[Intel][6.6] Backport AET support for Intel platforms

[x56Jason]

Description

This is backport upstream AET (Application Energy Telemetry) for Intel platforms.

The backport consists of 2 parts, the kernel part and the resctrl kernel selftest.

Test

• AET test on CWF platform (Currently no AET-supported DMR platform yet)

$ cat loop.c
int main(void)
{
        int i;
        while (1) {
                i++;
        }

        return 0;
}

$ uname -a
Linux CS17CA101IS1501 6.6.122-ve-aet+ #1 SMP PREEMPT_DYNAMIC Mon Jun 29 21:56:37 EDT 2026 x86_64 x86_64 x86_64 GNU/Linux
$ sudo su
[root@CS17CA101IS1501 zengz]# mount -t resctrl none /sys/fs/resctrl
[root@CS17CA101IS1501 zengz]# dmesg|grep resctrl
[   21.450542] resctrl: L3 allocation detected
[   21.465446] resctrl: L2 allocation detected
[   21.473634] resctrl: MB allocation detected
[   21.481753] resctrl: L3 monitoring detected
[  247.191165] resctrl: PERF_PKG energy:0x26696143 monitoring detected
[  247.199153] resctrl: PERF_PKG perf:0x26557651 monitoring not enabled due to insufficient RMIDs
[root@CS17CA101IS1501 zengz]# tree /sys/fs/resctrl/mon_data/
/sys/fs/resctrl/mon_data/
├── mon_L3_00
│   ├── llc_occupancy
│   ├── mbm_local_bytes
│   └── mbm_total_bytes
└── mon_PERF_PKG_00
    ├── activity
    └── core_energy

2 directories, 5 files
[root@CS17CA101IS1501 zengz]# mkdir /sys/fs/resctrl/aet_example
[root@CS17CA101IS1501 zengz]# ps -ef|grep loop
zengz       4964    4922 95 22:06 pts/3    00:00:09 ./loop
root        4966    4860  0 22:06 pts/2    00:00:00 grep --color=auto loop
[root@CS17CA101IS1501 zengz]# echo 4964 > /sys/fs/resctrl/aet_example/tasks
[root@CS17CA101IS1501 zengz]# cat /sys/fs/resctrl/aet_example/tasks
4964
[root@CS17CA101IS1501 zengz]# dir=/sys/fs/resctrl/aet_example/mon_data/mon_PERF_PKG_00
[root@CS17CA101IS1501 zengz]# cat $dir/core_energy; sleep 10; cat $dir/core_energy
1271819.896427
1271825.179474
[root@CS17CA101IS1501 zengz]#

• RDT kernel selftest on GNR platform

# tools/testing/selftests/resctrl/resctrl_tests
TAP version 13
# Pass: Check kernel supports resctrl filesystem
# Pass: Check resctrl mountpoint "/sys/fs/resctrl" exists
# resctrl filesystem not mounted
# dmesg: [   41.981606] resctrl: Sub-NUMA Cluster mode detected with 2 nodes per L3 cache
# dmesg: [   42.055874] resctrl: L3 allocation detected
# dmesg: [   42.064198] resctrl: L2 allocation detected
# dmesg: [   42.072427] resctrl: MB allocation detected
# dmesg: [   42.080589] resctrl: L3 monitoring detected
1..6
# SNC-2 mode discovered.
# Starting MBM test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Writing benchmark parameters to resctrl FS
# Benchmark PID: 5090
# Write schema "MB:0=100" to resctrl FS
# Checking for pass/fail
# Pass: Check MBM diff within 15%
# avg_diff_per: 2%
# Span (MB): 576
# avg_bw_imc: 9050
# avg_bw_resc: 8780
ok 1 MBM: test
# Starting MBA test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Writing benchmark parameters to resctrl FS
# Benchmark PID: 5093
# Write schema "MB:0=10" to resctrl FS
# Write schema "MB:0=20" to resctrl FS
# Write schema "MB:0=30" to resctrl FS
# Write schema "MB:0=40" to resctrl FS
# Write schema "MB:0=50" to resctrl FS
# Write schema "MB:0=60" to resctrl FS
# Write schema "MB:0=70" to resctrl FS
# Write schema "MB:0=80" to resctrl FS
# Write schema "MB:0=90" to resctrl FS
# Write schema "MB:0=100" to resctrl FS
# Results are displayed in (MB)
# Bandwidth below threshold (2500 MiB). Dropping results from MBA schemata 10.
# Bandwidth below threshold (2500 MiB). Dropping results from MBA schemata 20.
# Bandwidth below threshold (2500 MiB). Dropping results from MBA schemata 30.
# Bandwidth below threshold (2500 MiB). Dropping results from MBA schemata 40.
# Bandwidth below threshold (2500 MiB). Dropping results from MBA schemata 50.
# Pass: Check MBA diff within 15% for schemata 60
# avg_diff_per: 3%
# avg_bw_imc: 4292
# avg_bw_resc: 4134
# Pass: Check MBA diff within 15% for schemata 70
# avg_diff_per: 4%
# avg_bw_imc: 5636
# avg_bw_resc: 5406
# Pass: Check MBA diff within 15% for schemata 80
# avg_diff_per: 4%
# avg_bw_imc: 7055
# avg_bw_resc: 6742
# Pass: Check MBA diff within 15% for schemata 90
# avg_diff_per: 3%
# avg_bw_imc: 8772
# avg_bw_resc: 8465
# Pass: Check MBA diff within 15% for schemata 100
# avg_diff_per: 3%
# avg_bw_imc: 9081
# avg_bw_resc: 8808
# Pass: Check schemata change using MBA
ok 2 MBA: test
# Starting CMT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Cache size :150994944
# Writing benchmark parameters to resctrl FS
# Write schema "L3:0=ffe0" to resctrl FS
# Write schema "L3:0=1f" to resctrl FS
# Write schema "L2:1=0x1" to resctrl FS
# Benchmark PID: 5118
# Checking for pass/fail
# Pass: Check cache miss rate within 15%
# Percent diff=0
# Number of bits: 5
# Average LLC val: 47185920
# Cache span (bytes): 47185920
ok 3 CMT: test
# Starting L3_CAT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Cache size :150994944
# Writing benchmark parameters to resctrl FS
# Write schema "L2:1=0x1" to resctrl FS
# Write schema "L3:0=3f80" to resctrl FS
# Write schema "L3:0=7e" to resctrl FS
# Write schema "L3:0=3fe0" to resctrl FS
# Write schema "L3:0=1e" to resctrl FS
# Write schema "L3:0=3ff8" to resctrl FS
# Write schema "L3:0=6" to resctrl FS
# Checking for pass/fail
# Number of bits: 6
# Average LLC val: 571561
# Cache span (lines): 884736
# Pass: Check cache miss rate increased
# Number of bits: 4
# Average LLC val: 1158953
# Cache span (lines): 589824
# Pass: Check cache miss rate increased
# Number of bits: 2
# Average LLC val: 1756185
# Cache span (lines): 294912
ok 4 L3_CAT: test
# Starting L3_NONCONT_CAT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Write schema "L3:0=ff" to resctrl FS
# Write schema "L3:0=fc3f" to resctrl FS
ok 5 L3_NONCONT_CAT: test
# Starting L2_NONCONT_CAT test ...
# Mounting resctrl to "/sys/fs/resctrl"
# Write schema "L2:1=ff" to resctrl FS
# Write schema "L2:1=fc3f" to resctrl FS # write() failed : Invalid argument
# Non-contiguous CBMs not supported and write of non-contiguous CBM failed as expected
ok 6 L2_NONCONT_CAT: test
# Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0