1 // Copyright 2014 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #include "athena/resource_manager/public/resource_manager_delegate.h" 6 7 #include <string> 8 9 #include "base/logging.h" 10 #include "base/macros.h" 11 #include "base/process/process_metrics.h" 12 13 namespace athena { 14 15 namespace { 16 // This is the minimum amount of time in milliseconds between checks for 17 // memory pressure. 18 const int kMemoryPressureIntervalMs = 750; 19 } // namespace 20 21 class ResourceManagerDelegateImpl : public ResourceManagerDelegate { 22 public: ResourceManagerDelegateImpl()23 ResourceManagerDelegateImpl() {} ~ResourceManagerDelegateImpl()24 virtual ~ResourceManagerDelegateImpl() {} 25 26 private: GetUsedMemoryInPercent()27 virtual int GetUsedMemoryInPercent() OVERRIDE { 28 base::SystemMemoryInfoKB info; 29 if (!base::GetSystemMemoryInfo(&info)) { 30 LOG(WARNING) << "Cannot determine the free memory of the system."; 31 return 0; 32 } 33 // TODO(skuhne): Instead of adding the kernel memory pressure calculation 34 // logic here, we should have a kernel mechanism similar to the low memory 35 // notifier in ChromeOS which offers multiple pressure states. 36 // To track this, we have crbug.com/381196. 37 38 // The available memory consists of "real" and virtual (z)ram memory. 39 // Since swappable memory uses a non pre-deterministic compression and 40 // the compression creates its own "dynamic" in the system, it gets 41 // de-emphasized by the |kSwapWeight| factor. 42 const int kSwapWeight = 4; 43 44 // The total memory we have is the "real memory" plus the virtual (z)ram. 45 int total_memory = info.total + info.swap_total / kSwapWeight; 46 47 // The kernel internally uses 50MB. 48 const int kMinFileMemory = 50 * 1024; 49 50 // Most file memory can be easily reclaimed. 51 int file_memory = info.active_file + info.inactive_file; 52 // unless it is dirty or it's a minimal portion which is required. 53 file_memory -= info.dirty + kMinFileMemory; 54 55 // Available memory is the sum of free, swap and easy reclaimable memory. 56 int available_memory = 57 info.free + info.swap_free / kSwapWeight + file_memory; 58 59 DCHECK(available_memory < total_memory); 60 int percentage = ((total_memory - available_memory) * 100) / total_memory; 61 return percentage; 62 } 63 MemoryPressureIntervalInMS()64 virtual int MemoryPressureIntervalInMS() OVERRIDE { 65 return kMemoryPressureIntervalMs; 66 } 67 DISALLOW_COPY_AND_ASSIGN(ResourceManagerDelegateImpl); 68 }; 69 70 // static 71 ResourceManagerDelegate* CreateResourceManagerDelegate()72ResourceManagerDelegate::CreateResourceManagerDelegate() { 73 return new ResourceManagerDelegateImpl; 74 } 75 76 } // namespace athena 77