From: Thomas Gleixner Date: Wed, 29 Mar 2023 14:11:28 +0000 (+0200) Subject: x86/xen/smp_pv: Remove wait for CPU online X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=a2ac3aefda991be03f1df960c9c8c7693872e51b;p=users%2Fdwmw2%2Flinux.git x86/xen/smp_pv: Remove wait for CPU online Now that the core code drops sparse_irq_lock after the idle thread synchronized, it's pointless to wait for the AP to mark itself online. Whether the control CPU runs in a wait loop or sleeps in the core code waiting for the online operation to complete makes no difference. Signed-off-by: Thomas Gleixner --- diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index a6f9128a40912..be40927667cf2 100644 --- a/arch/x86/xen/smp_pv.c +++ b/arch/x86/xen/smp_pv.c @@ -340,11 +340,11 @@ static int xen_pv_cpu_up(unsigned int cpu, struct task_struct *idle) xen_pmu_init(cpu); - rc = HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL); - BUG_ON(rc); - - while (cpu_report_state(cpu) != CPU_ONLINE) - HYPERVISOR_sched_op(SCHEDOP_yield, NULL); + /* + * Why is this a BUG? If the hypercall fails then everything can be + * rolled back, no? + */ + BUG_ON(HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL)); return 0; }