Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751720AbaJPQqP (ORCPT ); Thu, 16 Oct 2014 12:46:15 -0400 Received: from aserp1040.oracle.com ([141.146.126.69]:23203 "EHLO aserp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751293AbaJPQqO (ORCPT ); Thu, 16 Oct 2014 12:46:14 -0400 From: Boris Ostrovsky To: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, konrad.wilk@oracle.com, david.vrabel@citrix.com Cc: tianyu.lan@intel.com, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org, boris.ostrovsky@oracle.com Subject: [PATCH v2] xen/smp: Use die_complete completion when taking CPU down Date: Thu, 16 Oct 2014 12:47:26 -0400 Message-Id: <1413478046-4987-1-git-send-email-boris.ostrovsky@oracle.com> X-Mailer: git-send-email 1.8.1.4 X-Source-IP: ucsinet21.oracle.com [156.151.31.93] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit 2ed53c0d6cc9 ("x86/smpboot: Speed up suspend/resume by avoiding 100ms sleep for CPU offline during S3") introduced completions to CPU offlining process. These completions are not initialized on Xen kernels causing a panic in play_dead_common(). Move handling of die_complete into common routines to make them available to Xen guests. (Also, while at it, move these routines as well as die_complete under ifdef CONFIG_HOTPLUG_CPU) Signed-off-by: Boris Ostrovsky --- v2: Keep die_complete private to smpboot.c arch/x86/include/asm/smp.h | 5 ++++- arch/x86/kernel/smpboot.c | 13 +++++++++++-- arch/x86/xen/smp.c | 3 +++ 3 files changed, 18 insertions(+), 3 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 8cd27e0..a78c509 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -149,7 +149,11 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) smp_ops.send_call_func_ipi(mask); } +#ifdef CONFIG_HOTPLUG_CPU void cpu_disable_common(void); +void cpu_die_common(unsigned int cpu); +void play_dead_common(void); +#endif void native_smp_prepare_boot_cpu(void); void native_smp_prepare_cpus(unsigned int max_cpus); void native_smp_cpus_done(unsigned int max_cpus); @@ -157,7 +161,6 @@ int native_cpu_up(unsigned int cpunum, struct task_struct *tidle); int native_cpu_disable(void); void native_cpu_die(unsigned int cpu); void native_play_dead(void); -void play_dead_common(void); void wbinvd_on_cpu(int cpu); int wbinvd_on_all_cpus(void); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 2d5200e..6fe0fc1 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -102,7 +102,9 @@ DEFINE_PER_CPU_READ_MOSTLY(cpumask_var_t, cpu_llc_shared_map); DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info); EXPORT_PER_CPU_SYMBOL(cpu_info); +#ifdef CONFIG_HOTPLUG_CPU static DEFINE_PER_CPU(struct completion, die_complete); +#endif atomic_t init_deasserted; @@ -1309,6 +1311,8 @@ void cpu_disable_common(void) { int cpu = smp_processor_id(); + init_completion(&per_cpu(die_complete, smp_processor_id())); + remove_siblinginfo(cpu); /* It's now safe to remove this processor from the online map */ @@ -1327,16 +1331,21 @@ int native_cpu_disable(void) return ret; clear_local_APIC(); - init_completion(&per_cpu(die_complete, smp_processor_id())); cpu_disable_common(); return 0; } +void cpu_die_common(unsigned int cpu) +{ + wait_for_completion_timeout(&per_cpu(die_complete, cpu), HZ); +} + void native_cpu_die(unsigned int cpu) { /* We don't do anything here: idle task is faking death itself. */ - wait_for_completion_timeout(&per_cpu(die_complete, cpu), HZ); + + cpu_die_common(cpu); /* They ack this in play_dead() by setting CPU_DEAD */ if (per_cpu(cpu_state, cpu) == CPU_DEAD) { diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c index 8650cdb..4c071ae 100644 --- a/arch/x86/xen/smp.c +++ b/arch/x86/xen/smp.c @@ -510,6 +510,9 @@ static void xen_cpu_die(unsigned int cpu) current->state = TASK_UNINTERRUPTIBLE; schedule_timeout(HZ/10); } + + cpu_die_common(cpu); + xen_smp_intr_free(cpu); xen_uninit_lock_cpu(cpu); xen_teardown_timer(cpu); -- 1.8.1.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/