/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.android.server.am;
import java.io.FileOutputStream;
import java.io.IOException;
import android.app.ActivityManager;
import com.android.internal.util.MemInfoReader;
import com.android.server.wm.WindowManagerService;
import android.content.res.Resources;
import android.graphics.Point;
import android.os.SystemProperties;
import android.util.Slog;
import android.view.Display;
/**
* Activity manager code dealing with processes.
*/
final class ProcessList {
// The minimum time we allow between crashes, for us to consider this
// application to be bad and stop and its services and reject broadcasts.
static final int MIN_CRASH_INTERVAL = 60*1000;
// OOM adjustments for processes in various states:
// Adjustment used in certain places where we don't know it yet.
// (Generally this is something that is going to be cached, but we
// don't know the exact value in the cached range to assign yet.)
static final int UNKNOWN_ADJ = 16;
// This is a process only hosting activities that are not visible,
// so it can be killed without any disruption.
static final int CACHED_APP_MAX_ADJ = 15;
static final int CACHED_APP_MIN_ADJ = 9;
// The B list of SERVICE_ADJ -- these are the old and decrepit
// services that aren't as shiny and interesting as the ones in the A list.
static final int SERVICE_B_ADJ = 8;
// This is the process of the previous application that the user was in.
// This process is kept above other things, because it is very common to
// switch back to the previous app. This is important both for recent
// task switch (toggling between the two top recent apps) as well as normal
// UI flow such as clicking on a URI in the e-mail app to view in the browser,
// and then pressing back to return to e-mail.
static final int PREVIOUS_APP_ADJ = 7;
// This is a process holding the home application -- we want to try
// avoiding killing it, even if it would normally be in the background,
// because the user interacts with it so much.
static final int HOME_APP_ADJ = 6;
// This is a process holding an application service -- killing it will not
// have much of an impact as far as the user is concerned.
static final int SERVICE_ADJ = 5;
// This is a process with a heavy-weight application. It is in the
// background, but we want to try to avoid killing it. Value set in
// system/rootdir/init.rc on startup.
static final int HEAVY_WEIGHT_APP_ADJ = 4;
// This is a process currently hosting a backup operation. Killing it
// is not entirely fatal but is generally a bad idea.
static final int BACKUP_APP_ADJ = 3;
// This is a process only hosting components that are perceptible to the
// user, and we really want to avoid killing them, but they are not
// immediately visible. An example is background music playback.
static final int PERCEPTIBLE_APP_ADJ = 2;
// This is a process only hosting activities that are visible to the
// user, so we'd prefer they don't disappear.
static final int VISIBLE_APP_ADJ = 1;
// This is the process running the current foreground app. We'd really
// rather not kill it!
static final int FOREGROUND_APP_ADJ = 0;
// This is a system persistent process, such as telephony. Definitely
// don't want to kill it, but doing so is not completely fatal.
static final int PERSISTENT_PROC_ADJ = -12;
// The system process runs at the default adjustment.
static final int SYSTEM_ADJ = -16;
// Special code for native processes that are not being managed by the system (so
// don't have an oom adj assigned by the system).
static final int NATIVE_ADJ = -17;
// Memory pages are 4K.
static final int PAGE_SIZE = 4*1024;
// The minimum number of cached apps we want to be able to keep around,
// without empty apps being able to push them out of memory.
static final int MIN_CACHED_APPS = 2;
// The maximum number of cached processes we will keep around before killing them.
// NOTE: this constant is *only* a control to not let us go too crazy with
// keeping around processes on devices with large amounts of RAM. For devices that
// are tighter on RAM, the out of memory killer is responsible for killing background
// processes as RAM is needed, and we should *never* be relying on this limit to
// kill them. Also note that this limit only applies to cached background processes;
// we have no limit on the number of service, visible, foreground, or other such
// processes and the number of those processes does not count against the cached
// process limit.
static final int MAX_CACHED_APPS = 24;
// We allow empty processes to stick around for at most 30 minutes.
static final long MAX_EMPTY_TIME = 30*60*1000;
// The maximum number of empty app processes we will let sit around.
private static final int MAX_EMPTY_APPS = computeEmptyProcessLimit(MAX_CACHED_APPS);
// The number of empty apps at which we don't consider it necessary to do
// memory trimming.
static final int TRIM_EMPTY_APPS = MAX_EMPTY_APPS/2;
// The number of cached at which we don't consider it necessary to do
// memory trimming.
static final int TRIM_CACHED_APPS = ((MAX_CACHED_APPS-MAX_EMPTY_APPS)*2)/3;
// Threshold of number of cached+empty where we consider memory critical.
static final int TRIM_CRITICAL_THRESHOLD = 3;
// Threshold of number of cached+empty where we consider memory critical.
static final int TRIM_LOW_THRESHOLD = 5;
// These are the various interesting memory levels that we will give to
// the OOM killer. Note that the OOM killer only supports 6 slots, so we
// can't give it a different value for every possible kind of process.
private final int[] mOomAdj = new int[] {
FOREGROUND_APP_ADJ, VISIBLE_APP_ADJ, PERCEPTIBLE_APP_ADJ,
BACKUP_APP_ADJ, CACHED_APP_MIN_ADJ, CACHED_APP_MAX_ADJ
};
// These are the low-end OOM level limits. This is appropriate for an
// HVGA or smaller phone with less than 512MB. Values are in KB.
private final long[] mOomMinFreeLow = new long[] {
8192, 12288, 16384,
24576, 28672, 32768
};
// These are the high-end OOM level limits. This is appropriate for a
// 1280x800 or larger screen with around 1GB RAM. Values are in KB.
private final long[] mOomMinFreeHigh = new long[] {
49152, 61440, 73728,
86016, 98304, 122880
};
// The actual OOM killer memory levels we are using.
private final long[] mOomMinFree = new long[mOomAdj.length];
private final long mTotalMemMb;
private long mCachedRestoreLevel;
private boolean mHaveDisplaySize;
ProcessList() {
MemInfoReader minfo = new MemInfoReader();
minfo.readMemInfo();
mTotalMemMb = minfo.getTotalSize()/(1024*1024);
updateOomLevels(0, 0, false);
}
void applyDisplaySize(WindowManagerService wm) {
if (!mHaveDisplaySize) {
Point p = new Point();
wm.getBaseDisplaySize(Display.DEFAULT_DISPLAY, p);
if (p.x != 0 && p.y != 0) {
updateOomLevels(p.x, p.y, true);
mHaveDisplaySize = true;
}
}
}
private void updateOomLevels(int displayWidth, int displayHeight, boolean write) {
// Scale buckets from avail memory: at 300MB we use the lowest values to
// 700MB or more for the top values.
float scaleMem = ((float)(mTotalMemMb-300))/(700-300);
// Scale buckets from screen size.
int minSize = 480*800; // 384000
int maxSize = 1280*800; // 1024000 230400 870400 .264
float scaleDisp = ((float)(displayWidth*displayHeight)-minSize)/(maxSize-minSize);
if (false) {
Slog.i("XXXXXX", "scaleMem=" + scaleMem);
Slog.i("XXXXXX", "scaleDisp=" + scaleDisp + " dw=" + displayWidth
+ " dh=" + displayHeight);
}
StringBuilder adjString = new StringBuilder();
StringBuilder memString = new StringBuilder();
float scale = scaleMem > scaleDisp ? scaleMem : scaleDisp;
if (scale < 0) scale = 0;
else if (scale > 1) scale = 1;
int minfree_adj = Resources.getSystem().getInteger(
com.android.internal.R.integer.config_lowMemoryKillerMinFreeKbytesAdjust);
int minfree_abs = Resources.getSystem().getInteger(
com.android.internal.R.integer.config_lowMemoryKillerMinFreeKbytesAbsolute);
if (false) {
Slog.i("XXXXXX", "minfree_adj=" + minfree_adj + " minfree_abs=" + minfree_abs);
}
for (int i=0; i<mOomAdj.length; i++) {
long low = mOomMinFreeLow[i];
long high = mOomMinFreeHigh[i];
mOomMinFree[i] = (long)(low + ((high-low)*scale));
}
if (minfree_abs >= 0) {
for (int i=0; i<mOomAdj.length; i++) {
mOomMinFree[i] = (long)((float)minfree_abs * mOomMinFree[i] / mOomMinFree[mOomAdj.length - 1]);
}
}
if (minfree_adj != 0) {
for (int i=0; i<mOomAdj.length; i++) {
mOomMinFree[i] += (long)((float)minfree_adj * mOomMinFree[i] / mOomMinFree[mOomAdj.length - 1]);
if (mOomMinFree[i] < 0) {
mOomMinFree[i] = 0;
}
}
}
// The maximum size we will restore a process from cached to background, when under
// memory duress, is 1/3 the size we have reserved for kernel caches and other overhead
// before killing background processes.
mCachedRestoreLevel = (getMemLevel(ProcessList.CACHED_APP_MAX_ADJ)/1024) / 3;
for (int i=0; i<mOomAdj.length; i++) {
if (i > 0) {
adjString.append(',');
memString.append(',');
}
adjString.append(mOomAdj[i]);
memString.append((mOomMinFree[i]*1024)/PAGE_SIZE);
}
// Ask the kernel to try to keep enough memory free to allocate 3 full
// screen 32bpp buffers without entering direct reclaim.
int reserve = displayWidth * displayHeight * 4 * 3 / 1024;
int reserve_adj = Resources.getSystem().getInteger(com.android.internal.R.integer.config_extraFreeKbytesAdjust);
int reserve_abs = Resources.getSystem().getInteger(com.android.internal.R.integer.config_extraFreeKbytesAbsolute);
if (reserve_abs >= 0) {
reserve = reserve_abs;
}
if (reserve_adj != 0) {
reserve += reserve_adj;
if (reserve < 0) {
reserve = 0;
}
}
//Slog.i("XXXXXXX", "******************************* MINFREE: " + memString);
if (write) {
writeFile("/sys/module/lowmemorykiller/parameters/adj", adjString.toString());
writeFile("/sys/module/lowmemorykiller/parameters/minfree", memString.toString());
SystemProperties.set("sys.sysctl.extra_free_kbytes", Integer.toString(reserve));
}
// GB: 2048,3072,4096,6144,7168,8192
// HC: 8192,10240,12288,14336,16384,20480
}
public static int computeEmptyProcessLimit(int totalProcessLimit) {
return (totalProcessLimit*2)/3;
}
private static String buildOomTag(String prefix, String space, int val, int base) {
if (val == base) {
if (space == null) return prefix;
return prefix + " ";
}
return prefix + "+" + Integer.toString(val-base);
}
public static String makeOomAdjString(int setAdj) {
if (setAdj >= ProcessList.CACHED_APP_MIN_ADJ) {
return buildOomTag("cch", " ", setAdj, ProcessList.CACHED_APP_MIN_ADJ);
} else if (setAdj >= ProcessList.SERVICE_B_ADJ) {
return buildOomTag("svcb ", null, setAdj, ProcessList.SERVICE_B_ADJ);
} else if (setAdj >= ProcessList.PREVIOUS_APP_ADJ) {
return buildOomTag("prev ", null, setAdj, ProcessList.PREVIOUS_APP_ADJ);
} else if (setAdj >= ProcessList.HOME_APP_ADJ) {
return buildOomTag("home ", null, setAdj, ProcessList.HOME_APP_ADJ);
} else if (setAdj >= ProcessList.SERVICE_ADJ) {
return buildOomTag("svc ", null, setAdj, ProcessList.SERVICE_ADJ);
} else if (setAdj >= ProcessList.HEAVY_WEIGHT_APP_ADJ) {
return buildOomTag("hvy ", null, setAdj, ProcessList.HEAVY_WEIGHT_APP_ADJ);
} else if (setAdj >= ProcessList.BACKUP_APP_ADJ) {
return buildOomTag("bkup ", null, setAdj, ProcessList.BACKUP_APP_ADJ);
} else if (setAdj >= ProcessList.PERCEPTIBLE_APP_ADJ) {
return buildOomTag("prcp ", null, setAdj, ProcessList.PERCEPTIBLE_APP_ADJ);
} else if (setAdj >= ProcessList.VISIBLE_APP_ADJ) {
return buildOomTag("vis ", null, setAdj, ProcessList.VISIBLE_APP_ADJ);
} else if (setAdj >= ProcessList.FOREGROUND_APP_ADJ) {
return buildOomTag("fore ", null, setAdj, ProcessList.FOREGROUND_APP_ADJ);
} else if (setAdj >= ProcessList.PERSISTENT_PROC_ADJ) {
return buildOomTag("pers ", null, setAdj, ProcessList.PERSISTENT_PROC_ADJ);
} else if (setAdj >= ProcessList.SYSTEM_ADJ) {
return buildOomTag("sys ", null, setAdj, ProcessList.SYSTEM_ADJ);
} else if (setAdj >= ProcessList.NATIVE_ADJ) {
return buildOomTag("ntv ", null, setAdj, ProcessList.NATIVE_ADJ);
} else {
return Integer.toString(setAdj);
}
}
public static String makeProcStateString(int curProcState) {
String procState;
switch (curProcState) {
case -1:
procState = "N ";
break;
case ActivityManager.PROCESS_STATE_PERSISTENT:
procState = "P ";
break;
case ActivityManager.PROCESS_STATE_PERSISTENT_UI:
procState = "PU";
break;
case ActivityManager.PROCESS_STATE_TOP:
procState = "T ";
break;
case ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND:
procState = "IF";
break;
case ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND:
procState = "IB";
break;
case ActivityManager.PROCESS_STATE_BACKUP:
procState = "BU";
break;
case ActivityManager.PROCESS_STATE_HEAVY_WEIGHT:
procState = "HW";
break;
case ActivityManager.PROCESS_STATE_SERVICE:
procState = "S ";
break;
case ActivityManager.PROCESS_STATE_RECEIVER:
procState = "R ";
break;
case ActivityManager.PROCESS_STATE_HOME:
procState = "HO";
break;
case ActivityManager.PROCESS_STATE_LAST_ACTIVITY:
procState = "LA";
break;
case ActivityManager.PROCESS_STATE_CACHED_ACTIVITY:
procState = "CA";
break;
case ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT:
procState = "Ca";
break;
case ActivityManager.PROCESS_STATE_CACHED_EMPTY:
procState = "CE";
break;
default:
procState = "??";
break;
}
return procState;
}
public static void appendRamKb(StringBuilder sb, long ramKb) {
for (int j=0, fact=10; j<6; j++, fact*=10) {
if (ramKb < fact) {
sb.append(' ');
}
}
sb.append(ramKb);
}
// The minimum amount of time after a state change it is safe ro collect PSS.
public static final int PSS_MIN_TIME_FROM_STATE_CHANGE = 15*1000;
// The maximum amount of time we want to go between PSS collections.
public static final int PSS_MAX_INTERVAL = 30*60*1000;
// The minimum amount of time between successive PSS requests for *all* processes.
public static final int PSS_ALL_INTERVAL = 10*60*1000;
// The minimum amount of time between successive PSS requests for a process.
private static final int PSS_SHORT_INTERVAL = 2*60*1000;
// The amount of time until PSS when a process first becomes top.
private static final int PSS_FIRST_TOP_INTERVAL = 10*1000;
// The amount of time until PSS when a process first goes into the background.
private static final int PSS_FIRST_BACKGROUND_INTERVAL = 20*1000;
// The amount of time until PSS when a process first becomes cached.
private static final int PSS_FIRST_CACHED_INTERVAL = 30*1000;
// The amount of time until PSS when an important process stays in the same state.
private static final int PSS_SAME_IMPORTANT_INTERVAL = 15*60*1000;
// The amount of time until PSS when a service process stays in the same state.
private static final int PSS_SAME_SERVICE_INTERVAL = 20*60*1000;
// The amount of time until PSS when a cached process stays in the same state.
private static final int PSS_SAME_CACHED_INTERVAL = 30*60*1000;
public static final int PROC_MEM_PERSISTENT = 0;
public static final int PROC_MEM_TOP = 1;
public static final int PROC_MEM_IMPORTANT = 2;
public static final int PROC_MEM_SERVICE = 3;
public static final int PROC_MEM_CACHED = 4;
private static final int[] sProcStateToProcMem = new int[] {
PROC_MEM_PERSISTENT, // ActivityManager.PROCESS_STATE_PERSISTENT
PROC_MEM_PERSISTENT, // ActivityManager.PROCESS_STATE_PERSISTENT_UI
PROC_MEM_TOP, // ActivityManager.PROCESS_STATE_TOP
PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND
PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND
PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_BACKUP
PROC_MEM_IMPORTANT, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT
PROC_MEM_SERVICE, // ActivityManager.PROCESS_STATE_SERVICE
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_RECEIVER
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_HOME
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT
PROC_MEM_CACHED, // ActivityManager.PROCESS_STATE_CACHED_EMPTY
};
private static final long[] sFirstAwakePssTimes = new long[] {
PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT
PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT_UI
PSS_FIRST_TOP_INTERVAL, // ActivityManager.PROCESS_STATE_TOP
PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND
PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND
PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_BACKUP
PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT
PSS_FIRST_BACKGROUND_INTERVAL, // ActivityManager.PROCESS_STATE_SERVICE
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_RECEIVER
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_HOME
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT
PSS_FIRST_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_EMPTY
};
private static final long[] sSameAwakePssTimes = new long[] {
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_PERSISTENT_UI
PSS_SHORT_INTERVAL, // ActivityManager.PROCESS_STATE_TOP
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_FOREGROUND
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_IMPORTANT_BACKGROUND
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_BACKUP
PSS_SAME_IMPORTANT_INTERVAL, // ActivityManager.PROCESS_STATE_HEAVY_WEIGHT
PSS_SAME_SERVICE_INTERVAL, // ActivityManager.PROCESS_STATE_SERVICE
PSS_SAME_SERVICE_INTERVAL, // ActivityManager.PROCESS_STATE_RECEIVER
PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_HOME
PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_LAST_ACTIVITY
PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY
PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_ACTIVITY_CLIENT
PSS_SAME_CACHED_INTERVAL, // ActivityManager.PROCESS_STATE_CACHED_EMPTY
};
public static boolean procStatesDifferForMem(int procState1, int procState2) {
return sProcStateToProcMem[procState1] != sProcStateToProcMem[procState2];
}
public static long computeNextPssTime(int procState, boolean first, boolean sleeping,
long now) {
final long[] table = sleeping
? (first
? sFirstAwakePssTimes
: sSameAwakePssTimes)
: (first
? sFirstAwakePssTimes
: sSameAwakePssTimes);
return now + table[procState];
}
long getMemLevel(int adjustment) {
for (int i=0; i<mOomAdj.length; i++) {
if (adjustment <= mOomAdj[i]) {
return mOomMinFree[i] * 1024;
}
}
return mOomMinFree[mOomAdj.length-1] * 1024;
}
/**
* Return the maximum pss size in kb that we consider a process acceptable to
* restore from its cached state for running in the background when RAM is low.
*/
long getCachedRestoreThresholdKb() {
return mCachedRestoreLevel;
}
private void writeFile(String path, String data) {
FileOutputStream fos = null;
try {
fos = new FileOutputStream(path);
fos.write(data.getBytes());
} catch (IOException e) {
Slog.w(ActivityManagerService.TAG, "Unable to write " + path);
} finally {
if (fos != null) {
try {
fos.close();
} catch (IOException e) {
}
}
}
}
}