 254219/709600) 60ms 35% 0x00e8bec0 [ 237.505029] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 237.564841] devfreq-event event0: nocp@10ca1000 (event: 259859/709600) 60ms 36% 0x00ede874 [ 237.564872] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 237.564898] devfreq-event event2: nocp@10ca1800 (event: 256008/709600) 60ms 36% 0x00ea61f0 [ 237.564923] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 20430 133000000: 0 0 0 0 0 0 * 177400000: 0 0 0 0 2 214770 266000000: 0 0 1 0 0 180 532000000: 0 0 2 1 0 220 Total transition : 7 (b) dd test (wcore enters 2nd freq 266MHz): dmesg |tail [ 1241.311174] devfreq-event event2: nocp@10ca1800 (event: 252036/709600) 60ms 35% 0x00e6bf08 [ 1241.311206] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1241.371136] devfreq-event event0: nocp@10ca1000 (event: 259618/709600) 60ms 36% 0x00edaff8 [ 1241.371168] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1241.371198] devfreq-event event2: nocp@10ca1800 (event: 255889/709600) 60ms 36% 0x00ea460c [ 1241.371229] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1241.431204] devfreq-event event0: nocp@10ca1000 (event: 256887/709600) 60ms 36% 0x00eb2fe4 [ 1241.431240] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1241.431275] devfreq-event event2: nocp@10ca1800 (event: 253194/709600) 60ms 35% 0x00e7ce8c [ 1241.431308] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 * 177400000: 0 0 0 0 4 997330 266000000: 0 0 3 0 0 194010 532000000: 0 1 2 3 0 27930 Total transition : 15 root@target:~/devfreq# dd if=/dev/mmcblk0p5 of=/dev/null & [1] 788 root@target:~/devfreq# dmesg |tail [ 1266.461371] devfreq-event event2: nocp@10ca1800 (event: 273550/709600) 60ms 38% 0x00fa7170 [ 1266.461400] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1266.531256] devfreq-event event0: nocp@10ca1000 (event: 278666/709600) 70ms 39% 0x0129a5e8 [ 1266.531303] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 70ms 0% 0x00000000 [ 1266.531339] devfreq-event event2: nocp@10ca1800 (event: 275211/709600) 70ms 38% 0x0125f530 [ 1266.531372] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 70ms 0% 0x00000000 [ 1266.601314] devfreq-event event0: nocp@10ca1000 (event: 274246/709600) 70ms 38% 0x0124ed54 [ 1266.601375] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 70ms 0% 0x00000000 [ 1266.601417] devfreq-event event2: nocp@10ca1800 (event: 270819/709600) 70ms 38% 0x0121444c [ 1266.601456] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 70ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 177400000: 0 0 0 0 5 1020500 * 266000000: 0 0 3 0 0 200780 532000000: 0 1 2 4 0 28000 Total transition : 17 root@target:~/devfreq# dmesg|tail [ 1297.511213] devfreq-event event2: nocp@10ca1800 (event: 284350/1064000) 60ms 26% 0x010454b0 [ 1297.511228] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 [ 1297.571207] devfreq-event event0: nocp@10ca1000 (event: 292658/1064000) 60ms 27% 0x010befd8 [ 1297.571226] devfreq-event event1: nocp@10ca1400 (event: 0/1064000) 60ms 0% 0x00000000 [ 1297.571242] devfreq-event event2: nocp@10ca1800 (event: 287516/1064000) 60ms 27% 0x01073a94 [ 1297.571258] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 [ 1297.631178] devfreq-event event0: nocp@10ca1000 (event: 288329/1064000) 60ms 27% 0x0107f944 [ 1297.631199] devfreq-event event1: nocp@10ca1400 (event: 0/1064000) 60ms 0% 0x00000000 [ 1297.631221] devfreq-event event2: nocp@10ca1800 (event: 283311/1064000) 60ms 26% 0x01036108 [ 1297.631238] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 177400000: 0 0 0 0 5 1020500 * 266000000: 0 0 3 0 0 268040 532000000: 0 1 2 4 0 28000 Total transition : 17 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat dmesg|tail [ 1345.621291] devfreq-event event2: nocp@10ca1800 (event: 287629/1064000) 60ms 27% 0x01075520 [ 1345.621307] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 [ 1345.681261] devfreq-event event0: nocp@10ca1000 (event: 289991/1064000) 60ms 27% 0x01097ebc [ 1345.681281] devfreq-event event1: nocp@10ca1400 (event: 0/1064000) 60ms 0% 0x00000000 [ 1345.681298] devfreq-event event2: nocp@10ca1800 (event: 284773/1064000) 60ms 26% 0x0104b7d8 [ 1345.681315] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 [ 1345.741266] devfreq-event event0: nocp@10ca1000 (event: 290210/1064000) 60ms 27% 0x0109b214 [ 1345.741286] devfreq-event event1: nocp@10ca1400 (event: 0/1064000) 60ms 0% 0x00000000 [ 1345.741305] devfreq-event event2: nocp@10ca1800 (event: 284920/1064000) 60ms 26% 0x0104da28 [ 1345.741323] devfreq-event event3: nocp@10ca1c00 (event: 0/1064000) 60ms 0% 0x00000000 root@target:~/devfreq# 22501344+0 records in 22501344+0 records out 11520688128 bytes (12 GB, 11 GiB) copied, 205.316 s, 56.1 MB/s [1]+ Done dd if=/dev/mmcblk0p5 of=/dev/null root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 * 177400000: 0 0 0 0 5 1025540 266000000: 0 0 4 0 0 394620 532000000: 0 1 2 4 0 28000 Total transition : 18 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat dmesg|tail [ 1474.562026] devfreq-event event2: nocp@10ca1800 (event: 254570/709600) 60ms 35% 0x00e910e8 [ 1474.562140] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1474.631393] devfreq-event event0: nocp@10ca1000 (event: 255645/709600) 70ms 36% 0x01110f0c [ 1474.631440] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 70ms 0% 0x00000000 [ 1474.631474] devfreq-event event2: nocp@10ca1800 (event: 251797/709600) 70ms 35% 0x010cf2e0 [ 1474.631508] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 70ms 0% 0x00000000 [ 1474.691361] devfreq-event event0: nocp@10ca1000 (event: 257693/709600) 60ms 36% 0x00ebece4 [ 1474.691390] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1474.691416] devfreq-event event2: nocp@10ca1800 (event: 253602/709600) 60ms 35% 0x00e82e2c [ 1474.691441] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 (c) modetest test (wcore enters highest freq): root@target:~/devfreq# dmesg|tail [ 1519.281376] devfreq-event event2: nocp@10ca1800 (event: 244940/709600) 60ms 34% 0x00e04008 [ 1519.281409] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1519.341390] devfreq-event event0: nocp@10ca1000 (event: 258097/709600) 60ms 36% 0x00ec4ba4 [ 1519.341449] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1519.341505] devfreq-event event2: nocp@10ca1800 (event: 254087/709600) 60ms 35% 0x00e89fcc [ 1519.341558] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1519.401322] devfreq-event event0: nocp@10ca1000 (event: 258749/709600) 60ms 36% 0x00ece454 [ 1519.401352] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1519.401382] devfreq-event event2: nocp@10ca1800 (event: 254742/709600) 60ms 35% 0x00e93960 [ 1519.401410] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 * 177400000: 0 0 0 0 5 1073960 266000000: 0 0 4 0 0 394620 532000000: 0 1 2 4 0 28000 Total transition : 18 root@target:~/devfreq# ../modetest -s 43:1920x1080 -P41:1920x1080 & [1] 821 root@target:~/devfreq# trying to open device 'i915'...failed trying to open device 'amdgpu'...failed trying to open device 'radeon'...failed trying to open device 'nouveau'...failed trying to open device 'vmwgfx'...failed trying to open device 'omapdrm'...failed trying to open device 'exynos'...done setting mode 1920x1080-60Hz@XR24 on connectors 43, crtc 41 testing 1920x1080@XR24 overlay plane 36 ^C [1]+ Stopped ../modetest -s 43:1920x1080 -P41:1920x1080 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 177400000: 0 0 0 0 6 1089830 266000000: 0 0 4 0 0 394620 * 532000000: 0 1 2 4 0 40520 Total transition : 19 root@target:~/devfreq# dmesg|tail [ 1552.161498] devfreq-event event2: nocp@10ca1800 (event: 498005/2128000) 60ms 23% 0x01c7f020 [ 1552.161528] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 60ms 0% 0x00000000 [ 1552.221416] devfreq-event event0: nocp@10ca1000 (event: 513190/2128000) 60ms 24% 0x01d5d710 [ 1552.221486] devfreq-event event1: nocp@10ca1400 (event: 0/2128000) 60ms 0% 0x00000000 [ 1552.221552] devfreq-event event2: nocp@10ca1800 (event: 508518/2128000) 60ms 23% 0x01d18ff0 [ 1552.221616] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 60ms 0% 0x00000000 [ 1552.281311] devfreq-event event0: nocp@10ca1000 (event: 505519/2128000) 60ms 23% 0x01ced138 [ 1552.281336] devfreq-event event1: nocp@10ca1400 (event: 0/2128000) 60ms 0% 0x00000000 [ 1552.281358] devfreq-event event2: nocp@10ca1800 (event: 499471/2128000) 60ms 23% 0x01c947b4 [ 1552.281380] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 60ms 0% 0x00000000 root@target:~/devfreq# dmesg|tail [ 1557.951773] devfreq-event event2: nocp@10ca1800 (event: 510726/2128000) 60ms 24% 0x01d39584 [ 1557.951851] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 60ms 0% 0x00000000 [ 1558.011229] devfreq-event event0: nocp@10ca1000 (event: 502846/2128000) 60ms 23% 0x01cc5eac [ 1558.011261] devfreq-event event1: nocp@10ca1400 (event: 0/2128000) 60ms 0% 0x00000000 [ 1558.011291] devfreq-event event2: nocp@10ca1800 (event: 497245/2128000) 60ms 23% 0x01c73dfc [ 1558.011320] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 60ms 0% 0x00000000 [ 1558.081269] devfreq-event event0: nocp@10ca1000 (event: 511612/2128000) 70ms 24% 0x02227618 [ 1558.081300] devfreq-event event1: nocp@10ca1400 (event: 0/2128000) 70ms 0% 0x00000000 [ 1558.081328] devfreq-event event2: nocp@10ca1800 (event: 506381/2128000) 70ms 23% 0x021cdfa0 [ 1558.081355] devfreq-event event3: nocp@10ca1c00 (event: 0/2128000) 70ms 0% 0x00000000 root@target:~/devfreq# fg %1 ../modetest -s 43:1920x1080 -P41:1920x1080 root@target:~/devfreq# dmesg|tail [ 1568.641483] devfreq-event event2: nocp@10ca1800 (event: 257123/709600) 60ms 36% 0x00eb675c [ 1568.641533] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1568.701434] devfreq-event event0: nocp@10ca1000 (event: 262797/709600) 60ms 37% 0x00f09930 [ 1568.701479] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1568.701522] devfreq-event event2: nocp@10ca1800 (event: 257838/709600) 60ms 36% 0x00ec0ef0 [ 1568.701565] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 [ 1568.761201] devfreq-event event0: nocp@10ca1000 (event: 258960/709600) 60ms 36% 0x00ed15e0 [ 1568.761220] devfreq-event event1: nocp@10ca1400 (event: 0/709600) 60ms 0% 0x00000000 [ 1568.761236] devfreq-event event2: nocp@10ca1800 (event: 253698/709600) 60ms 35% 0x00e844a8 [ 1568.761253] devfreq-event event3: nocp@10ca1c00 (event: 0/709600) 60ms 0% 0x00000000 root@target:~/devfreq# cat /sys/class/devfreq/devfreq2/trans_stat From : To : 88700000 133000000 177400000 266000000 532000000 time(ms) 88700000: 0 0 0 0 1 19630 133000000: 0 0 0 0 1 90 * 177400000: 0 0 0 0 6 1094030 266000000: 0 0 4 0 0 394620 532000000: 0 1 3 4 0 57630 Total transition : 20 --- After appling proposed patches devfreq changes wcore frequencies according to bus load. Kamil Konieczny (3): PM / devfreq: exynos-nocp: fix debug print type PM / devfreq: exynos-bus: prepare for change in load calc in exynos-nocp PM / devfreq: exynos-nocp: change load and total calculations drivers/devfreq/event/exynos-nocp.c | 61 ++++++++++++----------------- drivers/devfreq/exynos-bus.c | 21 +++++++++- include/linux/devfreq-event.h | 4 ++ 3 files changed, 48 insertions(+), 38 deletions(-) -- 2.25.0