Re: [PATCHv2] trace "exit to userspace" event

[Gleb Natapov <gleb@redhat.com>]

On Sun, Oct 24, 2010 at 07:01:30PM +0200, Avi Kivity wrote:
>  On 10/24/2010 04:49 PM, Gleb Natapov wrote:
> >Add tracepoint for userspace exit.
> >
> >
> >+
> >+TRACE_EVENT(kvm_userspace_exit,
> >+	    TP_PROTO(__u32 reason, int errno),
> >+	    TP_ARGS(reason, errno),
> >+
> >+	TP_STRUCT__entry(
> >+		__field(	__u32,		reason		)
> >+		__field(	int,		errno		)
> >+	),
> >+
> >+	TP_fast_assign(
> >+		__entry->reason		= reason;
> >+		__entry->errno		= errno;
> 
> Shouldn't this be -errno?
> 
I check for __entry->errno < 0 below to see if exit was due to an error.

> >+	),
> >+
> >+	TP_printk("reason %s (%d)",
> >+		  __entry->errno<  0 ?
> >+		  (__entry->errno == -EINTR ? "restart" : "error") :
> >+		  __print_symbolic(__entry->reason, kvm_trace_exit_reason),
> >+		  __entry->errno<  0 ? -__entry->errno : __entry->reason)
> >+);
> >+
> >  #if defined(__KVM_HAVE_IOAPIC)
> >  TRACE_EVENT(kvm_set_irq,
> >  	TP_PROTO(unsigned int gsi, int level, int irq_source_id),
> >diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> >index 361ad1a..88c42ae 100644
> >--- a/virt/kvm/kvm_main.c
> >+++ b/virt/kvm/kvm_main.c
> >@@ -1537,6 +1537,7 @@ static long kvm_vcpu_ioctl(struct file *filp,
> >  		if (arg)
> >  			goto out;
> >  		r = kvm_arch_vcpu_ioctl_run(vcpu, vcpu->run);
> >+		trace_kvm_userspace_exit(vcpu->run->exit_reason, r);
> >  		break;
> 
> -- 
> error compiling committee.c: too many arguments to function

--
			Gleb.