[Error!!!] when using cache-misses event on Zing

[rockingl]

Hi, it's appear to a error when i use Zing jdk.
the host 1 can run cache-misses event(jdk version):
java 17.0.8.1.101 2023-10-11 LTS Java Runtime Environment Zing23.08.100.0+1 (build 17.0.8.1.101+1-LTS) Zing 64-Bit Tiered VM Zing23.08.100.0+1 (build 17.0.8.1.101-zing_23.08.100.0-b1-product-linux-X86_64, mixed mode)

but the host 2 can't run cache-misses event(jdk version):
java 17.0.9 2023-11-16 LTS Java Runtime Environment Zing23.08.200.0+3 (build 17.0.9+8-LTS) Zing 64-Bit Tiered VM Zing23.08.200.0+3 (build 17.0.9-zing_23.08.200.0-b3-product-linux-X86_64, mixed mode)

the error is:
sh -c "/home/async-profiler/profiler.sh -d 30 -i 20ms -e cache-misses -t -o flamegraph -f /xxx.html 3675508" [WARN] Kernel symbols are unavailable due to restrictions. Try sysctl kernel.perf_event_paranoid=1 sysctl kernel.kptr_restrict=0 [WARN] perf_event_open for TID 3675508 failed: No such file or directory [WARN] perf_event_open for TID 3675509 failed: No such file or directory [WARN] perf_event_open for TID 3675528 failed: No such file or directory [WARN] perf_event_open for TID 3675530 failed: No such file or directory [WARN] perf_event_open for TID 3675531 failed: No such file or directory [WARN] perf_event_open for TID 3675532 failed: No such file or directory [WARN] perf_event_open for TID 3675533 failed: No such file or directory [WARN] perf_event_open for TID 3675534 failed: No such file or directory [WARN] perf_event_open for TID 3675535 failed: No such file or directory [WARN] perf_event_open for TID 3675536 failed: No such file or directory [WARN] perf_event_open for TID 3675537 failed: No such file or directory [WARN] perf_event_open for TID 3675538 failed: No such file or directory [WARN] perf_event_open for TID 3675539 failed: No such file or directory [WARN] perf_event_open for TID 3675540 failed: No such file or directory [WARN] perf_event_open for TID 3675541 failed: No such file or directory [WARN] perf_event_open for TID 3675542 failed: No such file or directory [WARN] perf_event_open for TID 3675543 failed: No such file or directory [WARN] perf_event_open for TID 3675544 failed: No such file or directory [WARN] perf_event_open for TID 3675545 failed: No such file or directory

when i set:
sysctl kernel.perf_event_paranoid=1
sysctl kernel.kptr_restrict=0

it's appear to:
[WARN] Kernel symbols are unavailable due to restrictions. Try sysctl kernel.perf_event_paranoid=1 sysctl kernel.kptr_restrict=0 message disappoint.

so, it's why. any help will be appreciate. thank you!

[apangin]

cache-misses event is provided by hardware performance counters. Virtualized systems often restrict access to these counters. For example, AWS instances (unless they run on a dedicated server) do not allow access to hardware performance counters, and therefore you cannot use these systems to profile events such as cache-misses.

Does CPU profiling (-e cpu) work on that host?

[rockingl]

cache-misses event is provided by hardware performance counters. Virtualized systems often restrict access to these counters. For example, AWS instances (unless they run on a dedicated server) do not allow access to hardware performance counters, and therefore you cannot use these systems to profile events such as cache-misses.

Does CPU profiling (-e cpu) work on that host?

Thanks! it's work fine in cpu、lock、alloc event. but cache-misses can't run.

[rockingl]

my host kern version:
-- Linux hostname 5.10.134-12.al8.x86_64 #1 SMP Tue Sep 6 14:59:57 CST 2022 x86_64 x86_64 x86_64 GNU/Linux

How can I check whether the virtual system is supported?

[apangin]

Run cpuid -1 and look for "Architecture Performance Monitoring Features" in the output.

If hardware perf counters are supported, the output will look like

   Architecture Performance Monitoring Features (0xa/eax):
      version ID                               = 0x2 (2)
      number of counters per logical processor = 0x4 (4)
      bit width of counter                     = 0x30 (48)
      length of EBX bit vector                 = 0x7 (7)
...
   Architecture Performance Monitoring Features (0xa/edx):
      number of fixed counters    = 0x3 (3)
      bit width of fixed counters = 0x30 (48)
      anythread deprecation       = false

If they are not supported, you will see zeros instead:

   Architecture Performance Monitoring Features (0xa/eax):
      version ID                               = 0x0 (0)
      number of counters per logical processor = 0x0 (0)
      bit width of counter                     = 0x0 (0)
      length of EBX bit vector                 = 0x0 (0)
...
   Architecture Performance Monitoring Features (0xa/edx):
      number of fixed counters    = 0x0 (0)
      bit width of fixed counters = 0x0 (0)

Alternatively, check dmesg for "Performance Events":

When supported:

[    0.577362] Performance Events: IvyBridge events, full-width counters, Intel PMU driver.
[    0.578189] ... version:                2
[    0.578556] ... bit width:              48
[    0.578932] ... generic registers:      4

When not supported:

[    0.067039] Performance Events: unsupported p6 CPU model 154 no PMU driver, software events only.

[rockingl]

Run cpuid -1 and look for "Architecture Performance Monitoring Features" in the output.

If hardware perf counters are supported, the output will look like

   Architecture Performance Monitoring Features (0xa/eax):
      version ID                               = 0x2 (2)
      number of counters per logical processor = 0x4 (4)
      bit width of counter                     = 0x30 (48)
      length of EBX bit vector                 = 0x7 (7)
...
   Architecture Performance Monitoring Features (0xa/edx):
      number of fixed counters    = 0x3 (3)
      bit width of fixed counters = 0x30 (48)
      anythread deprecation       = false

If they are not supported, you will see zeros instead:

   Architecture Performance Monitoring Features (0xa/eax):
      version ID                               = 0x0 (0)
      number of counters per logical processor = 0x0 (0)
      bit width of counter                     = 0x0 (0)
      length of EBX bit vector                 = 0x0 (0)
...
   Architecture Performance Monitoring Features (0xa/edx):
      number of fixed counters    = 0x0 (0)
      bit width of fixed counters = 0x0 (0)

Alternatively, check dmesg for "Performance Events":

When supported:

[    0.577362] Performance Events: IvyBridge events, full-width counters, Intel PMU driver.
[    0.578189] ... version:                2
[    0.578556] ... bit width:              48
[    0.578932] ... generic registers:      4

When not supported:

[    0.067039] Performance Events: unsupported p6 CPU model 154 no PMU driver, software events only.

i will check my host soon. thank you very much for your help！