diff mbox series

[V2,16/38] x86/xen/smp_pv: Remove wait for CPU online

Message ID 20230504185937.201611990@linutronix.de (mailing list archive)
State Superseded
Headers show
Series cpu/hotplug, x86: Reworked parallel CPU bringup | expand

Commit Message

Thomas Gleixner May 4, 2023, 7:02 p.m. UTC 
From: Thomas Gleixner <tglx@linutronix.de>

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 <tglx@linutronix.de>
Cc: Juergen Gross <jgross@suse.com>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: xen-devel@lists.xenproject.org

---
 arch/x86/xen/smp_pv.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)
---
diff mbox series

Patch

--- 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 cp
 
 	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;
 }