tici: fix set_realtime_priority (#2124)

* cleanup and pin modeld to core 5

* Unused import
old-commit-hash: 5c058140ed

common/realtime.py

@@ -1,12 +1,11 @@
 """Utilities for reading real time clocks and keeping soft real time constraints."""
-import os
 import time
 import platform
 import subprocess
 import multiprocessing
 from cffi import FFI
 
-from common.hardware import ANDROID
+from common.hardware import PC
 from common.common_pyx import sec_since_boot  # pylint: disable=no-name-in-module, import-error
 
 
@@ -21,6 +20,7 @@ ffi = FFI()
 ffi.cdef("long syscall(long number, ...);")
 libc = ffi.dlopen(None)
 
+
 def _get_tid():
   if platform.machine() == "x86_64":
     NR_gettid = 186
@@ -33,21 +33,17 @@ def _get_tid():
 
 
 def set_realtime_priority(level):
-  if os.getuid() != 0:
-    print("not setting priority, not root")
-    return
+  if PC:
+    return -1
+  else:
+    return subprocess.call(['chrt', '-f', '-p', str(level), str(_get_tid())])
 
-  return subprocess.call(['chrt', '-f', '-p', str(level), str(_get_tid())])
 
 def set_core_affinity(core):
-  if os.getuid() != 0:
-    print("not setting affinity, not root")
-    return
-
-  if ANDROID:
-    return subprocess.call(['taskset', '-p', str(core), str(_get_tid())])
-  else:
+  if PC:
     return -1
+  else:
+    return subprocess.call(['taskset', '-p', str(core), str(_get_tid())])
 
 
 class Ratekeeper():

selfdrive/common/util.c

@@ -50,7 +50,6 @@ void set_thread_name(const char* name) {
 
 int set_realtime_priority(int level) {
 #ifdef __linux__
-
   long tid = syscall(SYS_gettid);
 
   // should match python using chrt
@@ -64,8 +63,7 @@ int set_realtime_priority(int level) {
 }
 
 int set_core_affinity(int core) {
-#ifdef QCOM
-
+#ifdef __linux__
   long tid = syscall(SYS_gettid);
   cpu_set_t rt_cpu;
 

selfdrive/modeld/modeld.cc

@@ -92,6 +92,11 @@ int main(int argc, char **argv) {
   int err;
   set_realtime_priority(51);
 
+#ifdef QCOM2
+  // CPU usage is much lower when pinned to a single big core
+  set_core_affinity(4);
+#endif
+
   signal(SIGINT, (sighandler_t)set_do_exit);
   signal(SIGTERM, (sighandler_t)set_do_exit);