Commit dd787ae4 authored by Leo Yan's avatar Leo Yan Committed by Arnaldo Carvalho de Melo
Browse files

perf kvm: Use subtraction for comparison metrics 



Currently the metrics comparison uses greater operator (>), it returns
the boolean value (0 or 1).

This patch changes to use subtraction as comparison result, which can
be used by histograms sorting.  Since the subtraction result is u64
type, we change key_cmp_fun's return type to int64_t to avoid overflow.

Signed-off-by: default avatarLeo Yan <leo.yan@linaro.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230315145112.186603-2-leo.yan@linaro.org


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent f098376d

tools/perf/builtin-kvm.c

+3 −3
Original line number Diff line number Diff line
@@ -64,10 +64,10 @@ static u64 get_event_ ##func(struct kvm_event *event, int vcpu) \ 


#define COMPARE_EVENT_KEY(func, field)					\

GET_EVENT_KEY(func, field)						\

static int cmp_event_ ## func(struct kvm_event *one,			\

static int64_t cmp_event_ ## func(struct kvm_event *one,		\

			      struct kvm_event *two, int vcpu)		\

{									\

	return get_event_ ##func(one, vcpu) >				\

	return get_event_ ##func(one, vcpu) -				\

	       get_event_ ##func(two, vcpu);				\

}
@@ -525,7 +525,7 @@ static void insert_to_result(struct rb_root *result, struct kvm_event *event, 
		p = container_of(*rb, struct kvm_event, rb);

		parent = *rb;



		if (bigger(event, p, vcpu))

		if (bigger(event, p, vcpu) > 0)

			rb = &(*rb)->rb_left;

		else

			rb = &(*rb)->rb_right;

tools/perf/util/kvm-stat.h

+1 −1
Original line number Diff line number Diff line
@@ -40,7 +40,7 @@ struct kvm_event { 
	struct kvm_event_stats *vcpu;

};



typedef int (*key_cmp_fun)(struct kvm_event*, struct kvm_event*, int);

typedef int64_t (*key_cmp_fun)(struct kvm_event*, struct kvm_event*, int);



struct kvm_event_key {

	const char *name;