Merge pull request #1188 from filipe-norte-red/wpe-2.38-pressure-settings

Tune memory pressure settings for rapid mem usage changes

Author: magomez

Source/WTF/wtf/unix/MemoryPressureHandlerUnix.cpp

@@ -53,8 +53,13 @@ namespace WTF {
 // we wait longer to try again (s_maximumHoldOffTime).
 // These value seems reasonable and testing verifies that it throttles frequent
 // low memory events, greatly reducing CPU usage.
+#if PLATFORM(WPE)
+static const Seconds s_minimumHoldOffTime { 1_s };
+static const Seconds s_maximumHoldOffTime { 1_s };
+#else
 static const Seconds s_minimumHoldOffTime { 5_s };
 static const Seconds s_maximumHoldOffTime { 30_s };
+#endif
 static const size_t s_minimumBytesFreedToUseMinimumHoldOffTime = 1 * MB;
 static const unsigned s_holdOffMultiplier = 20;
 
@@ -69,7 +74,9 @@ void MemoryPressureHandler::triggerMemoryPressureEvent(bool isCritical)
     setMemoryPressureStatus(MemoryPressureStatus::SystemCritical);
 
     ensureOnMainThread([this, isCritical] {
-        respondToMemoryPressure(isCritical ? Critical::Yes : Critical::No);
+        // When memory usage reaches the critical state, we may not release enough memory in time if we use the
+        // async mode, so use synchrounous mode in such case
+        respondToMemoryPressure(isCritical ? Critical::Yes : Critical::No, isCritical ? Synchronous::Yes : Synchronous::No);
     });
 
     if (ReliefLogger::loggingEnabled() && isUnderMemoryPressure())

Source/WebKit/UIProcess/linux/MemoryPressureMonitor.cpp

@@ -48,8 +48,13 @@ static const Seconds s_minPollingInterval { 1_s };
 static const Seconds s_maxPollingInterval { 5_s };
 static const double s_minUsedMemoryPercentageForPolling = 50;
 static const double s_maxUsedMemoryPercentageForPolling = 85;
+#if PLATFORM(WPE)
+static const int s_memoryPresurePercentageThreshold = 80;
+static const int s_memoryPresurePercentageThresholdCritical = 85;
+#else
 static const int s_memoryPresurePercentageThreshold = 90;
 static const int s_memoryPresurePercentageThresholdCritical = 95;
+#endif
 // cgroups.7: The usual place for such mounts is under a tmpfs(5)
 // filesystem mounted at /sys/fs/cgroup.
 static const char* s_cgroupMemoryPath = "/sys/fs/cgroup/%s/%s/%s";