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.server.am; 18 19 import java.io.FileOutputStream; 20 import java.io.IOException; 21 22 import android.app.ActivityManager; 23 import com.android.internal.util.MemInfoReader; 24 import com.android.server.wm.WindowManagerService; 25 26 import android.content.res.Resources; 27 import android.graphics.Point; 28 import android.os.SystemProperties; 29 import android.util.Slog; 30 import android.view.Display; 31 32 /** 33 * Activity manager code dealing with processes. 34 */ 35 final class ProcessList { 36 // The minimum time we allow between crashes, for us to consider this 37 // application to be bad and stop and its services and reject broadcasts. 38 static final int MIN_CRASH_INTERVAL = 60*1000; 39 40 // OOM adjustments for processes in various states: 41 42 // Adjustment used in certain places where we don't know it yet. 43 // (Generally this is something that is going to be cached, but we 44 // don't know the exact value in the cached range to assign yet.) 45 static final int UNKNOWN_ADJ = 16; 46 47 // This is a process only hosting activities that are not visible, 48 // so it can be killed without any disruption. 49 static final int CACHED_APP_MAX_ADJ = 15; 50 static final int CACHED_APP_MIN_ADJ = 9; 51 52 // The B list of SERVICE_ADJ -- these are the old and decrepit 53 // services that aren't as shiny and interesting as the ones in the A list. 54 static final int SERVICE_B_ADJ = 8; 55 56 // This is the process of the previous application that the user was in. 57 // This process is kept above other things, because it is very common to 58 // switch back to the previous app. This is important both for recent 59 // task switch (toggling between the two top recent apps) as well as normal 60 // UI flow such as clicking on a URI in the e-mail app to view in the browser, 61 // and then pressing back to return to e-mail. 62 static final int PREVIOUS_APP_ADJ = 7; 63 64 // This is a process holding the home application -- we want to try 65 // avoiding killing it, even if it would normally be in the background, 66 // because the user interacts with it so much. 67 static final int HOME_APP_ADJ = 6; 68 69 // This is a process holding an application service -- killing it will not 70 // have much of an impact as far as the user is concerned. 71 static final int SERVICE_ADJ = 5; 72 73 // This is a process with a heavy-weight application. It is in the 74 // background, but we want to try to avoid killing it. Value set in 75 // system/rootdir/init.rc on startup. 76 static final int HEAVY_WEIGHT_APP_ADJ = 4; 77 78 // This is a process currently hosting a backup operation. Killing it 79 // is not entirely fatal but is generally a bad idea. 80 static final int BACKUP_APP_ADJ = 3; 81 82 // This is a process only hosting components that are perceptible to the 83 // user, and we really want to avoid killing them, but they are not 84 // immediately visible. An example is background music playback. 85 static final int PERCEPTIBLE_APP_ADJ = 2; 86 87 // This is a process only hosting activities that are visible to the 88 // user, so we'd prefer they don't disappear. 89 static final int VISIBLE_APP_ADJ = 1; 90 91 // This is the process running the current foreground app. We'd really 92 // rather not kill it! 93 static final int FOREGROUND_APP_ADJ = 0; 94 95 // This is a system persistent process, such as telephony. Definitely 96 // don't want to kill it, but doing so is not completely fatal. 97 static final int PERSISTENT_PROC_ADJ = -12; 98 99 // The system process runs at the default adjustment. 100 static final int SYSTEM_ADJ = -16; 101 102 // Special code for native processes that are not being managed by the system (so 103 // don't have an oom adj assigned by the system). 104 static final int NATIVE_ADJ = -17; 105 106 // Memory pages are 4K. 107 static final int PAGE_SIZE = 4*1024; 108 109 // The minimum number of cached apps we want to be able to keep around, 110 // without empty apps being able to push them out of memory. 111 static final int MIN_CACHED_APPS = 2; 112 113 // The maximum number of cached processes we will keep around before killing them. 114 // NOTE: this constant is *only* a control to not let us go too crazy with 115 // keeping around processes on devices with large amounts of RAM. For devices that 116 // are tighter on RAM, the out of memory killer is responsible for killing background 117 // processes as RAM is needed, and we should *never* be relying on this limit to 118 // kill them. Also note that this limit only applies to cached background processes; 119 // we have no limit on the number of service, visible, foreground, or other such 120 // processes and the number of those processes does not count against the cached 121 // process limit. 122 static final int MAX_CACHED_APPS = 24; 123 124 // We allow empty processes to stick around for at most 30 minutes. 125 static final long MAX_EMPTY_TIME = 30*60*1000; 126 127 // The maximum number of empty app processes we will let sit around. 128 private static final int MAX_EMPTY_APPS = computeEmptyProcessLimit(MAX_CACHED_APPS); 129 130 // The number of empty apps at which we don't consider it necessary to do 131 // memory trimming. 132 static final int TRIM_EMPTY_APPS = MAX_EMPTY_APPS/2; 133 134 // The number of cached at which we don't consider it necessary to do 135 // memory trimming. 136 static final int TRIM_CACHED_APPS = ((MAX_CACHED_APPS-MAX_EMPTY_APPS)*2)/3; 137 138 // Threshold of number of cached+empty where we consider memory critical. 139 static final int TRIM_CRITICAL_THRESHOLD = 3; 140 141 // Threshold of number of cached+empty where we consider memory critical. 142 static final int TRIM_LOW_THRESHOLD = 5; 143 144 // These are the various interesting memory levels that we will give to 145 // the OOM killer. Note that the OOM killer only supports 6 slots, so we 146 // can't give it a different value for every possible kind of process. 147 private final int[] mOomAdj = new int[] { 148 FOREGROUND_APP_ADJ, VISIBLE_APP_ADJ, PERCEPTIBLE_APP_ADJ, 149 BACKUP_APP_ADJ, CACHED_APP_MIN_ADJ, CACHED_APP_MAX_ADJ 150 }; 151 // These are the low-end OOM level limits. This is appropriate for an 152 // HVGA or smaller phone with less than 512MB. Values are in KB. 153 private final long[] mOomMinFreeLow = new long[] { 154 8192, 12288, 16384, 155 24576, 28672, 32768 156 }; 157 // These are the high-end OOM level limits. This is appropriate for a 158 // 1280x800 or larger screen with around 1GB RAM. Values are in KB. 159 private final long[] mOomMinFreeHigh = new long[] { 160 49152, 61440, 73728, 161 86016, 98304, 122880 162 }; 163 // The actual OOM killer memory levels we are using. 164 private final long[] mOomMinFree = new long[mOomAdj.length]; 165 166 private final long mTotalMemMb; 167 168 private long mCachedRestoreLevel; 169 170 private boolean mHaveDisplaySize; 171 172 ProcessList() { 173 MemInfoReader minfo = new MemInfoReader(); 174 minfo.readMemInfo(); 175 mTotalMemMb = minfo.getTotalSize()/(1024*1024); 176 updateOomLevels(0, 0, false); 177 } 178 179 void applyDisplaySize(WindowManagerService wm) { 180 if (!mHaveDisplaySize) { 181 Point p = new Point(); 182 wm.getBaseDisplaySize(Display.DEFAULT_DISPLAY, p); 183 if (p.x != 0 && p.y != 0) { 184 updateOomLevels(p.x, p.y, true); 185 mHaveDisplaySize = true; 186 } 187 } 188 } 189 190 private void updateOomLevels(int displayWidth, int displayHeight, boolean write) { 191 // Scale buckets from avail memory: at 300MB we use the lowest values to 192 // 700MB or more for the top values. 193 float scaleMem = ((float)(mTotalMemMb-300))/(700-300); 194 195 // Scale buckets from screen size. 196 int minSize = 480*800; // 384000 197 int maxSize = 1280*800; // 1024000 230400 870400 .264 198 float scaleDisp = ((float)(displayWidth*displayHeight)-minSize)/(maxSize-minSize); 199 if (false) { 200 Slog.i("XXXXXX", "scaleMem=" + scaleMem); 201 Slog.i("XXXXXX", "scaleDisp=" + scaleDisp + " dw=" + displayWidth 202 + " dh=" + displayHeight); 203 } 204 205 StringBuilder adjString = new StringBuilder(); 206 StringBuilder memString = new StringBuilder(); 207 208 float scale = scaleMem > scaleDisp ? scaleMem : scaleDisp; 209 if (scale < 0) scale = 0; 210 else if (scale > 1) scale = 1; 211 int minfree_adj = Resources.getSystem().getInteger( 212 com.android.internal.R.integer.config_lowMemoryKillerMinFreeKbytesAdjust); 213 int minfree_abs = Resources.getSystem().getInteger( 214 com.android.internal.R.integer.config_lowMemoryKillerMinFreeKbytesAbsolute); 215 if (false) { 216 Slog.i("XXXXXX", "minfree_adj=" + minfree_adj + " minfree_abs=" + minfree_abs); 217 } 218 219 for (int i=0; i<mOomAdj.length; i++) { 220 long low = mOomMinFreeLow[i]; 221 long high = mOomMinFreeHigh[i]; 222 mOomMinFree[i] = (long)(low + ((high-low)*scale)); 223 } 224 225 if (minfree_abs >= 0) { 226 for (int i=0; i<mOomAdj.length; i++) { 227 mOomMinFree[i] = (long)((float)minfree_abs * mOomMinFree[i] / mOomMinFree[mOomAdj.length - 1]); 228 } 229 } 230 231 if (minfree_adj != 0) { 232 for (int i=0; i<mOomAdj.length; i++) { 233 mOomMinFree[i] += (long)((float)minfree_adj * mOomMinFree[i] / mOomMinFree[mOomAdj.length - 1]); 234 if (mOomMinFree[i] < 0) { 235 mOomMinFree[i] = 0; 236 } 237 } 238 } 239 240 // The maximum size we will restore a process from cached to background, when under 241 // memory duress, is 1/3 the size we have reserved for kernel caches and other overhead 242 // before killing background processes. 243 mCachedRestoreLevel = (getMemLevel(ProcessList.CACHED_APP_MAX_ADJ)/1024) / 3; 244 245 for (int i=0; i<mOomAdj.length; i++) { 246 if (i > 0) { 247 adjString.append(','); 248 memString.append(','); 249 } 250 adjString.append(mOomAdj[i]); 251 memString.append((mOomMinFree[i]*1024)/PAGE_SIZE); 252 } 253 254 // Ask the kernel to try to keep enough memory free to allocate 3 full 255 // screen 32bpp buffers without entering direct reclaim. 256 int reserve = displayWidth * displayHeight * 4 * 3 / 1024; 257 int reserve_adj = Resources.getSystem().getInteger(com.android.internal.R.integer.config_extraFreeKbytesAdjust); 258 int reserve_abs = Resources.getSystem().getInteger(com.android.internal.R.integer.config_extraFreeKbytesAbsolute); 259 260 if (reserve_abs >= 0) { 261 reserve = reserve_abs; 262 } 263 264 if (reserve_adj != 0) { 265 reserve += reserve_adj; 266 if (reserve < 0) { 267 reserve = 0; 268 } 269 } 270 271 //Slog.i("XXXXXXX", "******************************* MINFREE: " + memString); 272 if (write) { 273 writeFile("/sys/module/lowmemorykiller/parameters/adj", adjString.toString()); 274 writeFile("/sys/module/lowmemorykiller/parameters/minfree", memString.toString()); 275 SystemProperties.set("sys.sysctl.extra_free_kbytes", Integer.toString(reserve)); 276 } 277 // GB: 2048,3072,4096,6144,7168,8192 278 // HC: 8192,10240,12288,14336,16384,20480 279 } 280 281 public static int computeEmptyProcessLimit(int totalProcessLimit) { 282 return (totalProcessLimit*2)/3; 283 } 284 285 private static String buildOomTag(String prefix, String space, int val, int base) { 286 if (val == base) { 287 if (space == null) return prefix; 288 return prefix + " "; 289 } 290 return prefix + "+" + Integer.toString(val-base); 291 } 292 293 public static String makeOomAdjString(int setAdj) { 294 if (setAdj >= ProcessList.CACHED_APP_MIN_ADJ) { 295 return buildOomTag("cch", " ", setAdj, ProcessList.CACHED_APP_MIN_ADJ); 296 } else if (setAdj >= ProcessList.SERVICE_B_ADJ) { 297 return buildOomTag("svcb ", null, setAdj, ProcessList.SERVICE_B_ADJ); 298 } else if (setAdj >= ProcessList.PREVIOUS_APP_ADJ) { 299 return buildOomTag("prev ", null, setAdj, ProcessList.PREVIOUS_APP_ADJ); 300 } else if (setAdj >= ProcessList.HOME_APP_ADJ) { 301 return buildOomTag("home ", null, setAdj, ProcessList.HOME_APP_ADJ); 302 } else if (setAdj >= ProcessList.SERVICE_ADJ) { 303 return buildOomTag("svc ", null, setAdj, ProcessList.SERVICE_ADJ); 304 } else if (setAdj >= ProcessList.HEAVY_WEIGHT_APP_ADJ) { 305 return buildOomTag("hvy ", null, setAdj, ProcessList.HEAVY_WEIGHT_APP_ADJ); 306 } else if (setAdj >= ProcessList.BACKUP_APP_ADJ) { 307 return buildOomTag("bkup ", null, setAdj, ProcessList.BACKUP_APP_ADJ); 308 } else if (setAdj >= ProcessList.PERCEPTIBLE_APP_ADJ) { 309 return buildOomTag("prcp ", null, setAdj, ProcessList.PERCEPTIBLE_APP_ADJ); 310 } else if (setAdj >= ProcessList.VISIBLE_APP_ADJ) { 311 return buildOomTag("vis ", null, setAdj, ProcessList.VISIBLE_APP_ADJ); 312 } else if (setAdj >= ProcessList.FOREGROUND_APP_ADJ) { 313 return buildOomTag("fore ", null, setAdj, ProcessList.FOREGROUND_APP_ADJ); 314 } else if (setAdj >= ProcessList.PERSISTENT_PROC_ADJ) { 315 return buildOomTag("pers ", null, setAdj, ProcessList.PERSISTENT_PROC_ADJ); 316 } else if (setAdj >= ProcessList.SYSTEM_ADJ) { 317 return buildOomTag("sys ", null, setAdj, ProcessList.SYSTEM_ADJ); 318 } else if (setAdj >= ProcessList.NATIVE_ADJ) { 319 return buildOomTag("ntv ", null, setAdj, ProcessList.NATIVE_ADJ); 320 } else { 321 return Integer.toString(setAdj); 322 } 323 } 324 325 public static String makeProcStateString(int curProcState) { 326 String procState; 327 switch (curProcState) { 328 case -1: 329 procState = "N "; 330 break; 331 case ActivityManager.PROCESS_STATE_PERSISTENT: 332 procState = "P "; 333 break; 334 case ActivityManager.PROCESS_STATE_PERSISTENT_UI: 335 procState = "PU"; 336 break; 337 case ActivityManager.PROCESS_STATE_TOP: 338 procState = "T "; 339 break; 340 case ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND: 341 procState = "IF"; 342 break; 343 case ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND: 344 procState = "IB"; 345 break; 346 case ActivityManager.PROCESS_STATE_BACKUP: 347 procState = "BU"; 348 break; 349 case ActivityManager.PROCESS_STATE_HEAVY_WEIGHT: 350 procState = "HW"; 351 break; 352 case ActivityManager.PROCESS_STATE_SERVICE: 353 procState = "S "; 354 break; 355 case ActivityManager.PROCESS_STATE_RECEIVER: 356 procState = "R "; 357 break; 358 case ActivityManager.PROCESS_STATE_HOME: 359 procState = "HO"; 360 break; 361 case ActivityManager.PROCESS_STATE_LAST_ACTIVITY: 362 procState = "LA"; 363 break; 364 case ActivityManager.PROCESS_STATE_CACHED_ACTIVITY: 365 procState = "CA"; 366 break; 367 case ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT: 368 procState = "Ca"; 369 break; 370 case ActivityManager.PROCESS_STATE_CACHED_EMPTY: 371 procState = "CE"; 372 break; 373 default: 374 procState = "??"; 375 break; 376 } 377 return procState; 378 } 379 380 public static void appendRamKb(StringBuilder sb, long ramKb) { 381 for (int j=0, fact=10; j<6; j++, fact*=10) { 382 if (ramKb < fact) { 383 sb.append(' '); 384 } 385 } 386 sb.append(ramKb); 387 } 388 389 // The minimum amount of time after a state change it is safe ro collect PSS. 390 public static final int PSS_MIN_TIME_FROM_STATE_CHANGE = 15*1000; 391 392 // The maximum amount of time we want to go between PSS collections. 393 public static final int PSS_MAX_INTERVAL = 30*60*1000; 394 395 // The minimum amount of time between successive PSS requests for *all* processes. 396 public static final int PSS_ALL_INTERVAL = 10*60*1000; 397 398 // The minimum amount of time between successive PSS requests for a process. 399 private static final int PSS_SHORT_INTERVAL = 2*60*1000; 400 401 // The amount of time until PSS when a process first becomes top. 402 private static final int PSS_FIRST_TOP_INTERVAL = 10*1000; 403 404 // The amount of time until PSS when a process first goes into the background. 405 private static final int PSS_FIRST_BACKGROUND_INTERVAL = 20*1000; 406 407 // The amount of time until PSS when a process first becomes cached. 408 private static final int PSS_FIRST_CACHED_INTERVAL = 30*1000; 409 410 // The amount of time until PSS when an important process stays in the same state. 411 private static final int PSS_SAME_IMPORTANT_INTERVAL = 15*60*1000; 412 413 // The amount of time until PSS when a service process stays in the same state. 414 private static final int PSS_SAME_SERVICE_INTERVAL = 20*60*1000; 415 416 // The amount of time until PSS when a cached process stays in the same state. 417 private static final int PSS_SAME_CACHED_INTERVAL = 30*60*1000; 418 419 public static final int PROC_MEM_PERSISTENT = 0; 420 public static final int PROC_MEM_TOP = 1; 421 public static final int PROC_MEM_IMPORTANT = 2; 422 public static final int PROC_MEM_SERVICE = 3; 423 public static final int PROC_MEM_CACHED = 4; 424 425 private static final int[] sProcStateToProcMem = new int[] { 426 PROC_MEM_PERSISTENT, // ActivityManager.PROCESS_STATE_PERSISTENT 427 PROC_MEM_PERSISTENT, // ActivityManager.PROCESS_STATE_PERSISTENT_UI 428 PROC_MEM_TOP, // ActivityManager.PROCESS_STATE_TOP 429 PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND 430 PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND 431 PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_BACKUP 432 PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT 433 PROC_MEM_SERVICE, // ActivityManager.PROCESS_STATE_SERVICE 434 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_RECEIVER 435 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_HOME 436 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY 437 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY 438 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT 439 PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_EMPTY 440 }; 441 442 private static final long[] sFirstAwakePssTimes = new long[] { 443 PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT 444 PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT_UI 445 PSS_FIRST_TOP_INTERVAL, // ActivityManager.PROCESS_STATE_TOP 446 PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND 447 PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND 448 PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_BACKUP 449 PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT 450 PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_SERVICE 451 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_RECEIVER 452 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_HOME 453 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY 454 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY 455 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT 456 PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_EMPTY 457 }; 458 459 private static final long[] sSameAwakePssTimes = new long[] { 460 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT 461 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT_UI 462 PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_TOP 463 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND 464 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND 465 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_BACKUP 466 PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT 467 PSS_SAME_SERVICE_INTERVAL, // ActivityManager.PROCESS_STATE_SERVICE 468 PSS_SAME_SERVICE_INTERVAL, // ActivityManager.PROCESS_STATE_RECEIVER 469 PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_HOME 470 PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY 471 PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY 472 PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT 473 PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_EMPTY 474 }; 475 476 public static boolean procStatesDifferForMem(int procState1, int procState2) { 477 return sProcStateToProcMem[procState1] != sProcStateToProcMem[procState2]; 478 } 479 480 public static long computeNextPssTime(int procState, boolean first, boolean sleeping, 481 long now) { 482 final long[] table = sleeping 483 ? (first 484 ? sFirstAwakePssTimes 485 : sSameAwakePssTimes) 486 : (first 487 ? sFirstAwakePssTimes 488 : sSameAwakePssTimes); 489 return now + table[procState]; 490 } 491 492 long getMemLevel(int adjustment) { 493 for (int i=0; i<mOomAdj.length; i++) { 494 if (adjustment <= mOomAdj[i]) { 495 return mOomMinFree[i] * 1024; 496 } 497 } 498 return mOomMinFree[mOomAdj.length-1] * 1024; 499 } 500 501 /** 502 * Return the maximum pss size in kb that we consider a process acceptable to 503 * restore from its cached state for running in the background when RAM is low. 504 */ 505 long getCachedRestoreThresholdKb() { 506 return mCachedRestoreLevel; 507 } 508 509 private void writeFile(String path, String data) { 510 FileOutputStream fos = null; 511 try { 512 fos = new FileOutputStream(path); 513 fos.write(data.getBytes()); 514 } catch (IOException e) { 515 Slog.w(ActivityManagerService.TAG, "Unable to write " + path); 516 } finally { 517 if (fos != null) { 518 try { 519 fos.close(); 520 } catch (IOException e) { 521 } 522 } 523 } 524 } 525 } 526
