--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -603,25 +603,25 @@ pref("hal.processPriorityManager.gonk.MA
 pref("hal.processPriorityManager.gonk.FOREGROUND_HIGH.OomScoreAdjust", 67);
 pref("hal.processPriorityManager.gonk.FOREGROUND_HIGH.KillUnderMB", 5);
 pref("hal.processPriorityManager.gonk.FOREGROUND_HIGH.Nice", 0);
 
 pref("hal.processPriorityManager.gonk.FOREGROUND.OomScoreAdjust", 134);
 pref("hal.processPriorityManager.gonk.FOREGROUND.KillUnderMB", 6);
 pref("hal.processPriorityManager.gonk.FOREGROUND.Nice", 1);
 
-pref("hal.processPriorityManager.gonk.BACKGROUND_PERCEIVABLE.OomScoreAdjust", 200);
+pref("hal.processPriorityManager.gonk.BACKGROUND_PERCEIVABLE.OomScoreAdjust", 400);
 pref("hal.processPriorityManager.gonk.BACKGROUND_PERCEIVABLE.KillUnderMB", 7);
 pref("hal.processPriorityManager.gonk.BACKGROUND_PERCEIVABLE.Nice", 7);
 
-pref("hal.processPriorityManager.gonk.BACKGROUND_HOMESCREEN.OomScoreAdjust", 267);
+pref("hal.processPriorityManager.gonk.BACKGROUND_HOMESCREEN.OomScoreAdjust", 534);
 pref("hal.processPriorityManager.gonk.BACKGROUND_HOMESCREEN.KillUnderMB", 8);
 pref("hal.processPriorityManager.gonk.BACKGROUND_HOMESCREEN.Nice", 18);
 
-pref("hal.processPriorityManager.gonk.BACKGROUND.OomScoreAdjust", 400);
+pref("hal.processPriorityManager.gonk.BACKGROUND.OomScoreAdjust", 667);
 pref("hal.processPriorityManager.gonk.BACKGROUND.KillUnderMB", 20);
 pref("hal.processPriorityManager.gonk.BACKGROUND.Nice", 18);
 
 // Processes get this niceness when they have low CPU priority.
 pref("hal.processPriorityManager.gonk.LowCPUNice", 18);
 
 // Fire a memory pressure event when the system has less than Xmb of memory
 // remaining.  You should probably set this just above Y.KillUnderMB for

--- a/hal/gonk/GonkHal.cpp
+++ b/hal/gonk/GonkHal.cpp
@@ -1056,16 +1056,17 @@ EnsureKernelLowMemKillerParamsSet()
   // GonkMemoryPressureMonitoring.cpp.)
 
   // Build the adj and minfree strings.
   nsAutoCString adjParams;
   nsAutoCString minfreeParams;
 
   int32_t lowerBoundOfNextOomScoreAdj = OOM_SCORE_ADJ_MIN - 1;
   int32_t lowerBoundOfNextKillUnderMB = 0;
+  int32_t countOfLowmemorykillerParametersSets = 0;
 
   for (int i = NUM_PROCESS_PRIORITY - 1; i >= 0; i--) {
     // The system doesn't function correctly if we're missing these prefs, so
     // crash loudly.
 
     ProcessPriority priority = static_cast<ProcessPriority>(i);
 
     int32_t oomScoreAdj;
@@ -1076,32 +1077,36 @@ EnsureKernelLowMemKillerParamsSet()
       MOZ_CRASH();
     }
 
     int32_t killUnderMB;
     if (!NS_SUCCEEDED(Preferences::GetInt(
           nsPrintfCString("hal.processPriorityManager.gonk.%s.KillUnderMB",
                           ProcessPriorityToString(priority)).get(),
           &killUnderMB))) {
-      MOZ_CRASH();
+      continue;
     }
 
     // The LMK in kernel silently malfunctions if we assign the parameters
     // in non-increasing order, so we add this assertion here. See bug 887192.
     MOZ_ASSERT(oomScoreAdj > lowerBoundOfNextOomScoreAdj);
     MOZ_ASSERT(killUnderMB > lowerBoundOfNextKillUnderMB);
 
+    // The LMK in kernel only accept 6 sets of LMK parameters. See bug 914728.
+    MOZ_ASSERT(countOfLowmemorykillerParametersSets < 6);
+
     // adj is in oom_adj units.
     adjParams.AppendPrintf("%d,", OomAdjOfOomScoreAdj(oomScoreAdj));
 
     // minfree is in pages.
     minfreeParams.AppendPrintf("%d,", killUnderMB * 1024 * 1024 / PAGE_SIZE);
 
     lowerBoundOfNextOomScoreAdj = oomScoreAdj;
     lowerBoundOfNextKillUnderMB = killUnderMB;
+    countOfLowmemorykillerParametersSets++;
   }
 
   // Strip off trailing commas.
   adjParams.Cut(adjParams.Length() - 1, 1);
   minfreeParams.Cut(minfreeParams.Length() - 1, 1);
   if (!adjParams.IsEmpty() && !minfreeParams.IsEmpty()) {
     WriteToFile("/sys/module/lowmemorykiller/parameters/adj", adjParams.get());
     WriteToFile("/sys/module/lowmemorykiller/parameters/minfree", minfreeParams.get());