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标题: 常见的debug [打印本页]

作者: 赖振军 时间: 2016-7-21 18:03
标题: 常见的debug

Android基本debug手法

1. KK/build/envsetup.sh

a) lunch

b) croot

c) cgrep: Greps on all local C/C++ files.

d) jgrep: Greps on all local Java files

e) resgrep: Greps on all localres/*.xml files

2. init.tvserver.sh

if [ ! -e/system/rtk_rootfs/usr/local/etc/dvdplayer/noaplogprint ]; then

cd /system/rtk_rootfs/usr/local/bin;./RootApp TvServer > /dev/c**ole 2>&1 &

else

cd /system/rtk_rootfs/usr/local/bin;./RootApp TvServer > /dev/c**ole 1>/dev/null &

cd /system/rtk_rootfs/usr/local/bin; logwrapper ./RootApp TvServer&

b) 有需要开机执行的命令或脚本可以加在这个shell里面

Eg: factory load

3. exec background logcat

logcat –v time> /scard/logcat.txt &

4. /data/system/packages.xml

a) packages.xml里面记录了系统当中安装的APK的所有属性，权限等信息。当系统中的APK安装、删除、升级时，文件就会被更新

root@android:/data/system# cat packages.xml | grep homeshell

package name="com.yunos.tv.homeshell"

codePath="/system/app/AliTvHomeshell.apk"nativeLibraryPath="/data/app-lib/AliTvHomeshell"

flags="572997"

ft="15419d30f18"

it="15419d30f18"

ut="15419d30f18"

version="2101090103"

userId="10030"

b) dumpsys package 包名 | grepversion

root@android:/ # dumpsys package com.yunos.tv.homeshell | grepversion

versionCode=2101090103targetSdk=22

versionName=DVB_TV_HOME_HKC_Metro_1.9.1.03_R

5. 关闭/打开DirectVO

a) 关闭DVO

setprop media.sf.enable_vo 0

setprop media.sf.enable_vo_zero_copy 0

b) 打开DVO

setprop media.sf.enable_vo 1

setprop media.sf.enable_vo_zero_copy 1

6. dumpsys SurfaceFlinger

a) 当遇到画面显示比例异常或者画面卡住时，异常状态下输入cmd “dumpsys SurfaceFlinger

”

+ Layer 0xb88b8140(SurfaceView)

Region transparentRegion (this=0xb88b82c8,count=1)

[ 0, 0, 0, 0]

Region visibleRegion (this=0xb88b8148,count=1)

[ 0, 88, 1280, 631]

layerStack= 0, z= 21015, pos=(0,88), size=(1280, 543), crop=( 0, 0,1280, 543), isOpaque=1, invalidate=0, alpha=0xff, flags=0x00000000,tr=[1.00, 0.00][0.00, 1.00]

client=0xb88b50e8

format= 4, activeBuffer=[1024x576:1280,32315659], queued-frames=0, mRefreshPending=0

mTexName=55586330 mCurrentTexture=0

mCurrentCrop=[0,0,1024,576]mCurrentTransform=0

mAbandoned=0

-BufferQueuemMaxAcquiredBufferCount=1, mDequeueBufferCannotBlock=0,default-size=[1280x543], default-format=4, transform-hint=00, FIFO(0)={}

>[00:0xb88a2e18] state=ACQUIRED,0xb88beb80 [1024x 576:1280,32315659]

[01:0xb88be4e0] state=DEQUEUED,0xb88bcf80 [1024x 576:1280,32315659]

[02:0xb88b7758] state=DEQUEUED,0xb88a30f8 [1024x 576:1280,32315659]

ACQUIRED: 这个是目前在show的画面

DEQUEUED: 这个是producerhold住的buffer,准备用来写如decode之后的data

QUEUED：这个是一张ready的画面,可以由c**umer拿去show

如果可以正常往下走的话,应该是

quequed的那一张变成acquired,

acquired的那一张变成free,

dequeued那一张由omx写进decode之后的data后变成queued.

b) 遇到画面显示比例异常时还可以使用Eclipse DDMS中的”dump View Hierarchy for UI Automator”工具

7. Open video fw/audio fw/kernellog

a) Open video f/w log

touch /data/realtek/ videodebug

b) Open audio f/w log

touch /data/realtek/ audiodebug

c) Open kernel log

touch /data/realtek/kerneldebug

d) How to adjust kernel logpriority

echo 8 > /proc/sys/kernel/printk

8. Lowmemorykiller

low memory killer就是在系统内存低于某值时，清除相关的程序，保障系统保持拥有一定数量的空闲内存

Lowmemorykiller根据三个参数来决定哪个进程需要被kill掉 : oom_adj/minfree/cache memory

a) 130|root@android:/ # cat/etc/lowmemorykiller.txt

adj:0,1,2,3,9,15

#need divfor each element

minfree:1536,2048,4096,8192,11520,19200

130|root@android:/# cat /sys/module/lowmemorykiller/parameters/adj

0,58,117,176,529,1000

130|root@android:/# cat /sys/module/lowmemorykiller/parameters/minfree

1536,2048,4096,8192,11520,19200

PS: minfree以page为单位，所以实际大小要乘以4

b) 进程优先级 ( oom_adj )

/kernel/android/KK/frameworks/base/services/java/com/android/server/am/ProcessList.java

// This is a process only hosting activities that are not visible,

// so it can be killed without any disruption.

staticfinal int CACHED_APP_MAX_ADJ = 15;

static final int CACHED_APP_MIN_ADJ = 9;

// Thisis a process holding an application service -- killing it will not

// have much of an impact as far as theuser is concerned.

static final int SERVICE_ADJ = 5;

// This is a process with a heavy-weightapplication. It is in the

// background, but we want to try to avoidkilling it. Value set in

// system/rootdir/init.rc on startup.

static final int HEAVY_WEIGHT_APP_ADJ = 4;

// This is a process currently hosting abackup operation. Killing it

// is not entirely fatal but is generally abad idea.

static final int BACKUP_APP_ADJ = 3;

// This is a process only hosting componentsthat are perceptible to the

// user, and we really want to avoidkilling them, but they are not

// immediately visible. An example isbackground music playback.

static final int PERCEPTIBLE_APP_ADJ = 2;

// This is a process only hostingactivities that are visible to the

// user, so we'd prefer they don'tdisappear.

static final int VISIBLE_APP_ADJ = 1;

// This is the process running the currentforeground app. We'd really

// rather not kill it!

static final int FOREGROUND_APP_ADJ = 0;

// This is a systempersistent 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;

c) kernel/linux/linux-3.7.2/drivers/staging/android/lowmemorykiller.c

lowmem_shrink() –> 找到符合条件的process并将其kill掉

当cache memory size < = minfree * 4时，lmk会将minfree对应的oom_adj或大于此oom_adj的进程kill掉，具体规则见lowmem_shrink函数

Ps： cache memory size可以通过“cat /proc/meminfo”查看

static int lowmem_shrink(structshrinker *s, struct shrink_control *sc)

{

…

for_each_process(tsk){

struct task_struct *p;

int oom_score_adj;

if (tsk->flags & PF_KTHREAD)

continue;

p = find_lock_task_mm(tsk);

if (!p)

continue;

if (test_tsk_thread_flag(p,TIF_MEMDIE) &&

time_before_eq(jiffies, lowmem_deathpending_timeout)) {

task_unlock(p);

rcu_read_unlock();

lowmem_print(4, "lowmem_shrink %lu,%x, wait %s %d %d %d (%s %d)\n",

sc->nr_to_scan,sc->gfp_mask, p->comm, p->pid,jiffies, lowmem_deathpending_timeout,current->comm, current->pid);

return 0;

}

oom_score_adj =p->signal->oom_score_adj;

if (oom_score_adj <min_score_adj) {

task_unlock(p);

continue;

}

tasksize = get_mm_rss(p->mm);

task_unlock(p);

if (tasksize <= 0)

continue;

if (selected) {

if (oom_score_adj <selected_oom_score_adj)

continue;

if (oom_score_adj ==selected_oom_score_adj &&

tasksize <= selected_tasksize)

continue;

}

selected = p;

selected_tasksize = tasksize;

selected_oom_score_adj =oom_score_adj;

lowmem_print(2, "select %d(%s), adj %d, size %d, to kill (%s %d) %d\n",

p->pid, p->comm,oom_score_adj, tasksize, current->comm, current->pid, jiffies);

}

…

}

#define OOM_SCORE_ADJ_MAX 1000

#define OOM_DISABLE(-17)

static intlowmem_oom_adj_to_oom_score_adj(int oom_adj)

{

if (oom_adj == OOM_ADJUST_MAX)

returnOOM_SCORE_ADJ_MAX;

else

return (oom_adj *OOM_SCORE_ADJ_MAX) / -OOM_DISABLE;

}

d) 若发现apk自动退出且从log中看不出异常信息，可能是该apk进程被lmk干掉了

确认方法：

开启kernel log，并将kernel log priority 设为8，重启平台后复现

Kernellog：

<6>[ 729.920769] lowmemorykiller: Killing'way.tvlive2:cde' (1579), adj 58,

<6>[ 729.920769] to free 65628kB on behalf of 'kswapd0' (30) because

<6>[ 729.920769] cache 8156kB is below limit 8192kB for oom_score_adj 58

<6>[ 729.920769] Free memory is3992kB above reserved

9. 系统卡死

a) ANR （ApplicationNot Responding）

默认情况下，在android中Activity的最长执行时间是5秒，BroadcastReceiver的最长执行时间则是10秒。超出就会提示应用程序无响应（ANR：ApplicationNot Responding）对话框

anr时会在板子/data/anr目录下产生文档”traces.txt”，其中详细描述了卡住的位置

Ps：新产生的traces.txt会把旧的覆盖掉，所以出现问题时要尽早将traces.txt拉出来

b) CPU满负载

这种情况一般无traces.txt产生，且串口输入命令响应缓慢

i. top –t –m 5

User 0%, System 99%, IOW 0%, IRQ 0%

User 41 + Nice 1 + Sys 10831 + Idle0 + IOW 0 + IRQ 0 + SIRQ 58 = 10931

PID TID PR CPU%S VSS RSS PCYUID Thread Proc
3018 3058 0 61% R 444140K 50912K fgu0_a38 way.tvlive2:cde com.elinkway.tvlive2:cde

51 51 0 12% D 0K 0K fg root mmcqd/0

92 3255 0 1% S 73996K 9628K fg media NuPlayerDecoder /system/bin/mediaserver

31 31 0 1% S 0K 0K fg root ksmd

4 4 0 0% S 0K 0K fg root ksoftirqd/0

ii. vmstat

procs memory system cpu

r b free mapped anon slab in cs flt us ni sy id wa ir

2 24 29184 1400 171956 21588 719121188 1576 1 0 99 0 0 0

2 30 29476 1316 171872 21588 1068631240 2581 0 0 99 0 0 0

2 29 29804 1148 171932 21588 435213105 604 0 0 99 0 0 0

2 19 29672 1288 171848 21588 674720415 1657 0 0 99 0 0 0

2 25 29672 1312 171924 21588 396211264 668 2 0 99 0 0 0

cs 每秒上下文切换次数，例如我们调用系统函数，就要进行上下文切换，线程的切换，也要进程上下文切换，这个值要越小越好，太大了，要考虑调低线程或者进程的数目。每次调用系统函数，我们的代码就会进入内核空间，导致上下文切换，这个是很耗资源，也要尽量避免频繁调用系统函数。上下文切换次数过多表示你的CPU大部分浪费在上下文切换，导致CPU干正经事的时间少了，CPU没有充分利用，是不可取的

iii. systrace

c) 死锁

遥控无响应，无traces.txt产生，通过debuggerd –b 命令将怀疑进程的所有backtrace印出来，并逐个线程查询是否有线程间死锁问题

root@android:/ # ps - T

USER PID PPID VSIZE RSS WCHAN PC NAME

root 1950 1915 105632 5372 ffffffff b6635918 STvServer

root@android:/ # debuggerd -b 1950 >/data/TvServer_debuggerd.txt

stack工具可以自动做addr2line动作，目前只适用于TvServer：

python stack --kk-home=~/Disk2/2984_KKTV/kernel/android/KK--symbols-dir=TvServer TvServer_debuggerd.txt > TvServer_debuggerd_stack.txt

PS：

TvServer必须是not stripped版本才可以转译，确认方法如下：

[malone_ma@AE5 TvServer]$ file TvServer

TvServer: ELF 32-bit LSB shared object, ARM, version 1(SYSV), dynamically linked (uses shared libs), not stripped

10. Crash (/data/tombstones)

空指针调用/除0错误等会造成crash，而一般情况下apkcrash只会导致应用退出，大部分导致系统重启的是TvServer crash

出现crash时系统会在/data/tombstones文件夹下产生tombstone_xx文档

JB/kernel/android/KK/prebuilts/gcc/linux-x86/arm/arm-eabi-4.6/bin/arm-eabi-addr2line -C -f -e TvServer 000dd221

11. 快速替换video fw的方法

a) 将video_firmware.bin拷贝至u盘根目录

b) 按空格键AC上电

c) usb start

d) fatload usb 0:1 0x01a00000video_firmware.bin

e) go all

PS：重启后新video fw失效

作者: bean.yang 时间: 2016-7-22 09:05

作者: halleyhuang 时间: 2016-7-25 18:18
非常好的分享，收藏了

作者: HaoQiao 时间: 2016-8-8 17:52
感觉也很复杂的样子哦

作者: liugewill 时间: 2017-3-17 09:36
看起来比较复杂啊。

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