The following commit has been merged into the smp/core branch of tip: Commit-ID: 2de7fd26d90729c4e3430f9924b199dea810a9bc Gitweb: https://git.kernel.org/tip/2de7fd26d90729c4e3430f9924b199dea810a9bc Author: Thomas Gleixner <tglx@xxxxxxxxxxxxx> AuthorDate: Fri, 12 May 2023 23:07:24 +02:00 Committer: Peter Zijlstra <peterz@xxxxxxxxxxxxx> CommitterDate: Mon, 15 May 2023 13:44:54 +02:00 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 <tglx@xxxxxxxxxxxxx> Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Tested-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> Tested-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx> Tested-by: Helge Deller <deller@xxxxxx> # parisc Tested-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> # Steam Deck Link: https://lore.kernel.org/r/20230512205256.369512093@xxxxxxxxxxxxx --- arch/x86/xen/smp_pv.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/arch/x86/xen/smp_pv.c b/arch/x86/xen/smp_pv.c index a6f9128..be40927 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; }
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