[RHEL8][CONTAINER] Runtime check when creating pThreads

It looks like :
  - when running on a Fedora-host
  - with generic kernel
  - in a container
  - even in privileged mode

That is not enough and priority/schedule settings is not allowed.

So at runtime, we check and in case, we don't set up priorities.
Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

common/utils/system.c

@@ -96,6 +96,51 @@ static void read_pipe(int p, char *b, int size) {
   }
 }
 
+static int baseRunTimeCommand(char* cmd) {
+  FILE *fp;
+  size_t retSize = 0;
+
+  fp = popen(cmd, "r");
+
+  memset(cmd, 1, 200);
+  retSize = fread(cmd, 1, 200, fp);
+  fclose(fp);
+
+  if (retSize == 0) {
+    return 0;
+  }
+  return atoi(cmd);
+}
+
+int checkIfFedoraDistribution(void) {
+  char cmd[200];
+
+  memset(cmd, 1, 200);
+  sprintf(cmd, "cat /etc/os-release | grep ID_LIKE | grep -ic fedora || true");
+  return baseRunTimeCommand(cmd);
+}
+
+int checkIfGenericKernelOnFedora(void) {
+  char cmd[200];
+
+  memset(cmd, 1, 200);
+  sprintf(cmd, "uname -a | grep -c rt || true");
+  return (1 - baseRunTimeCommand(cmd));
+}
+
+int checkIfInsideContainer(void) {
+  char cmd[200];
+  int res = 0;
+
+  memset(cmd, 1, 200);
+  sprintf(cmd, "cat /proc/self/cgroup | egrep -c 'libpod|podman|kubepods' || true");
+  res = baseRunTimeCommand(cmd);
+  if (res > 0)
+    return 1;
+  else
+    return 0;
+}
+
 /********************************************************************/
 /* background process                                               */
 /********************************************************************/
@@ -200,12 +245,19 @@ void start_background_system(void) {
 void threadCreate(pthread_t* t, void * (*func)(void*), void * param, char* name, int affinity, int priority){
   pthread_attr_t attr;
   int ret;
+  int settingPriority = 1;
   ret=pthread_attr_init(&attr);
   AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
   ret=pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_DETACHED);
   AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
   ret=pthread_attr_setinheritsched(&attr, PTHREAD_EXPLICIT_SCHED);
   AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
+  if (checkIfFedoraDistribution())
+    if (checkIfGenericKernelOnFedora())
+      if (checkIfInsideContainer())
+        settingPriority = 0;
+
+  if (settingPriority) {
     ret=pthread_attr_setschedpolicy(&attr, SCHED_OAI);
     AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
     if(priority<sched_get_priority_min(SCHED_OAI) || priority>sched_get_priority_max(SCHED_FIFO)) {
@@ -223,6 +275,8 @@ void threadCreate(pthread_t* t, void * (*func)(void*), void * param, char* name,
     sparam.sched_priority = priority;
     ret=pthread_attr_setschedparam(&attr, &sparam);
     AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
+  }
+
   ret=pthread_create(t, &attr, func, param);
   AssertFatal(ret==0,"ret: %d, errno: %d\n",ret, errno);
 

common/utils/system.h

@@ -58,6 +58,14 @@ void thread_top_init(char *thread_name,
                      uint64_t deadline,
                      uint64_t period);
 
+/****************************************************
+ * Functions to check system at runtime.
+ ****************************************************/
+
+int checkIfFedoraDistribution(void);
+int checkIfGenericKernelOnFedora(void);
+int checkIfInsideContainer(void);
+
 #ifdef __cplusplus
 }
 #endif

targets/RT/USER/lte-ue.c

@@ -32,6 +32,7 @@
 #include "lte-softmodem.h"
 
 #include "rt_wrapper.h"
+#include "system.h"
 
 #include "LAYER2/MAC/mac.h"
 #include "RRC/LTE/rrc_extern.h"
@@ -230,7 +231,14 @@ void init_thread(int sched_runtime,
   }
 
 #else
+  int settingPriority = 1;
 
+  if (checkIfFedoraDistribution())
+    if (checkIfGenericKernelOnFedora())
+      if (checkIfInsideContainer())
+        settingPriority = 0;
+
+  if (settingPriority) {
     if (CPU_COUNT(cpuset) > 0)
       AssertFatal( 0 == pthread_setaffinity_np(pthread_self(), sizeof(cpu_set_t), cpuset), "");
 
@@ -238,6 +246,8 @@ void init_thread(int sched_runtime,
     sp.sched_priority = sched_fifo;
     AssertFatal(pthread_setschedparam(pthread_self(),SCHED_FIFO,&sp)==0,
                 "Can't set thread priority, Are you root?\n");
+  }
+
   /* Check the actual affinity mask assigned to the thread */
   cpu_set_t *cset=CPU_ALLOC(CPU_SETSIZE);
 

targets/RT/USER/rt_wrapper.c

@@ -43,6 +43,7 @@
 #include <getopt.h>
 #include <sys/sysinfo.h>
 #include "rt_wrapper.h"
+#include "system.h"
 #include <errno.h>
 #include <common/utils/msc/msc.h>
 
@@ -294,6 +295,7 @@ void thread_top_init(char *thread_name,
   struct sched_param sparam;
   char cpu_affinity[1024];
   cpu_set_t cpuset;
+  int settingPriority = 1;
 
   /* Set affinity mask to include CPUs 2 to MAX_CPUS */
   /* CPU 0 is reserved for UHD threads */
@@ -340,9 +342,15 @@ void thread_top_init(char *thread_name,
     }
   }
 
+  if (checkIfFedoraDistribution())
+    if (checkIfGenericKernelOnFedora())
+      if (checkIfInsideContainer())
+        settingPriority = 0;
+
+  if (settingPriority) {
     memset(&sparam, 0, sizeof(sparam));
     sparam.sched_priority = sched_get_priority_max(SCHED_FIFO);
-  policy = SCHED_FIFO ; 
+    policy = SCHED_FIFO;
   
     s = pthread_setschedparam(pthread_self(), policy, &sparam);
     if (s != 0) {
@@ -364,6 +372,7 @@ void thread_top_init(char *thread_name,
                      (policy == SCHED_OTHER) ? "SCHED_OTHER" :
                      "???",
                      sparam.sched_priority, cpu_affinity );
+  }
 
 #endif //LOW_LATENCY