Commit 77360225 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'sched-urgent-2021-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull scheduler fix from Thomas Gleixner:
 "A single fix for the x86 scheduler topology:

  Using cluster topology on hybrid CPUs, e.g. Alder Lake, biases the
  scheduler towards the ATOM cluster as that has more total capacity.
  Use selection based on CPU priority instead"

* tag 'sched-urgent-2021-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched,x86: Don't use cluster topology for x86 hybrid CPUs
parents 0f3d41e8 cabdc3a8

arch/x86/kernel/smpboot.c

+14 −0
Original line number Original line Diff line number Diff line
@@ -579,6 +579,17 @@ static struct sched_domain_topology_level x86_numa_in_package_topology[] = { 
	{ NULL, },

	{ NULL, },

};

};





static struct sched_domain_topology_level x86_hybrid_topology[] = {

#ifdef CONFIG_SCHED_SMT

	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },

#endif

#ifdef CONFIG_SCHED_MC

	{ cpu_coregroup_mask, x86_core_flags, SD_INIT_NAME(MC) },

#endif

	{ cpu_cpu_mask, SD_INIT_NAME(DIE) },

	{ NULL, },

};



static struct sched_domain_topology_level x86_topology[] = {

static struct sched_domain_topology_level x86_topology[] = {

#ifdef CONFIG_SCHED_SMT

#ifdef CONFIG_SCHED_SMT

	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },

	{ cpu_smt_mask, x86_smt_flags, SD_INIT_NAME(SMT) },
@@ -1469,8 +1480,11 @@ void __init native_smp_cpus_done(unsigned int max_cpus) 




	calculate_max_logical_packages();

	calculate_max_logical_packages();





	/* XXX for now assume numa-in-package and hybrid don't overlap */

	if (x86_has_numa_in_package)

	if (x86_has_numa_in_package)

		set_sched_topology(x86_numa_in_package_topology);

		set_sched_topology(x86_numa_in_package_topology);

	if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))

		set_sched_topology(x86_hybrid_topology);





	nmi_selftest();

	nmi_selftest();

	impress_friends();

	impress_friends();