commit 3128fda925e745914691382f61bcfb0856a620f4
author Jyoti Bhayana <jbhayana@google.com> Thu Apr 27 18:27:56 2023 -0700
committer Jyoti Bhayana <jbhayana@google.com> Wed May 31 17:22:44 2023 +0000
tree 5b3b1837211585a7e51121d9e9c1f6025addc858
parent 5a1f004db99e84b3b6ab7bbd6909e0c5f032bfa3

Do not use scheduling service in cameraservice.

Since the cameraserver sets the RLIMIT_RTPRIO as 10 in it's
init.rc file, cameraservice can boost the priority of camera
request thread using direct calls till that limit instead of
using scheduling service.

Bug: 231557017
Test: Test using a simple camera2 ndk program which opens the camera and
capture a still image.

Change-Id: Iedba796f9a74e87f9d93f243617ec4895206a3cb

services/camera/libcameraservice/utils/SchedulingPolicyUtils.cpp

diff --git a/services/camera/libcameraservice/utils/SchedulingPolicyUtils.cpp b/services/camera/libcameraservice/utils/SchedulingPolicyUtils.cpp
new file mode 100644
index 0000000..92a1030
--- /dev/null
+++ b/services/camera/libcameraservice/utils/SchedulingPolicyUtils.cpp
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "SchedulingPolicyUtils.h"
+
+#include <errno.h>
+#include <pthread.h>
+#include <sched.h>
+
+#include "CameraThreadState.h"
+#include <private/android_filesystem_config.h>
+#include <processgroup/processgroup.h>
+#include <processgroup/sched_policy.h>
+#include <procinfo/process.h>
+#include <utils/Log.h>
+
+namespace android {
+namespace camera3 {
+namespace SchedulingPolicyUtils {
+
+int requestPriorityDirect(int pid, int tid, int prio) {
+    android::procinfo::ProcessInfo processInfo;
+    static const int kMinPrio = 1;
+    static const int kMaxPrio = 3;
+
+    if (!android::procinfo::GetProcessInfo(tid, &processInfo)) {
+       ALOGE("%s: Error getting process info", __FUNCTION__);
+       return -EPERM;
+    }
+
+    if (prio < kMinPrio || prio > kMaxPrio || processInfo.pid != pid) {
+        ALOGE("%s: Invalid parameter prio=%d pid=%d procinfo.pid=%d", __FUNCTION__, prio, pid,
+                processInfo.pid);
+        return -EPERM;
+    }
+
+    // Set the thread group as audio system thread group in consistent with the
+    // implementation in SchedulingPolicyService.java when isApp is false in
+    // requestPriority method.
+    if (!SetTaskProfiles(tid, {get_sched_policy_profile_name(SP_AUDIO_SYS)},
+            /*use_fd_cache*/ true)) {
+        ALOGE("%s:Error in  SetTaskProfiles", __FUNCTION__);
+        return -EPERM;
+    }
+
+    struct sched_param param;
+    param.sched_priority = prio;
+    return sched_setscheduler(tid, SCHED_FIFO | SCHED_RESET_ON_FORK, &param);
+}
+
+} // namespace SchedulingPolicyUtils
+} // namespace camera3
+} // namespace android