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authorLinus Torvalds <torvalds@linux-foundation.org>2021-12-12 09:38:04 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2021-12-12 09:38:04 -0800
commit773602256a2ca73455b0baeae5737c4a9ed6ef49 (patch)
treecfb4ed5ba04a8d9fd28e1bc19644f8e70513c515 /arch
parent0f3d41e82d78bf521dfee4d6db1d247628dcf399 (diff)
parentcabdc3a8475b918e55744f43719b26a82dc8fa6b (diff)
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
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kernel/smpboot.c14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index ac2909f0cab3..617012f4619f 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -579,6 +579,17 @@ static struct sched_domain_topology_level x86_numa_in_package_topology[] = {
{ 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[] = {
#ifdef CONFIG_SCHED_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();
+ /* XXX for now assume numa-in-package and hybrid don't overlap */
if (x86_has_numa_in_package)
set_sched_topology(x86_numa_in_package_topology);
+ if (cpu_feature_enabled(X86_FEATURE_HYBRID_CPU))
+ set_sched_topology(x86_hybrid_topology);
nmi_selftest();
impress_friends();