top命令

usage: top [-Hbq] [-k FIELD,] [-o FIELD,] [-s SORT] [-n NUMBER] [-m LINES] [-d SECONDS] [-p PID,] [-u USER,]

Show process activity in real time.

-H	Show threads
-k	Fallback sort FIELDS (default -S,-%CPU,-ETIME,-PID)
-o	Show FIELDS (def PID,USER,PR,NI,VIRT,RES,SHR,S,%CPU,%MEM,TIME+,CMDLINE)
-O	Add FIELDS (replacing PR,NI,VIRT,RES,SHR,S from default)
-s	Sort by field number (1-X, default 9)
-b	Batch mode (no tty)
-d	Delay SECONDS between each cycle (default 3)
-m	Maximum number of tasks to show
-n	Exit after NUMBER iterations
-p	Show these PIDs
-u	Show these USERs
-q	Quiet (no header lines)

Cursor LEFT/RIGHT to change sort, UP/DOWN move list, space to force
update, R to reverse sort, Q to exit.

VIRT：virtual memory usage 虚拟内存
1、进程“需要的”虚拟内存大小，包括进程使用的库、代码、数据等
2、假如进程申请100m的内存，但实际只使用了10m，那么它会增长100m，而不是实际的使用量

RES：resident memory usage 常驻内存
1、进程当前使用的内存大小，但不包括swap out
2、包含其他进程的共享
3、如果申请100m的内存，实际使用10m，它只增长10m，与VIRT相反
4、关于库占用内存的情况，它只统计加载的库文件所占内存大小

SHR：shared memory 共享内存
1、除了自身进程的共享内存，也包括其他进程的共享内存
2、虽然进程只使用了几个共享库的函数，但它包含了整个共享库的大小
3、计算某个进程所占的物理内存大小公式：RES – SHR
4、swap out后，它将会降下来

ps命令

[C:\~]$ adb shell ps --help
usage: ps [-AadefLlnwZ] [-gG GROUP,] [-k FIELD,] [-o FIELD,] [-p PID,] [-t TTY,] [-uU USER,]

List processes.

Which processes to show (selections may be comma separated lists):

-A	All processes
-a	Processes with terminals that aren't session leaders
-d	All processes that aren't session leaders
-e	Same as -A
-g	Belonging to GROUPs
-G	Belonging to real GROUPs (before sgid)
-p	PIDs (--pid)
-P	Parent PIDs (--ppid)
-s	In session IDs
-t	Attached to selected TTYs
-T	Show threads
-u	Owned by USERs
-U	Owned by real USERs (before suid)

Output modifiers:

-k	Sort FIELDs in +increasing or -decreasting order (--sort)
-M	Measure field widths (expanding as necessary)
-n	Show numeric USER and GROUP
-w	Wide output (don't truncate fields)

Which FIELDs to show. (Default = -o PID,TTY,TIME,CMD)

-f	Full listing (-o USER:12=UID,PID,PPID,C,STIME,TTY,TIME,ARGS=CMD)
-l	Long listing (-o F,S,UID,PID,PPID,C,PRI,NI,ADDR,SZ,WCHAN,TTY,TIME,CMD)
-o	Output FIELDs instead of defaults, each with optional :size and =title
-O	Add FIELDS to defaults
-Z	Include LABEL

Command line -o fields:

  ARGS     CMDLINE minus initial path     CMD  Command (thread) name (stat[2])
  CMDLINE  Command line (argv[])          COMM Command filename (/proc/$PID/exe)
  COMMAND  Command file (/proc/$PID/exe)  NAME Process name (argv[0] of $PID)

Process attribute -o FIELDs:

  ADDR  Instruction pointer               BIT   Is this process 32 or 64 bits
  CPU   Which processor running on        ETIME   Elapsed time since PID start
  F     Flags (1=FORKNOEXEC 4=SUPERPRIV)  GID     Group id
  GROUP Group name                        LABEL   Security label
  MAJFL Major page faults                 MINFL   Minor page faults
  NI    Niceness (lower is faster)
  PCPU  Percentage of CPU time used       PCY     Android scheduling policy
  PGID  Process Group ID
  PID   Process ID                        PPID    Parent Process ID
  PRI   Priority (higher is faster)       PSR     Processor last executed on
  RGID  Real (before sgid) group ID       RGROUP  Real (before sgid) group name
  RSS   Resident Set Size (pages in use)  RTPRIO  Realtime priority
  RUID  Real (before suid) user ID        RUSER   Real (before suid) user name
  S     Process state:
        R (running) S (sleeping) D (device I/O) T (stopped)  t (traced)
        Z (zombie)  X (deader)   x (dead)       K (wakekill) W (waking)
  SCHED Scheduling policy (0=other, 1=fifo, 2=rr, 3=batch, 4=iso, 5=idle)
  STAT  Process state (S) plus:
        < high priority          N low priority L locked memory
        s session leader         + foreground   l multithreaded
  STIME Start time of process in hh:mm (size :19 shows yyyy-mm-dd hh:mm:ss)
  SZ    Memory Size (4k pages needed to completely swap out process)
  TCNT  Thread count                      TID     Thread ID
  TIME  CPU time consumed                 TTY     Controlling terminal
  UID   User id                           USER    User name
  VSZ   Virtual memory size (1k units)    %VSZ    VSZ as % of physical memory
  WCHAN What are we waiting in kernel for

UID：用户ID，实际输出的是用户名，如root

PID：当前进程的ID

PPID：当前进程的父进程ID

C：当前进程占用的CPU的百分比

STIME：当前进程启动到现在的时间

TTY：当前进程在哪个终端上运行，若与进程无关，则显示为？，若为pts/0等，则表示由网络连接主机进程。

CMD：命令的名称和参数

进程stat状态
    无法中断的休眠状态（通常 IO 的进程）；
    R 正在运行可中在队列中可过行的;
    S 处于休眠状态；
    T 停止或被追踪；
    W 进入内存交换;
    X 死掉的进程;
    Z 僵尸进程;
    优先级高的进程
    N 优先级较低的进程
    L 有些页被锁进内存
    s 进程的领导者（在它之下有子进程）
    l 多进程的（使用 CLONE_THREAD, 类似 NPTL pthreads）;
    + 位于后台的进程组；