diff mbox series

[V4,17/37] x86/xen/smp_pv: Remove wait for CPU online

Message ID 20230512205256.369512093@linutronix.de (mailing list archive)
State Handled Elsewhere
Headers show
Series [V4,01/37] x86/smpboot: Cleanup topology_phys_to_logical_pkg()/die() | expand

Checks

Context Check Description
conchuod/cover_letter warning Series does not have a cover letter
conchuod/tree_selection success Guessed tree name to be for-next at HEAD ac9a78681b92
conchuod/fixes_present success Fixes tag not required for -next series
conchuod/maintainers_pattern success MAINTAINERS pattern errors before the patch: 6 and now 6
conchuod/verify_signedoff success Signed-off-by tag matches author and committer
conchuod/kdoc success Errors and warnings before: 0 this patch: 0
conchuod/build_rv64_clang_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/module_param success Was 0 now: 0
conchuod/build_rv64_gcc_allmodconfig success Errors and warnings before: 8 this patch: 8
conchuod/build_rv32_defconfig success Build OK
conchuod/dtb_warn_rv64 success Errors and warnings before: 3 this patch: 3
conchuod/header_inline success No static functions without inline keyword in header files
conchuod/checkpatch warning WARNING: Do not crash the kernel unless it is absolutely unavoidable--use WARN_ON_ONCE() plus recovery code (if feasible) instead of BUG() or variants
conchuod/build_rv64_nommu_k210_defconfig success Build OK
conchuod/verify_fixes success No Fixes tag
conchuod/build_rv64_nommu_virt_defconfig success Build OK

Commit Message

Thomas Gleixner May 12, 2023, 9:07 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>
Tested-by: Michael Kelley <mikelley@microsoft.com>
---
 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;
 }