Bug 802423 - Updater needs to set oom_adj and nice appropriately. e=ehsan a=b2g-only

toolkit/mozapps/update/updater/updater.cpp

@@ -84,6 +84,14 @@ void LaunchMacPostProcess(const char* aAppExe);
 # include "automounter_gonk.h"
 # include <unistd.h>
 # include <android/log.h>
+# include <linux/ioprio.h>
+# include <sys/resource.h>
+
+// The only header file in bionic which has a function prototype for ioprio_set
+// is libc/include/sys/linux-unistd.h. However, linux-unistd.h conflicts
+// badly with unistd.h, so we declare the prototype for ioprio_set directly.
+extern "C" int ioprio_set(int which, int who, int ioprio);
+
 # define MAYBE_USE_HARD_LINKS 1
 static bool sUseHardLinks = true;
 #else
@@ -2401,6 +2409,35 @@ int NS_main(int argc, NS_tchar **argv)
     LOG(("Performing a replace request"));
   }
 
+#ifdef MOZ_WIDGET_GONK
+  const char *prioEnv = getenv("MOZ_UPDATER_PRIO");
+  if (prioEnv) {
+    int32_t prioVal;
+    int32_t oomScoreAdj;
+    int32_t ioprioClass;
+    int32_t ioprioLevel;
+    if (sscanf(prioEnv, "%d/%d/%d/%d",
+               &prioVal, &oomScoreAdj, &ioprioClass, &ioprioLevel) == 4) {
+      LOG(("MOZ_UPDATER_PRIO=%s", prioEnv));
+      if (setpriority(PRIO_PROCESS, 0, prioVal)) {
+        LOG(("setpriority(%d) failed, errno = %d", prioVal, errno));
+      }
+      if (ioprio_set(IOPRIO_WHO_PROCESS, 0,
+                     IOPRIO_PRIO_VALUE(ioprioClass, ioprioLevel))) {
+        LOG(("ioprio_set(%d,%d) failed: errno = %d",
+             ioprioClass, ioprioLevel, errno));
+      }
+      FILE *fs = fopen("/proc/self/oom_score_adj", "w");
+      if (fs) {
+        fprintf(fs, "%d", oomScoreAdj);
+        fclose(fs);
+      } else {
+        LOG(("Unable to open /proc/self/oom_score_adj for writing, errno = %d", errno));
+      }
+    }
+  }
+#endif
+
 #ifdef XP_WIN
   int possibleWriteError; // Variable holding one of the errors 46-48
   if (pid > 0) {

toolkit/xre/nsUpdateDriver.cpp

@@ -24,6 +24,8 @@
 #include "nsThreadUtils.h"
 #include "nsIXULAppInfo.h"
 #include "mozilla/Preferences.h"
+#include "nsPrintfCString.h"
+#include "mozilla/DebugOnly.h"
 
 #ifdef XP_MACOSX
 #include "nsILocalFileMac.h"
@@ -46,6 +48,8 @@
 # include <unistd.h>
 #endif
 
+using namespace mozilla;
+
 //
 // We use execv to spawn the updater process on all UNIX systems except Mac OSX
 // since it is known to cause problems on the Mac.  Windows has execv, but it
@@ -96,8 +100,20 @@ static const char kUpdaterPNG[] = "updater.png";
 #endif
 
 #if defined(MOZ_WIDGET_GONK)
+#include <linux/ioprio.h>
+
 static const int kB2GServiceArgc = 2;
 static const char *kB2GServiceArgv[] = { "/system/bin/start", "b2g" };
+
+static const char kAppUpdaterPrio[]        = "app.update.updater.prio";
+static const char kAppUpdaterOomScoreAdj[] = "app.update.updater.oom_score_adj";
+static const char kAppUpdaterIOPrioClass[] = "app.update.updater.ioprio.class";
+static const char kAppUpdaterIOPrioLevel[] = "app.update.updater.ioprio.level";
+
+static const int  kAppUpdaterPrioDefault        = 19;     // -20..19 where 19 = lowest priority
+static const int  kAppUpdaterOomScoreAdjDefault = -1000;  // -1000 = Never kill
+static const int  kAppUpdaterIOPrioClassDefault = IOPRIO_CLASS_IDLE;
+static const int  kAppUpdaterIOPrioLevelDefault = 0;      // Doesn't matter for CLASS IDLE
 #endif
 
 static nsresult
@@ -579,8 +595,8 @@ GetOSApplyToDir(nsACString& applyToDir)
   NS_ASSERTION(ds, "Can't get directory service");
 
   nsCOMPtr<nsIFile> osApplyToDir;
-  nsresult rv = ds->Get(XRE_OS_UPDATE_APPLY_TO_DIR, NS_GET_IID(nsIFile),
-                        getter_AddRefs(osApplyToDir));
+  DebugOnly<nsresult> rv = ds->Get(XRE_OS_UPDATE_APPLY_TO_DIR, NS_GET_IID(nsIFile),
+                                   getter_AddRefs(osApplyToDir));
   NS_ASSERTION(NS_SUCCEEDED(rv), "Can't get the OS applyTo dir");
 
   return osApplyToDir->GetNativePath(applyToDir);
@@ -818,6 +834,23 @@ ApplyUpdate(nsIFile *greDir, nsIFile *updateDir, nsIFile *statusFile,
   if (isOSUpdate) {
     PR_SetEnv("MOZ_OS_UPDATE=1");
   }
+#if defined(MOZ_WIDGET_GONK)
+  // We want the updater to be CPU friendly and not subject to being killed by
+  // the low memory killer, so we pass in some preferences to allow it to
+  // adjust its priority.
+
+  int32_t prioVal = Preferences::GetInt(kAppUpdaterPrio,
+                                        kAppUpdaterPrioDefault);
+  int32_t oomScoreAdj = Preferences::GetInt(kAppUpdaterOomScoreAdj,
+                                            kAppUpdaterOomScoreAdjDefault);
+  int32_t ioprioClass = Preferences::GetInt(kAppUpdaterIOPrioClass,
+                                            kAppUpdaterIOPrioClassDefault);
+  int32_t ioprioLevel = Preferences::GetInt(kAppUpdaterIOPrioLevel,
+                                            kAppUpdaterIOPrioLevelDefault);
+  nsPrintfCString prioEnv("MOZ_UPDATER_PRIO=%d/%d/%d/%d",
+                          prioVal, oomScoreAdj, ioprioClass, ioprioLevel);
+  PR_SetEnv(prioEnv.get());
+#endif
 
   LOG(("spawning updater process [%s]\n", updaterPath.get()));