equal probability migrations; specific to Ludwig

1 files changed, 57 insertions, 3 deletions

diff --git a/bin/cache_cost.c b/bin/cache_cost.c
index c41fa01..6e82c62 100644
--- a/bin/cache_cost.c
+++ b/bin/cache_cost.c
@@ -126,13 +126,62 @@ static int touch_mem(int *mem, int wss, int write_cycle)
         return sum;
 }
 
+static int l2buddy(int cpu) {
+        if (cpu % 8 < 4)
+                return cpu + 4;
+        else
+                return cpu - 4;
+}
+
+static int is_l3_buddy(int x, int y) {
+        return x != y && (y % 4) == (x % 4) && x != l2buddy(y);
+}
+
+int kind_counter[] = {0, 0, 0, 0};
+
+static int pick_next_cpu(int num_cpus, int cur_cpu)
+{
+        int next_cpu;
+        int kind;
+
+
+        kind = random() % 4;
+
+        switch (kind) {
+        case 0:
+                /* preemption */
+                next_cpu = cur_cpu;
+                break;
+        case 1:
+                /* L2 */
+                next_cpu = l2buddy(cur_cpu);
+                break;
+        case 2:
+                do {
+                        next_cpu = random() % num_cpus;
+                } while (!is_l3_buddy(next_cpu, cur_cpu));
+                break;
+        case 3:
+                /* mem */
+                do {
+                        next_cpu = random() % num_cpus;
+                } while (next_cpu == cur_cpu || l2buddy(next_cpu) == cur_cpu || is_l3_buddy(next_cpu, cur_cpu));
+                break;
+        }
+        kind_counter[kind]++;
+
+        /* hard coded for ludwig atm */
+
+        return next_cpu;
+}
+
 static void do_random_experiment(FILE* outfile,
                                  int num_cpus, int wss,
                                  int sleep_min, int sleep_max,
                                  int write_cycle, int sample_count)
 {
         int last_cpu, next_cpu, delay;
-        unsigned long counter = 1;
+        unsigned long counter = 1, enough = 0, i;
 
         cycles_t start, stop;
         cycles_t cold, hot1, hot2, hot3, after_resume;
@@ -147,9 +196,9 @@ static void do_random_experiment(FILE* outfile,
 
 
         iopl(3);
-        while (!sample_count || sample_count >= counter) {
+        while (!enough) {
                 delay = sleep_min + random() % (sleep_max - sleep_min + 1);
-                next_cpu = random() % num_cpus;
+                next_cpu = pick_next_cpu(num_cpus, last_cpu);
 
                 mem = allocate(wss);
 
@@ -199,6 +248,11 @@ static void do_random_experiment(FILE* outfile,
                         after_resume);
                 last_cpu = next_cpu;
                 deallocate(mem);
+                enough = sample_count;
+                for (i = 0; i < 4; i++) {
+                        if (kind_counter[i] < sample_count)
+                                enough = 0;
+                }
         }
 }