Commit 4f75bcc3 authored by Peter Xu's avatar Peter Xu Committed by Paolo Bonzini
Browse files

KVM: X86: Tune PLE Window tracepoint 



The PLE window tracepoint triggers even if the window is not changed,
and the wording can be a bit confusing too.  One example line:

  kvm_ple_window: vcpu 0: ple_window 4096 (shrink 4096)

It easily let people think of "the window now is 4096 which is
shrinked", but the truth is the value actually didn't change (4096).

Let's only dump this message if the value really changed, and we make
the message even simpler like:

  kvm_ple_window: vcpu 4 old 4096 new 8192 (growed)

Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Reviewed-by: default avatarSean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent c5c5d6fa

arch/x86/kvm/svm.c

+8 −8
Original line number Diff line number Diff line
@@ -1266,12 +1266,12 @@ static void grow_ple_window(struct kvm_vcpu *vcpu) 
							pause_filter_count_grow,

							pause_filter_count_max);



	if (control->pause_filter_count != old)

	if (control->pause_filter_count != old) {

		mark_dirty(svm->vmcb, VMCB_INTERCEPTS);



	trace_kvm_ple_window_grow(vcpu->vcpu_id,

		trace_kvm_ple_window_update(vcpu->vcpu_id,

					    control->pause_filter_count, old);

	}

}



static void shrink_ple_window(struct kvm_vcpu *vcpu)

{
@@ -1284,12 +1284,12 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu) 
						    pause_filter_count,

						    pause_filter_count_shrink,

						    pause_filter_count);

	if (control->pause_filter_count != old)

	if (control->pause_filter_count != old) {

		mark_dirty(svm->vmcb, VMCB_INTERCEPTS);



	trace_kvm_ple_window_shrink(vcpu->vcpu_id,

		trace_kvm_ple_window_update(vcpu->vcpu_id,

					    control->pause_filter_count, old);

	}

}



static __init int svm_hardware_setup(void)

{

arch/x86/kvm/trace.h

+6 −16
Original line number Diff line number Diff line
@@ -890,37 +890,27 @@ TRACE_EVENT(kvm_pml_full, 
	TP_printk("vcpu %d: PML full", __entry->vcpu_id)

);



TRACE_EVENT(kvm_ple_window,

	TP_PROTO(bool grow, unsigned int vcpu_id, unsigned int new,

		 unsigned int old),

	TP_ARGS(grow, vcpu_id, new, old),

TRACE_EVENT(kvm_ple_window_update,

	TP_PROTO(unsigned int vcpu_id, unsigned int new, unsigned int old),

	TP_ARGS(vcpu_id, new, old),



	TP_STRUCT__entry(

		__field(                bool,      grow         )

		__field(        unsigned int,   vcpu_id         )

		__field(        unsigned int,       new         )

		__field(        unsigned int,       old         )

	),



	TP_fast_assign(

		__entry->grow           = grow;

		__entry->vcpu_id        = vcpu_id;

		__entry->new            = new;

		__entry->old            = old;

	),



	TP_printk("vcpu %u: ple_window %u (%s %u)",

	          __entry->vcpu_id,

	          __entry->new,

	          __entry->grow ? "grow" : "shrink",

	          __entry->old)

	TP_printk("vcpu %u old %u new %u (%s)",

	          __entry->vcpu_id, __entry->old, __entry->new,

		  __entry->old < __entry->new ? "growed" : "shrinked")

);



#define trace_kvm_ple_window_grow(vcpu_id, new, old) \

	trace_kvm_ple_window(true, vcpu_id, new, old)

#define trace_kvm_ple_window_shrink(vcpu_id, new, old) \

	trace_kvm_ple_window(false, vcpu_id, new, old)



TRACE_EVENT(kvm_pvclock_update,

	TP_PROTO(unsigned int vcpu_id, struct pvclock_vcpu_time_info *pvclock),

	TP_ARGS(vcpu_id, pvclock),

arch/x86/kvm/vmx/vmx.c

+8 −6
Original line number Diff line number Diff line
@@ -5243,10 +5243,11 @@ static void grow_ple_window(struct kvm_vcpu *vcpu) 
					    ple_window_grow,

					    ple_window_max);



	if (vmx->ple_window != old)

	if (vmx->ple_window != old) {

		vmx->ple_window_dirty = true;



	trace_kvm_ple_window_grow(vcpu->vcpu_id, vmx->ple_window, old);

		trace_kvm_ple_window_update(vcpu->vcpu_id,

					    vmx->ple_window, old);

	}

}



static void shrink_ple_window(struct kvm_vcpu *vcpu)
@@ -5258,10 +5259,11 @@ static void shrink_ple_window(struct kvm_vcpu *vcpu) 
					      ple_window_shrink,

					      ple_window);



	if (vmx->ple_window != old)

	if (vmx->ple_window != old) {

		vmx->ple_window_dirty = true;



	trace_kvm_ple_window_shrink(vcpu->vcpu_id, vmx->ple_window, old);

		trace_kvm_ple_window_update(vcpu->vcpu_id,

					    vmx->ple_window, old);

	}

}



/*

arch/x86/kvm/x86.c

+1 −1
Original line number Diff line number Diff line
@@ -10098,7 +10098,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_invlpga); 
EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_skinit);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_nested_intercepts);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_write_tsc_offset);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_ple_window_update);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pml_full);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_pi_irte_update);

EXPORT_TRACEPOINT_SYMBOL_GPL(kvm_avic_unaccelerated_access);