From 54279552bd260532d90e7a59fbc931924bbb0f7b Mon Sep 17 00:00:00 2001 From: Boris Ostrovsky Date: Fri, 31 Oct 2014 11:49:32 -0400 Subject: [PATCH] x86/core, x86/xen/smp: Use 'die_complete' completion when taking CPU down 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. Signed-off-by: Boris Ostrovsky Reviewed-by: David Vrabel Cc: tianyu.lan@intel.com Cc: konrad.wilk@oracle.com Cc: xen-devel@lists.xenproject.org Cc: Linus Torvalds Link: http://lkml.kernel.org/r/1414770572-7950-1-git-send-email-boris.ostrovsky@oracle.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/smp.h | 1 + arch/x86/kernel/smpboot.c | 15 +++++++++++---- arch/x86/xen/smp.c | 3 +++ 3 files changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/x86/include/asm/smp.h b/arch/x86/include/asm/smp.h index 8cd27e08e23c..8cd1cc3bc835 100644 --- a/arch/x86/include/asm/smp.h +++ b/arch/x86/include/asm/smp.h @@ -150,6 +150,7 @@ static inline void arch_send_call_function_ipi_mask(const struct cpumask *mask) } void cpu_disable_common(void); +void cpu_die_common(unsigned int cpu); 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); diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c index 4d2128ac70bd..668d8f2a8781 100644 --- a/arch/x86/kernel/smpboot.c +++ b/arch/x86/kernel/smpboot.c @@ -1303,10 +1303,14 @@ static void __ref remove_cpu_from_maps(int cpu) numa_remove_cpu(cpu); } +static DEFINE_PER_CPU(struct completion, die_complete); + 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 */ @@ -1316,8 +1320,6 @@ void cpu_disable_common(void) fixup_irqs(); } -static DEFINE_PER_CPU(struct completion, die_complete); - int native_cpu_disable(void) { int ret; @@ -1327,16 +1329,21 @@ 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 8650cdb53209..4c071aeb8417 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);