Changeset 980611d5 in mainline

Timestamp:

2019-01-01T17:43:54Z (6 years ago)

Author:

Vojtech Horky <vojtech.horky@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

7e85d2b

Parents:

d5caf79

Message:

perf: use uint64_t for workload size

We also check that we do not overflow with uint64_t (that can rarely
happen if the benchmark is properly designed but we want to be on the
safe side).

File:

• uspace/app/perf/perf.c (modified) (2 diffs)

uspace/app/perf/perf.c

@@ -107 +107 @@
         }
 
-        size_t workload_size = 1;
-
-        while (true) {
+        /*
+         * Find workload size that is big enough to last few seconds.
+         * We also check that uint64_t is big enough.
+         */
+        uint64_t workload_size = 0;
+        for (size_t bits = 0; bits <= 64; bits++) {
+                if (bits == 64) {
+                        str_cpy(error_msg, MAX_ERROR_STR_LENGTH, "Workload too small even for 1 << 63");
+                        goto leave_error;
+                }
+                workload_size = ((uint64_t) 1) << bits;
+
                 stopwatch_t stopwatch = STOPWATCH_INITIALIZE_STATIC;
 
@@ -123 +132 @@
                         break;
                 }
-                workload_size *= 2;
-        }
-
-        printf("Workload size set to %zu, measuring %d samples.\n", workload_size, NUM_SAMPLES);
+        }
+
+        printf("Workload size set to %" PRIu64 ", measuring %d samples.\n", workload_size, NUM_SAMPLES);
 
         stopwatch_t *stopwatch = calloc(NUM_SAMPLES, sizeof(stopwatch_t));