Commit 046a5a95 authored by Ricardo Neri's avatar Ricardo Neri Committed by Peter Zijlstra
Browse files

x86/sched/itmt: Give all SMT siblings of a core the same priority 



X86 does not have the SD_ASYM_PACKING flag in the SMT domain. The scheduler
knows how to handle SMT and non-SMT cores of different priority. There is
no reason for SMT siblings of a core to have different priorities.

Signed-off-by: default avatarRicardo Neri <ricardo.neri-calderon@linux.intel.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: default avatarLen Brown <len.brown@intel.com>
Tested-by: default avatarZhang Rui <rui.zhang@intel.com>
Link: https://lore.kernel.org/r/20230406203148.19182-12-ricardo.neri-calderon@linux.intel.com
parent 995998eb

arch/x86/kernel/itmt.c

+5 −18
Original line number Diff line number Diff line
@@ -165,32 +165,19 @@ int arch_asym_cpu_priority(int cpu) 


/**

 * sched_set_itmt_core_prio() - Set CPU priority based on ITMT

 * @prio:	Priority of cpu core

 * @core_cpu:	The cpu number associated with the core

 * @prio:	Priority of @cpu

 * @cpu:	The CPU number

 *

 * The pstate driver will find out the max boost frequency

 * and call this function to set a priority proportional

 * to the max boost frequency. CPU with higher boost

 * to the max boost frequency. CPUs with higher boost

 * frequency will receive higher priority.

 *

 * No need to rebuild sched domain after updating

 * the CPU priorities. The sched domains have no

 * dependency on CPU priorities.

 */

void sched_set_itmt_core_prio(int prio, int core_cpu)

void sched_set_itmt_core_prio(int prio, int cpu)

{

	int cpu, i = 1;



	for_each_cpu(cpu, topology_sibling_cpumask(core_cpu)) {

		int smt_prio;



		/*

		 * Ensure that the siblings are moved to the end

		 * of the priority chain and only used when

		 * all other high priority cpus are out of capacity.

		 */

		smt_prio = prio * smp_num_siblings / (i * i);

		per_cpu(sched_core_priority, cpu) = smt_prio;

		i++;

	}

	per_cpu(sched_core_priority, cpu) = prio;

}