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Srinivas Pandruvada authored
The maximum turbo P-State used by the intel_pstate driver may be limited by ACPI _PSS table entry 0. After commit 9522a2ff (cpufreq: intel_pstate: Enforce _PPC limits), the maximum performance on servers will be capped by the _PSS table entry 0 by default. Even though that is formally correct, it may lead to preformance regressions in some cases. Namely, if the _PSS table entry 0 is not the maximum turbo P-State, performance measured after commit 9522a2ff will not match the performance measured before that commit on the same system. For this reason, modify the code to always use the maximum turbo frequency as the one that corresponds to _PSS table entry 0 if turbo is enabled in the BIOS. This way, the performance levels from before commit 9522a2ff will be restored on the affected systems. Fixes: 9522a2ff (cpufreq: intel_pstate: Enforce _PPC limits) Suggested-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by:
Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> [ rjw : Changelog ] Signed-off-by:
Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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