make strategy evaluation return "long double"

this allows us to compute more complex strategy evaluations

include/bpftune/bpftune.h

@@ -144,7 +144,7 @@ struct bpftuner_strategy {
 	const char *name;
 	const char *description;
 	/* return a number to compare with other strategies */
-	int (*evaluate)(struct bpftuner *tuner, struct bpftuner_strategy *strategy);
+	long double (*evaluate)(struct bpftuner *tuner, struct bpftuner_strategy *strategy);
 	unsigned long timeout;	/* time in seconds until evaluation */
 	const char **bpf_progs;	/* programs to load in BPF skeleton for this
 				 * strategy; if NULL, all */

src/libbpftune.c

@@ -1534,7 +1534,7 @@ int bpftune_module_unload(const char *name)
 static void bpftuner_strategy_update(struct bpftuner *tuner)
 {
 	struct bpftuner_strategy *strategy, *max_strategy = NULL;
-	int curr, max = 0;
+	long double curr, max = 0;
 
 	if (!tuner->strategies)
 		return;

test/strategy/strategy_tuner.c

@@ -23,12 +23,12 @@
 #include "strategy_tuner.skel.legacy.h"
 #include "strategy_tuner.skel.nobtf.h"
 
-static int evaluate_A(struct bpftuner *tuner, struct bpftuner_strategy *strategy)
+static long double evaluate_A(struct bpftuner *tuner, struct bpftuner_strategy *strategy)
 {
 	if (tuner->strategy == strategy)
-		return 0;
+		return (long double)0;
 	else
-		return 1;
+		return (long double)1;
 }
 
 const char *progs_A[] = { "entry__proc_dostring_coredump", NULL };
@@ -41,12 +41,12 @@ struct bpftuner_strategy strategy_A = {
 	.bpf_progs	= progs_A,
 };
 
-static int evaluate_B(struct bpftuner *tuner, struct bpftuner_strategy *strategy)
+static long double evaluate_B(struct bpftuner *tuner, struct bpftuner_strategy *strategy)
 {
 	if (tuner->strategy == strategy)
-		return 0;
+		return (long double)0;
 	else
-		return 1;
+		return (long double)1;
 }
 
 const char *progs_B[] = { "entry__proc_dostring", NULL };