Commit f0d73394 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge Committed by Jeremy Fitzhardinge
Browse files

xen: yield to IPI target if necessary 



When sending a call-function IPI to a vcpu, yield if the vcpu isn't
running.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy@xensource.com>
parent d626a1f1

arch/x86/xen/smp.c

+10 −4
Original line number Diff line number Diff line
@@ -360,7 +360,8 @@ int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *), 
			       void *info, int wait)

{

	struct call_data_struct data;

	int cpus;

	int cpus, cpu;

	bool yield;



	/* Holding any lock stops cpus from going down. */

	spin_lock(&call_lock);
@@ -389,8 +390,13 @@ int xen_smp_call_function_mask(cpumask_t mask, void (*func)(void *), 
	/* Send a message to other CPUs and wait for them to respond */

	xen_send_IPI_mask(mask, XEN_CALL_FUNCTION_VECTOR);



	/* Make sure other vcpus get a chance to run.

	   XXX too severe?  Maybe we should check the other CPU's states? */

	/* Make sure other vcpus get a chance to run if they need to. */

	yield = false;

	for_each_cpu_mask(cpu, mask)

		if (xen_vcpu_stolen(cpu))

			yield = true;



	if (yield)

		HYPERVISOR_sched_op(SCHEDOP_yield, 0);



	/* Wait for response */

arch/x86/xen/time.c

+6 −0
Original line number Diff line number Diff line
@@ -105,6 +105,12 @@ static void get_runstate_snapshot(struct vcpu_runstate_info *res) 
	} while (get64(&state->state_entry_time) != state_time);

}



/* return true when a vcpu could run but has no real cpu to run on */

bool xen_vcpu_stolen(int vcpu)

{

	return per_cpu(runstate, vcpu).state == RUNSTATE_runnable;

}



static void setup_runstate_info(int cpu)

{

	struct vcpu_register_runstate_memory_area area;

arch/x86/xen/xen-ops.h

+2 −0
Original line number Diff line number Diff line
@@ -27,6 +27,8 @@ unsigned long xen_get_wallclock(void); 
int xen_set_wallclock(unsigned long time);

unsigned long long xen_sched_clock(void);



bool xen_vcpu_stolen(int vcpu);



void xen_mark_init_mm_pinned(void);



void __init xen_fill_possible_map(void);