Add memory locking for deterministic PLC execution

core/src/plc_app/plc_state_manager.c

@@ -23,8 +23,9 @@ void *plc_cycle_thread(void *arg)
 {
     PluginManager *pm = (PluginManager *)arg;
 
-    // Initialize PLC
+    // Initialize PLC with real-time optimizations
     set_realtime_priority();
+    lock_memory();
     symbols_init(pm);
     ext_config_init__();
     ext_glueVars();

core/src/plc_app/utils/utils.c

@@ -2,6 +2,7 @@
 #include <errno.h>
 #include <stdlib.h>
 #include <string.h>
+#include <sys/mman.h>
 #include <unistd.h>
 
 unsigned long long *ext_common_ticktime__ = NULL;
@@ -55,6 +56,19 @@ void set_realtime_priority(void)
     }
 }
 
+// Lock all memory pages to prevent page faults during PLC execution
+void lock_memory(void)
+{
+    if (mlockall(MCL_CURRENT | MCL_FUTURE) != 0)
+    {
+        log_error("mlockall failed: %s", strerror(errno));
+    }
+    else
+    {
+        log_info("Memory locked successfully (MCL_CURRENT | MCL_FUTURE)");
+    }
+}
+
 size_t parse_hex_string(const char *hex_string, uint8_t *data)
 {
     size_t count = 0;

core/src/plc_app/utils/utils.h

@@ -3,6 +3,7 @@
 
 #include <dlfcn.h>
 #include <sched.h>
+#include <sys/mman.h>
 #include <time.h>
 #include <stdint.h>
 
@@ -42,6 +43,14 @@ void timespec_diff(struct timespec *a, struct timespec *b,
  */
 void set_realtime_priority(void);
 
+/**
+ * @brief Lock all current and future memory pages to prevent page faults
+ * 
+ * This prevents the kernel from swapping out memory pages during PLC execution,
+ * which could cause unpredictable latency spikes in the scan cycle.
+ */
+void lock_memory(void);
+
 /**
  * @brief Parse a hex string into a byte array
  *