Add -b (background cache-thrashing loop) option to rtspin

1 files changed, 33 insertions, 9 deletions

diff --git a/bin/rtspin.c b/bin/rtspin.c
index e45f376..151b545 100644
--- a/bin/rtspin.c
+++ b/bin/rtspin.c
@@ -17,22 +17,29 @@
 
 
 static void usage(char *error) {
-        fprintf(stderr, "Error: %s\n", error);
+        if (error)
+                fprintf(stderr, "Error: %s\n", error);
         fprintf(stderr,
                 "Usage:\n"
-                "       rt_spin [COMMON-OPTS] WCET PERIOD DURATION\n"
-                "       rt_spin [COMMON-OPTS] -f FILE [-o COLUMN] WCET PERIOD\n"
-                "       rt_spin -l\n"
+                "       (1) rtspin [COMMON-OPTS] WCET PERIOD DURATION\n"
+                "       (2) rtspin [COMMON-OPTS] -f FILE [-o COLUMN] WCET PERIOD\n"
+                "       (3) rtspin -l\n"
+                "       (4) rtspin -B\n"
+                "\n"
+                "Modes: (1) run as periodic task with given WCET and PERIOD\n"
+                "       (2) as (1), but load per-job execution times from CSV file\n"
+                "       (3) Run calibration loop (how accurately are target runtimes met?)\n"
+                "       (4) Run background, non-real-time cache-thrashing loop (w/ -m).\n"
                 "\n"
                 "COMMON-OPTS = [-w] [-s SCALE]\n"
                 "              [-p PARTITION/CLUSTER [-z CLUSTER SIZE]] [-c CLASS]\n"
                 "              [-X LOCKING-PROTOCOL] [-L CRITICAL SECTION LENGTH] [-Q RESOURCE-ID]\n"
-                "              [-m RESIDENT SET SIZE]"
+                "              [-m RESIDENT SET SIZE]\n"
                 "\n"
                 "WCET and PERIOD are milliseconds, DURATION is seconds.\n"
                 "CRITICAL SECTION LENGTH is in milliseconds.\n"
                 "RESIDENT SET SIZE is in number of pages\n");
-        exit(EXIT_FAILURE);
+        exit(error ? EXIT_FAILURE : EXIT_SUCCESS);
 }
 
 /*
@@ -207,7 +214,7 @@ static int job(double exec_time, double program_end, int lock_od, double cs_leng
         }
 }
 
-#define OPTSTR "p:c:wlveo:f:s:m:q:r:X:L:Q:viRu:B:"
+#define OPTSTR "p:c:wlveo:f:s:m:q:r:X:L:Q:viRu:Bh"
 int main(int argc, char** argv)
 {
         int ret;
@@ -222,6 +229,7 @@ int main(int argc, char** argv)
         int opt;
         int wait = 0;
         int test_loop = 0;
+        int background_loop = 0;
         int column = 1;
         const char *file = NULL;
         int want_enforcement = 0;
@@ -282,6 +290,9 @@ int main(int argc, char** argv)
                 case 'l':
                         test_loop = 1;
                         break;
+                case 'B':
+                        background_loop = 1;
+                        break;
                 case 'o':
                         column = atoi(optarg);
                         break;
@@ -317,6 +328,9 @@ int main(int argc, char** argv)
                 case 'v':
                         verbose = 1;
                         break;
+                case 'h':
+                        usage(NULL);
+                        break;
                 case 'i':
                         report_interrupts = 1;
                         break;
@@ -330,7 +344,7 @@ int main(int argc, char** argv)
                 }
         }
 
-        if(nr_of_pages) {
+        if (nr_of_pages) {
                 page_size = getpagesize();
                 rss = page_size * nr_of_pages;
                 base = mmap(NULL, rss, PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
@@ -350,12 +364,22 @@ int main(int argc, char** argv)
                                 memset(base + (idx * page_size), 1, page_size);
         }
 
+        srand(getpid());
+
         if (test_loop) {
                 debug_delay_loop();
                 return 0;
         }
 
-        srand(getpid());
+        if (background_loop) {
+                while (1) {
+                        if (nr_of_pages)
+                                loop_once_with_mem();
+                        else
+                                loop_once();
+                }
+                return 0;
+        }
 
         if (file) {
                 get_exec_times(file, column, &num_jobs, &exec_times);