Cleanup Linux OOM adjustment code.

Review-Url: https://codereview.chromium.org/2744783002
Cr-Commit-Position: refs/heads/master@{#456205}

chrome/app/chrome_main_delegate.cc

@@ -62,12 +62,13 @@
 #if defined(OS_WIN)
 #include <atlbase.h>
 #include <malloc.h>
+
 #include <algorithm>
+
 #include "base/debug/close_handle_hook_win.h"
 #include "chrome/browser/downgrade/user_data_downgrade.h"
 #include "chrome/child/v8_breakpad_support_win.h"
 #include "chrome/common/child_process_logging.h"
-#include "components/crash/content/app/crashpad.h"
 #include "sandbox/win/src/sandbox.h"
 #include "ui/base/resource/resource_bundle_win.h"
 #endif
@@ -78,7 +79,6 @@
 #include "chrome/browser/mac/relauncher.h"
 #include "chrome/browser/shell_integration.h"
 #include "chrome/common/mac/cfbundle_blocker.h"
-#include "components/crash/content/app/crashpad.h"
 #include "components/crash/core/common/objc_zombie.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 #endif
@@ -127,6 +127,7 @@
 
 #if defined(OS_MACOSX) || defined(OS_WIN)
 #include "chrome/browser/policy/policy_path_parser.h"
+#include "components/crash/content/app/crashpad.h"
 #endif
 
 #if defined(OS_CHROMEOS)
@@ -222,7 +223,7 @@ bool UseHooks() {
 #endif  // defined(OS_WIN)
 
 #if defined(OS_LINUX)
-static void AdjustLinuxOOMScore(const std::string& process_type) {
+void AdjustLinuxOOMScore(const std::string& process_type) {
   // Browsers and zygotes should still be killable, but killed last.
   const int kZygoteScore = 0;
   // The minimum amount to bump a score by.  This is large enough that
@@ -271,6 +272,9 @@ static void AdjustLinuxOOMScore(const std::string& process_type) {
   } else {
     NOTREACHED() << "Unknown process type";
   }
+  // In the case of a 0 score, still try to adjust it. Most likely the score is
+  // 0 already, but it may not be if this process inherited a higher score from
+  // its parent process.
   if (score > -1)
     base::AdjustOOMScore(base::GetCurrentProcId(), score);
 }

content/browser/zygote_host/zygote_host_impl_linux.cc

@@ -244,38 +244,40 @@ void ZygoteHostImpl::AdjustRendererOOMScore(base::ProcessHandle pid,
     base::FileEnumerator en(kSelinuxPath, false, base::FileEnumerator::FILES);
     bool has_selinux_files = !en.Next().empty();
 
-    selinux = access(kSelinuxPath.value().c_str(), X_OK) == 0 &&
-              has_selinux_files;
+    selinux =
+        has_selinux_files && access(kSelinuxPath.value().c_str(), X_OK) == 0;
     selinux_valid = true;
   }
 
-  if (use_suid_sandbox_for_adj_oom_score_ && !selinux) {
-    // If heap profiling is running, these processes are not exiting, at least
-    // on ChromeOS. The easiest thing to do is not launch them when profiling.
-    // TODO(stevenjb): Investigate further and fix.
-    if (base::allocator::IsHeapProfilerRunning())
-      return;
-
-    std::vector<std::string> adj_oom_score_cmdline;
-    adj_oom_score_cmdline.push_back(sandbox_binary_);
-    adj_oom_score_cmdline.push_back(sandbox::kAdjustOOMScoreSwitch);
-    adj_oom_score_cmdline.push_back(base::Int64ToString(pid));
-    adj_oom_score_cmdline.push_back(base::IntToString(score));
-
-    base::Process sandbox_helper_process;
-    base::LaunchOptions options;
-
-    // sandbox_helper_process is a setuid binary.
-    options.allow_new_privs = true;
-
-    sandbox_helper_process =
-        base::LaunchProcess(adj_oom_score_cmdline, options);
-    if (sandbox_helper_process.IsValid())
-      base::EnsureProcessGetsReaped(sandbox_helper_process.Pid());
-  } else if (!use_suid_sandbox_for_adj_oom_score_) {
+  if (!use_suid_sandbox_for_adj_oom_score_) {
     if (!base::AdjustOOMScore(pid, score))
       PLOG(ERROR) << "Failed to adjust OOM score of renderer with pid " << pid;
+    return;
   }
+
+  if (selinux)
+    return;
+
+  // If heap profiling is running, these processes are not exiting, at least
+  // on ChromeOS. The easiest thing to do is not launch them when profiling.
+  // TODO(stevenjb): Investigate further and fix.
+  if (base::allocator::IsHeapProfilerRunning())
+    return;
+
+  std::vector<std::string> adj_oom_score_cmdline;
+  adj_oom_score_cmdline.push_back(sandbox_binary_);
+  adj_oom_score_cmdline.push_back(sandbox::kAdjustOOMScoreSwitch);
+  adj_oom_score_cmdline.push_back(base::Int64ToString(pid));
+  adj_oom_score_cmdline.push_back(base::IntToString(score));
+
+  // sandbox_helper_process is a setuid binary.
+  base::LaunchOptions options;
+  options.allow_new_privs = true;
+
+  base::Process sandbox_helper_process =
+      base::LaunchProcess(adj_oom_score_cmdline, options);
+  if (sandbox_helper_process.IsValid())
+    base::EnsureProcessGetsReaped(sandbox_helper_process.Pid());
 }
 #endif