cros: Log per-process memory use on low memory events

chrome/browser/oom_priority_manager.cc

 // Copyright (c) 2012 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 "chrome/browser/oom_priority_manager.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/metrics/histogram.h"
 #include "base/process.h"
 #include "base/process_util.h"
 #include "base/string16.h"
 #include "base/string_number_conversions.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread.h"
 #include "base/timer.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/low_memory_observer.h"
+#include "chrome/browser/memory_details.h"
 #include "chrome/browser/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_wrapper.h"
 #include "chrome/common/chrome_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_types.h"
 #include "content/public/browser/render_process_host.h"
 #include "content/public/browser/render_widget_host.h"
 #include "content/public/browser/web_contents.h"
@@ skipping 34 matching lines @@
 // The default interval in milliseconds to wait before setting the score of
 // currently focused tab.
 const int kFocusedTabScoreAdjustIntervalMs = 500;
 
 // Returns a unique ID for a WebContents.  Do not cast back to a pointer, as
 // the WebContents could be deleted if the user closed the tab.
 int64 IdFromTabContents(WebContents* web_contents) {
   return reinterpret_cast<int64>(web_contents);
 }
 
+////////////////////////////////////////////////////////////////////////////////
+// OomMemoryDetails logs details about all Chrome processes during an out-of-
+// memory event in an attempt to identify the culprit, then discards a tab and
+// deletes itself.
+class OomMemoryDetails : public MemoryDetails {
+ public:
+  OomMemoryDetails();
+
+  // MemoryDetails overrides:
+  virtual void OnDetailsAvailable() OVERRIDE;
+
+ private:
+  virtual ~OomMemoryDetails() {}
+
+  TimeTicks start_time_;
+
+  DISALLOW_COPY_AND_ASSIGN(OomMemoryDetails);
+};
+
+OomMemoryDetails::OomMemoryDetails() {
+  start_time_ = TimeTicks::Now();
+}
+
+void OomMemoryDetails::OnDetailsAvailable() {
+  TimeDelta delta = TimeTicks::Now() - start_time_;
+  // These logs are collected by user feedback reports.  We want them to help
+  // diagnose user-reported problems with frequently discarded tabs.
+  LOG(INFO) << "OOM details (" << delta.InMilliseconds() << " ms):\n"
+      << ToLogString();
+  if (g_browser_process && g_browser_process->oom_priority_manager())
+    g_browser_process->oom_priority_manager()->DiscardTab();
+  // Delete ourselves so we don't have to worry about OomPriorityManager
+  // deleting us when we're still working.
+  delete this;

[Greg Spencer (Chromium), 2012/04/20 00:28:21]

Interesting solution.  I like it.

+}
+
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // OomPriorityManager
 
 OomPriorityManager::TabStats::TabStats()
   : is_pinned(false),
     is_selected(false),
     renderer_handle(0),
     sudden_termination_allowed(false),
@@ skipping 67 matching lines @@
   for (TabStatsList::const_reverse_iterator stats_rit = stats.rbegin();
        stats_rit != stats.rend();
        ++stats_rit) {
     int64 least_important_tab_id = stats_rit->tab_contents_id;
     if (DiscardTabById(least_important_tab_id))
       return true;
   }
   return false;
 }
 
+void OomPriorityManager::LogMemoryAndDiscardTab() {
+  // Deletes itself upon completion.
+  OomMemoryDetails* details = new OomMemoryDetails();
+  details->StartFetch();
+}
+
 bool OomPriorityManager::DiscardTabById(int64 target_web_contents_id) {
   for (BrowserList::const_iterator browser_iterator = BrowserList::begin();
        browser_iterator != BrowserList::end(); ++browser_iterator) {
     Browser* browser = *browser_iterator;
     TabStripModel* model = browser->tabstrip_model();
     for (int idx = 0; idx < model->count(); idx++) {
       // Can't discard tabs that are already discarded.
       if (model->IsTabDiscarded(idx))
         continue;
       WebContents* web_contents = model->GetTabContentsAt(idx)->web_contents();
@@ skipping 250 matching lines @@
         content::ZygoteHost::GetInstance()->AdjustRendererOOMScore(
             iterator->renderer_handle, score);
         pid_to_oom_score_[iterator->renderer_handle] = score;
       }
       priority += priority_increment;
     }
   }
 }
 
 }  // namespace browser