Re: [patch 1/2] test: add wait parameter to on_cpu

[Avi Kivity <avi@redhat.com>]

On 09/28/2009 01:22 PM, Marcelo Tosatti wrote:
> To determine whether to wait for IPI to finish on remote cpu.
>
> Signed-off-by: Marcelo Tosatti<mtosatti@redhat.com>
>
> Index: qemu-kvm/kvm/user/test/lib/x86/smp.c
> ===================================================================
> --- qemu-kvm.orig/kvm/user/test/lib/x86/smp.c
> +++ qemu-kvm/kvm/user/test/lib/x86/smp.c
> @@ -82,7 +82,7 @@ static void setup_smp_id(void *data)
>       asm ("mov %0, %%gs:0" : : "r"(apic_id()) : "memory");
>   }
>
> -void on_cpu(int cpu, void (*function)(void *data), void *data)
> +void on_cpu(int cpu, void (*function)(void *data), void *data, int wait)
>   {
>       spin_lock(&ipi_lock);
>       if (cpu == smp_id())
> @@ -93,9 +93,11 @@ void on_cpu(int cpu, void (*function)(vo
>   	apic_icr_write(APIC_INT_ASSERT | APIC_DEST_PHYSICAL | APIC_DM_FIXED
>                          | IPI_VECTOR,
>                          cpu);
> -	while (!ipi_done)
> -	    ;
> -	ipi_done = 0;
> +	if (wait) {
> +		while (!ipi_done)
> +		    ;
> +		ipi_done = 0;
> +	}
>       }
>       spin_unlock(&ipi_lock);
>   }
> @@ -109,6 +111,6 @@ void smp_init(void)
>
>       setup_smp_id(0);
>       for (i = 1; i<  cpu_count(); ++i)
> -        on_cpu(i, setup_smp_id, 0);
> +        on_cpu(i, setup_smp_id, 0, 1);
>
>   }
> Index: qemu-kvm/kvm/user/test/lib/x86/smp.h
> ===================================================================
> --- qemu-kvm.orig/kvm/user/test/lib/x86/smp.h
> +++ qemu-kvm/kvm/user/test/lib/x86/smp.h
> @@ -9,7 +9,7 @@ void smp_init(void);
>
>   int cpu_count(void);
>   int smp_id(void);
> -void on_cpu(int cpu, void (*function)(void *data), void *data);
> +void on_cpu(int cpu, void (*function)(void *data), void *data, int wait);
>   void spin_lock(struct spinlock *lock);
>   void spin_unlock(struct spinlock *lock);
>
> Index: qemu-kvm/kvm/user/test/x86/smptest.c
> ===================================================================
> --- qemu-kvm.orig/kvm/user/test/x86/smptest.c
> +++ qemu-kvm/kvm/user/test/x86/smptest.c
> @@ -20,6 +20,6 @@ int main()
>       ncpus = cpu_count();
>       printf("found %d cpus\n", ncpus);
>       for (i = 0; i<  ncpus; ++i)
> -	on_cpu(i, ipi_test, (void *)(long)i);
> +	on_cpu(i, ipi_test, (void *)(long)i, 1);
>       return 0;
>   }
> Index: qemu-kvm/kvm/user/test/x86/vmexit.c
> ===================================================================
> --- qemu-kvm.orig/kvm/user/test/x86/vmexit.c
> +++ qemu-kvm/kvm/user/test/x86/vmexit.c
> @@ -63,14 +63,14 @@ static void nop(void *junk)
>
>   static void ipi(void)
>   {
> -	on_cpu(1, nop, 0);
> +	on_cpu(1, nop, 0, 1);
>   }
>
>   static void ipi_halt(void)
>   {
>   	unsigned long long t;
>
> -	on_cpu(1, nop, 0);
> +	on_cpu(1, nop, 0, 1);
>   	t = rdtsc() + 2000;
>   	while (rdtsc()<  t)
>   		;
>
>    

Boolean parameters are unreadable at the call site.  I'd much prefer a 
new API (on_cpu_async(), with on_cpu_join() to wait for completion).

-- 
error compiling committee.c: too many arguments to function