Diffstat (limited to 'arch/x86/kernel/apic/vector.c')
1 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kernel/apic/vector.c b/arch/x86/kernel/apic/vector.c
index 2c5676b0a6e7..48293d15f1e1 100644
@@ -838,13 +838,15 @@ static void free_moved_vector(struct apic_chip_data *apicd)
bool managed = apicd->is_managed;
- * This should never happen. Managed interrupts are not
- * migrated except on CPU down, which does not involve the
- * cleanup vector. But try to keep the accounting correct
- * nevertheless.
+ * Managed interrupts are usually not migrated away
+ * from an online CPU, but CPU isolation 'managed_irq'
+ * can make that happen.
+ * 1) Activation does not take the isolation into account
+ * to keep the code simple
+ * 2) Migration away from an isolated CPU can happen when
+ * a non-isolated CPU which is in the calculated
+ * affinity mask comes online.
trace_vector_free_moved(apicd->irq, cpu, vector, managed);
irq_matrix_free(vector_matrix, cpu, vector, managed);
per_cpu(vector_irq, cpu)[vector] = VECTOR_UNUSED;