[Bug 220117] New: cpufreq performance governor doesn't correctly apply in combination with isolcpus

[bugzilla-daemon@kernel.org]

https://bugzilla.kernel.org/show_bug.cgi?id=220117

            Bug ID: 220117
           Summary: cpufreq performance governor doesn't correctly apply
                    in combination with isolcpus
           Product: Power Management
           Version: 2.5
          Hardware: Intel
                OS: Linux
            Status: NEW
          Severity: normal
          Priority: P3
         Component: cpufreq
          Assignee: linux-pm@vger.kernel.org
          Reporter: robbert.proost@vitestro.com
        Regression: No

During testing on my setup with kernel 6.6.69 I have found that even though the
cpufreq uses the performance governor, it doesn't seem to correctly apply on
CPUs that are isolated using `isolcpus`.

In my setup if have isolated core 2 and 3 set
CONFIG_CPU_FREQ_DEFAULT_GOV_PERFORMANCE in my kernel configuration to 'Y'.
When verifying the used governor with 'cat
/sys/devices/system/cpu/cpu2/cpufreq/scaling_governor' it correctly outputs
'performance'.

However, when running 'cat /proc/cpuinfo' the clock frequency of the isolated
CPUs is 800 MHz instead of the expected 3000 MHz. For the not isolated CPUs it
does correctly show 3000 MHz. Changing
'/sys/devices/system/cpu/cpuX/cpufreq/scaling_min_freq' to 3000 MHz does change
the clock frequency to 3000 MHz, but that shouldn't be needed.

Kernel bootline: console=tty console=ttyS0,115200 acpi_enforce_resources=lax
panic=1 earlyprintk isolcpus=2,3 rootwait

-- 
You may reply to this email to add a comment.

You are receiving this mail because:
You are the assignee for the bug.