Add a setting for vendor to set uclamp.min boost for SF main thread
Bug: 190137562
Test: boot and check uclamp.min of SF
Change-Id: Iee4bac8e4cfcb33a284bb7c206fe1dc4400e2ded
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index d76c274..c8cb088 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4431,6 +4431,11 @@
}
const auto vsyncPeriod = mRefreshRateConfigs->getCurrentRefreshRate().getVsyncPeriod();
if (currentMode == hal::PowerMode::OFF) {
+ // Keep uclamp in a separate syscall and set it before changing to RT due to b/190237315.
+ // We can merge the syscall later.
+ if (SurfaceFlinger::setSchedAttr(true) != NO_ERROR) {
+ ALOGW("Couldn't set uclamp.min on display on: %s\n", strerror(errno));
+ }
if (SurfaceFlinger::setSchedFifo(true) != NO_ERROR) {
ALOGW("Couldn't set SCHED_FIFO on display on: %s\n", strerror(errno));
}
@@ -4449,6 +4454,9 @@
if (SurfaceFlinger::setSchedFifo(false) != NO_ERROR) {
ALOGW("Couldn't set SCHED_OTHER on display off: %s\n", strerror(errno));
}
+ if (SurfaceFlinger::setSchedAttr(false) != NO_ERROR) {
+ ALOGW("Couldn't set uclamp.min on display off: %s\n", strerror(errno));
+ }
if (display->isPrimary() && currentMode != hal::PowerMode::DOZE_SUSPEND) {
mScheduler->disableHardwareVsync(true);
mScheduler->onScreenReleased(mAppConnectionHandle);
@@ -5797,6 +5805,44 @@
if (sched_setscheduler(0, sched_policy, ¶m) != 0) {
return -errno;
}
+
+ return NO_ERROR;
+}
+
+status_t SurfaceFlinger::setSchedAttr(bool enabled) {
+ static const unsigned int kUclampMin =
+ base::GetUintProperty<unsigned int>("ro.surface_flinger.uclamp.min", 0U);
+
+ if (!kUclampMin) {
+ // uclamp.min set to 0 (default), skip setting
+ return NO_ERROR;
+ }
+
+ // Currently, there is no wrapper in bionic: b/183240349.
+ struct sched_attr {
+ uint32_t size;
+ uint32_t sched_policy;
+ uint64_t sched_flags;
+ int32_t sched_nice;
+ uint32_t sched_priority;
+ uint64_t sched_runtime;
+ uint64_t sched_deadline;
+ uint64_t sched_period;
+ uint32_t sched_util_min;
+ uint32_t sched_util_max;
+ };
+
+ sched_attr attr = {};
+ attr.size = sizeof(attr);
+
+ attr.sched_flags = (SCHED_FLAG_KEEP_ALL | SCHED_FLAG_UTIL_CLAMP);
+ attr.sched_util_min = enabled ? kUclampMin : 0;
+ attr.sched_util_max = 1024;
+
+ if (syscall(__NR_sched_setattr, 0, &attr, 0)) {
+ return -errno;
+ }
+
return NO_ERROR;
}
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 30d76af..09f3ec7 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -191,6 +191,9 @@
// set main thread scheduling policy
static status_t setSchedFifo(bool enabled) ANDROID_API;
+ // set main thread scheduling attributes
+ static status_t setSchedAttr(bool enabled);
+
static char const* getServiceName() ANDROID_API { return "SurfaceFlinger"; }
// This is the phase offset in nanoseconds of the software vsync event
diff --git a/services/surfaceflinger/main_surfaceflinger.cpp b/services/surfaceflinger/main_surfaceflinger.cpp
index 9686523..673239d 100644
--- a/services/surfaceflinger/main_surfaceflinger.cpp
+++ b/services/surfaceflinger/main_surfaceflinger.cpp
@@ -89,6 +89,12 @@
// binder threads to 4.
ProcessState::self()->setThreadPoolMaxThreadCount(4);
+ // Set uclamp.min setting on all threads, maybe an overkill but we want
+ // to cover important threads like RenderEngine.
+ if (SurfaceFlinger::setSchedAttr(true) != NO_ERROR) {
+ ALOGW("Couldn't set uclamp.min: %s\n", strerror(errno));
+ }
+
// The binder threadpool we start will inherit sched policy and priority
// of (this) creating thread. We want the binder thread pool to have
// SCHED_FIFO policy and priority 1 (lowest RT priority)