1 /* 2 * Copyright (C) 2011 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 package com.android.internal.util; 18 19 import android.compat.annotation.UnsupportedAppUsage; 20 import android.os.Build; 21 import android.os.Debug; 22 import android.os.StrictMode; 23 24 public final class MemInfoReader { 25 final long[] mInfos = new long[Debug.MEMINFO_COUNT]; 26 27 @UnsupportedAppUsage MemInfoReader()28 public MemInfoReader() { 29 } 30 31 @UnsupportedAppUsage readMemInfo()32 public void readMemInfo() { 33 // Permit disk reads here, as /proc/meminfo isn't really "on 34 // disk" and should be fast. TODO: make BlockGuard ignore 35 // /proc/ and /sys/ files perhaps? 36 StrictMode.ThreadPolicy savedPolicy = StrictMode.allowThreadDiskReads(); 37 try { 38 Debug.getMemInfo(mInfos); 39 } finally { 40 StrictMode.setThreadPolicy(savedPolicy); 41 } 42 } 43 44 /** 45 * Total amount of RAM available to the kernel. 46 */ 47 @UnsupportedAppUsage getTotalSize()48 public long getTotalSize() { 49 return mInfos[Debug.MEMINFO_TOTAL] * 1024; 50 } 51 52 /** 53 * Amount of RAM that is not being used for anything. 54 */ 55 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) getFreeSize()56 public long getFreeSize() { 57 return mInfos[Debug.MEMINFO_FREE] * 1024; 58 } 59 60 /** 61 * Amount of RAM that the kernel is being used for caches, not counting caches 62 * that are mapped in to processes. 63 */ 64 @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.R, trackingBug = 170729553) getCachedSize()65 public long getCachedSize() { 66 return getCachedSizeKb() * 1024; 67 } 68 69 /** 70 * Amount of RAM that is in use by the kernel for actual allocations. 71 */ getKernelUsedSize()72 public long getKernelUsedSize() { 73 return getKernelUsedSizeKb() * 1024; 74 } 75 76 /** 77 * Total amount of RAM available to the kernel. 78 */ getTotalSizeKb()79 public long getTotalSizeKb() { 80 return mInfos[Debug.MEMINFO_TOTAL]; 81 } 82 83 /** 84 * Amount of RAM that is not being used for anything. 85 */ getFreeSizeKb()86 public long getFreeSizeKb() { 87 return mInfos[Debug.MEMINFO_FREE]; 88 } 89 90 /** 91 * Amount of RAM that the kernel is being used for caches, not counting caches 92 * that are mapped in to processes. 93 */ getCachedSizeKb()94 public long getCachedSizeKb() { 95 long kReclaimable = mInfos[Debug.MEMINFO_KRECLAIMABLE]; 96 97 // Note: MEMINFO_KRECLAIMABLE includes MEMINFO_SLAB_RECLAIMABLE and ION pools. 98 // Fall back to using MEMINFO_SLAB_RECLAIMABLE in case of older kernels that do 99 // not include KReclaimable meminfo field. 100 if (kReclaimable == 0) { 101 kReclaimable = mInfos[Debug.MEMINFO_SLAB_RECLAIMABLE]; 102 } 103 return mInfos[Debug.MEMINFO_BUFFERS] + kReclaimable 104 + mInfos[Debug.MEMINFO_CACHED] - mInfos[Debug.MEMINFO_MAPPED]; 105 } 106 107 /** 108 * Amount of RAM that is in use by the kernel for actual allocations. 109 */ getKernelUsedSizeKb()110 public long getKernelUsedSizeKb() { 111 long size = mInfos[Debug.MEMINFO_SHMEM] + mInfos[Debug.MEMINFO_SLAB_UNRECLAIMABLE] 112 + mInfos[Debug.MEMINFO_VM_ALLOC_USED] + mInfos[Debug.MEMINFO_PAGE_TABLES]; 113 if (!Debug.isVmapStack()) { 114 size += mInfos[Debug.MEMINFO_KERNEL_STACK]; 115 } 116 return size; 117 } 118 getSwapTotalSizeKb()119 public long getSwapTotalSizeKb() { 120 return mInfos[Debug.MEMINFO_SWAP_TOTAL]; 121 } 122 getSwapFreeSizeKb()123 public long getSwapFreeSizeKb() { 124 return mInfos[Debug.MEMINFO_SWAP_FREE]; 125 } 126 getZramTotalSizeKb()127 public long getZramTotalSizeKb() { 128 return mInfos[Debug.MEMINFO_ZRAM_TOTAL]; 129 } 130 131 @UnsupportedAppUsage getRawInfo()132 public long[] getRawInfo() { 133 return mInfos; 134 } 135 } 136