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Commit 54279552 authored by Boris Ostrovsky's avatar Boris Ostrovsky Committed by Ingo Molnar
Browse files

x86/core, x86/xen/smp: Use 'die_complete' completion when taking CPU down 



Commit 2ed53c0d ("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: default avatarBoris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Cc: tianyu.lan@intel.com
Cc: konrad.wilk@oracle.com
Cc: xen-devel@lists.xenproject.org
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/1414770572-7950-1-git-send-email-boris.ostrovsky@oracle.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent e6023367

arch/x86/include/asm/smp.h

+1 −0
Original line number Diff line number Diff line
@@ -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);

arch/x86/kernel/smpboot.c

+11 −4
Original line number Diff line number Diff line
@@ -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) {

arch/x86/xen/smp.c

+3 −0
Original line number Diff line number Diff line
@@ -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);