Changeset d70fc74 in mainline

Timestamp:

2012-07-06T12:58:58Z (12 years ago)

Author:

Adam Hraska <adam.hraska+hos@…>

Branches:

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

Children:

ef1603b

Parents:

1f8c11f

Message:

smp_call: Minor fixes and comments.

Location:

kernel

Files:

• generic/src/smp/smp_call.c (modified) (5 diffs)
• test/smpcall/smpcall1.c (modified) (9 diffs)

kernel/generic/src/smp/smp_call.c

@@ -54 +54 @@
  * 
  * If @a cpu_id is the local CPU, the function will be invoked
- * directly.
+ * directly. If the destination cpu id @a cpu_id is invalid
+ * or denotes an inactive cpu, the call is discarded immediately.
  * 
  * Interrupts must be enabled. Otherwise you run the risk
  * of a deadlock.
  * 
- * @param cpu_id Destination CPU's logical id (eg CPU->id)
+ * @param cpu_id Destination CPU's logical id (eg CPU->id).
  * @param func Function to call.
  * @param arg Argument to pass to the user supplied function @a func.
@@ -73 +74 @@
         
         /* Discard invalid calls. */
-        if (config.cpu_count <= cpu_id) {
+        if (config.cpu_count <= cpu_id || !cpus[cpu_id].active) {
                 call_start(call_info, func, arg);
                 call_done(call_info);
@@ -81 +82 @@
         /* Protect cpu->id against migration. */
         preemption_disable();
-        
+
         call_start(call_info, func, arg);
         
@@ -89 +90 @@
                 list_append(&call_info->calls_link, &cpus[cpu_id].smp_pending_calls);
                 spinlock_unlock(&cpus[cpu_id].smp_calls_lock);
-                                
+
+                /*
+                 * If a platform supports SMP it must implement arch_smp_call_ipi().
+                 * It should issue an IPI an cpu_id and invoke smp_call_ipi_recv()
+                 * on cpu_id in turn. 
+                 * 
+                 * Do not implement as just an empty dummy function. Instead
+                 * consider providing a full implementation or at least a version 
+                 * that panics if invoked. Note that smp_call_async() never
+                 * calls arch_smp_call_ipi() on uniprocessors even if CONFIG_SMP.
+                 */
                 arch_smp_call_ipi(cpu_id);
 #endif
@@ -131 +142 @@
 /** Architecture independent smp call IPI handler.
  * 
- * Interrupts must be disabled.
+ * Interrupts must be disabled. Tolerates spurious calls.
  */
 void smp_call_ipi_recv(void)

kernel/test/smpcall/smpcall1.c

@@ -14 +14 @@
 /* 
  * Maximum total number of smp_calls in the system is: 
- *  128000 == 8^2 * 1000 * 2 
+ *  162000 == 9^2 * 1000 * 2 
  *  == MAX_CPUS^2 * ITERATIONS * EACH_CPU_INC_PER_ITER
  */
-#define MAX_CPUS   8
+#define MAX_CPUS   9
 #define ITERATIONS 1000
 #define EACH_CPU_INC_PER_ITER 2
@@ -40 +40 @@
         smp_call_t call_info[MAX_CPUS];
         
-        size_t cpu_count = min(config.cpu_count, MAX_CPUS);
+        unsigned int cpu_count = min(config.cpu_active, MAX_CPUS);
         
         for (int iter = 0; iter < ITERATIONS; ++iter) {
@@ -75 +75 @@
 }
 
+static size_t calc_exp_calls(size_t thread_cnt)
+{
+        return thread_cnt * ITERATIONS * EACH_CPU_INC_PER_ITER;
+}
 
 const char *test_smpcall1(void)
@@ -82 +86 @@
         thread_t *thread[MAX_CPUS] = {0};
         
-        unsigned int cpu_count = min(config.cpu_count, MAX_CPUS);
+        unsigned int cpu_count = min(config.cpu_active, MAX_CPUS);
         size_t running_thread_cnt = 0;
 
@@ -100 +104 @@
         }
 
-        TPRINTF("Running %u wired threads.\n", running_thread_cnt);
+        size_t exp_calls = calc_exp_calls(running_thread_cnt);
+        size_t exp_calls_sum = exp_calls * cpu_count;
+        
+        TPRINTF("Running %zu wired threads. Expecting %zu calls. Be patient.\n", 
+                running_thread_cnt, exp_calls_sum);
 
         for (unsigned int i = 0; i < cpu_count; ++i) {
@@ -112 +120 @@
                 if (thread[i] != NULL) {
                         thread_join(thread[i]);
+                        thread_detach(thread[i]);
                 }
         }
 
         TPRINTF("Threads finished. Checking number of smp_call()s.\n");
-        
-        size_t exp_calls = running_thread_cnt * ITERATIONS * EACH_CPU_INC_PER_ITER;
-        size_t exp_calls_sum = exp_calls * cpu_count;
         
         bool ok = true;
@@ -127 +133 @@
                         if (call_cnt[i] != exp_calls) {
                                 ok = false;
-                                TPRINTF("Error: %u instead of %u cpu%u's calls were"
+                                TPRINTF("Error: %zu instead of %zu cpu%u's calls were"
                                         " acknowledged.\n", call_cnt[i], exp_calls, i);
                         } 
@@ -136 +142 @@
         
         if (calls_sum != exp_calls_sum) {
-                TPRINTF("Error: total acknowledged sum: %u instead of %u.\n",
+                TPRINTF("Error: total acknowledged sum: %zu instead of %zu.\n",
                         calls_sum, exp_calls_sum);
                 
@@ -143 +149 @@
         
         if (ok) {
-                TPRINTF("Success: number of received smp_calls is as expected (%u).\n",
+                TPRINTF("Success: number of received smp_calls is as expected (%zu).\n",
                         exp_calls_sum);
                 return NULL;