Linux: Adjust /proc/pid/oom_adj to sacrifice plugin and renderer processes to...

base/process_util_linux.cc

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/process_util.h"
 
 #include <ctype.h>
 #include <dirent.h>
 #include <dlfcn.h>
 #include <errno.h>
@@ skipping 495 matching lines @@
   CHECK(false) << "Out of memory.";
 }
 
 void OnNoMemory() {
   OnNoMemorySize(0);
 }
 
 }  // namespace
 
 extern "C" {
-
 #if !defined(LINUX_USE_TCMALLOC)
 
 typedef void* (*malloc_type)(size_t size);
 typedef void* (*valloc_type)(size_t size);
 typedef void* (*pvalloc_type)(size_t size);
 
 typedef void* (*calloc_type)(size_t nmemb, size_t size);
 typedef void* (*realloc_type)(void *ptr, size_t size);
 typedef void* (*memalign_type)(size_t boundary, size_t size);
 
@@ skipping 66 matching lines @@
 int posix_memalign(void** ptr, size_t alignment, size_t size) {
   static posix_memalign_type original_function =
       reinterpret_cast<posix_memalign_type>(dlsym(RTLD_NEXT, "posix_memalign"));
   int ret = original_function(ptr, alignment, size);
   if (ret == ENOMEM)
     OnNoMemorySize(size);
   return ret;
 }
 
 #endif  // !defined(LINUX_USE_TCMALLOC)
-
 }  // extern C
 
 void EnableTerminationOnOutOfMemory() {
   // Set the new-out of memory handler.
   std::set_new_handler(&OnNoMemory);
   // If we're using glibc's allocator, the above functions will override
   // malloc and friends and make them die on out of memory.
 }
 
+bool AdjustOOMScore(ProcessId process, int score) {
+  if (score < 0 || score > 15)
+    return false;
+
+  FilePath oom_adj("/proc");
+  oom_adj = oom_adj.Append(Int64ToString(process));
+  oom_adj = oom_adj.AppendASCII("oom_adj");
+
+  if (!file_util::PathExists(oom_adj))
+    return false;
+
+  std::string score_str = IntToString(score);
+  return (static_cast<int>(score_str.length()) ==
+          file_util::WriteFile(oom_adj, score_str.c_str(), score_str.length()));
+}
+
 }  // namespace base