CameraService: Use SCHED_FIFO for request queue thread in HFR

- Move SchedulingPolicyService from audioservice to mediautils

- When starting up a high speed stream config, set request queue thread
  to SCHED_FIFO using SchedulingPolicyService

Bug: 24227252
Change-Id: I224b59142bd111caf563779f55cddd62385b9bac

3 files changed, 19 insertions, 1 deletions

diff --git a/services/camera/libcameraservice/Android.mk b/services/camera/libcameraservice/Android.mk
index e8ef24e..45900c4 100644
--- a/services/camera/libcameraservice/Android.mk
+++ b/services/camera/libcameraservice/Android.mk
@@ -53,7 +53,7 @@ LOCAL_SRC_FILES:=               \
     device3/StatusTracker.cpp \
     gui/RingBufferConsumer.cpp \
     utils/CameraTraces.cpp \
-    utils/AutoConditionLock.cpp \
+    utils/AutoConditionLock.cpp
 
 LOCAL_SHARED_LIBRARIES:= \
     libui \
diff --git a/services/camera/libcameraservice/device3/Camera3Device.cpp b/services/camera/libcameraservice/device3/Camera3Device.cpp
index 433a745..1a3a770 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.cpp
+++ b/services/camera/libcameraservice/device3/Camera3Device.cpp
@@ -44,6 +44,7 @@
 #include <utils/Timers.h>
 
 #include "utils/CameraTraces.h"
+#include "mediautils/SchedulingPolicyService.h"
 #include "device3/Camera3Device.h"
 #include "device3/Camera3OutputStream.h"
 #include "device3/Camera3InputStream.h"
@@ -1766,6 +1767,21 @@ status_t Camera3Device::configureStreamsLocked() {
     // across configure_streams() calls
     mRequestThread->configurationComplete();
 
+    // Boost priority of request thread for high speed recording to SCHED_FIFO
+    if (mIsConstrainedHighSpeedConfiguration) {
+        pid_t requestThreadTid = mRequestThread->getTid();
+        res = requestPriority(getpid(), requestThreadTid,
+                kConstrainedHighSpeedThreadPriority, true);
+        if (res != OK) {
+            ALOGW("Can't set realtime priority for request processing thread: %s (%d)",
+                    strerror(-res), res);
+        } else {
+            ALOGD("Set real time priority for request queue thread (tid %d)", requestThreadTid);
+        }
+    } else {
+        // TODO: Set/restore normal priority for normal use cases
+    }
+
     // Update device state
 
     mNeedConfig = false;
diff --git a/services/camera/libcameraservice/device3/Camera3Device.h b/services/camera/libcameraservice/device3/Camera3Device.h
index 9d3c533..402cb1d 100644
--- a/services/camera/libcameraservice/device3/Camera3Device.h
+++ b/services/camera/libcameraservice/device3/Camera3Device.h
@@ -161,6 +161,8 @@ class Camera3Device :
     static const nsecs_t       kActiveTimeout     = 500000000;  // 500 ms
     static const size_t        kInFlightWarnLimit = 20;
     static const size_t        kInFlightWarnLimitHighSpeed = 256; // batch size 32 * pipe depth 8
+    // SCHED_FIFO priority for request submission thread in HFR mode
+    static const int           kConstrainedHighSpeedThreadPriority = 3;
 
     struct                     RequestTrigger;
     // minimal jpeg buffer size: 256KB + blob header