digoal
2013-10-17
PostgreSQL , Linux , systemtap , stap , dtrace , probe
Tapset这本手册很全, 罗列了大量的函数, 探针别名, 本文抽取一些常用到的函数, 方便查找 :
function::asmlinkage — Mark function as declared asmlinkage
asmlinkage()函数在kprobe探针中常用, 在取函数变量前调用, 参考
http://blog.163.com/digoal@126/blog/static/163877040201382914152385/
function::cmdline_arg — Fetch a command line argument
function::cmdline_args — Fetch command line arguments from current process
取命令行参数, 或命令本身, 返回字符串.
function::cmdline_str — Fetch all command line arguments from current process
取命令行以及所有参数.
如
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e '
probe syscall.read {
if (execname() =="postgres") println(cmdline_arg(0))
}'
postgres: wal writer process
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e '
probe syscall.read {
if (execname() =="postgres") println(cmdline_str())
}'
postgres: wal writer process "" "" ""
function::cpu — Returns the current cpu number
多核CPU的情况下, 可用以区分哪个核.
function::execname — Returns the execname of a target process (or group of processes)
取进程名, 或一组进程的进程名, 例如postgresql fork出来的进程execname()都等于"postgres"
function::egid — Returns the effective gid of a target process
function::euid — Return the effective uid of a target process
function::gid — Returns the group ID of a target process
function::uid — Returns the user ID of a target process
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e '
probe syscall.read {
if (execname() =="postgres") printdln("**",euid(),egid())
}'
500**500
[root@db-172-16-3-150 postgresql-9.3.1]id pg93
uid=500(pg93) gid=500(pg93) groups=500(pg93)
function::int_arg — Return function argument as signed int
function::long_arg — Return function argument as signed long
function::longlong_arg — Return function argument as 64-bit value
function::pointer_arg — Return function argument as pointer value
function::s32_arg — Return function argument as signed 32-bit value
function::s64_arg — Return function argument as signed 64-bit value
function::u32_arg — Return function argument as unsigned 32-bit value
function::u64_arg — Return function argument as unsigned 64-bit value
function::uint_arg — Return function argument as unsigned int
function::ulong_arg — Return function argument as unsigned long
function::ulonglong_arg — Return function argument as 64-bit value
kprobe中用来获取探针函数的变量值, 不同的类型使用不同的*_arg函数来获取.
参考:
http://blog.163.com/digoal@126/blog/static/163877040201382914152385/
function::is_return — Whether the current probe context is a return probe
判断是否为return probe. 例如
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e 'probe syscall.read.return { if (is_return()) {println(pn(), " is a return call."); exit()} else println(pn(), " is not a return call."); exit()}'
syscall.read.return is a return call.
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e 'probe syscall.read { if (is_return()) {println(pn(), " is a return call."); exit()} else println(pn(), " is not a return call."); exit()}'
syscall.read is not a return call.
function::pexecname — Returns the execname of a target process's parent process
function::pgrp — Returns the process group ID of the current process
function::ppid — Returns the process ID of a target process's parent process
function::pid — Returns the ID of a target process
function::uid — Returns the user ID of a target process
function::tid — Returns the thread ID of a target process
function::pid2execname — The name of the given process identifier
function::pid2task — The task_struct of the given process identifier
用以得到进程的pid, gid, tid, uid; 父进程的execname, pid; 从指定进程号得到execname();
function::pn — Returns the active probe name
function::pp — Returns the active probe point
function::ppfunc — Returns the function name parsed from pp
function::stp_pid — The process id of the stapio process
得到探针名, 探针, 从探针中解析到的函数名, 以及stap运行时的stapio进程的pid.
function::target — Return the process ID of the target process
在stap target process模式(stap -x or -c)中得到target process的pid.
function::cpu_clock_ms — Number of milliseconds on the given cpu's clock
function::cpu_clock_ns — Number of nanoseconds on the given cpu's clock
function::cpu_clock_s — Number of seconds on the given cpu's clock
function::cpu_clock_us — Number of microseconds on the given cpu's clock
获取指定cpu的时间
例如
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e 'probe begin {printdln("*",cpu_clock_ms(0),cpu_clock_ms(1),cpu_clock_ms(2),cpu_clock_ms(3),cpu_clock_ms(4),cpu_clock_ms(5),cpu_clock_ms(6),cpu_clock_ms(7)); exit()}'
369796642*369796642*369796642*369796642*369796642*369796642*369796642*369796642
function::gettimeofday_ms — Number of milliseconds since UNIX epoch
function::gettimeofday_ns — Number of nanoseconds since UNIX epoch
function::gettimeofday_s — Number of seconds since UNIX epoch
function::gettimeofday_us — Number of microseconds since UNIX epoch
获取UNIX epoch相对时间
function::local_clock_ms — Number of milliseconds on the local cpu's clock
function::local_clock_ns — Number of nanoseconds on the local cpu's clock
function::local_clock_s — Number of seconds on the local cpu's clock
function::local_clock_us — Number of microseconds on the local cpu's clock
获取本地CPU的时间,
[root@db-172-16-3-150 postgresql-9.3.1]# stap -e 'probe begin {printdln("*", gettimeofday_ns(), local_clock_ns()); exit()}'
1381991942316960497*370059058163884
重启后本地时间归0
[root@db-172-16-3-150 ~]# stap -e 'probe begin {printdln("*", gettimeofday_ns(), local_clock_s()); exit()}'
1381992447423506944*160
[root@db-172-16-3-150 ~]# w
14:47:30 up 2 min, 1 user, load average: 0.20, 0.05, 0.01
USER TTY FROM LOGIN@ IDLE JCPU PCPU WHAT
root pts/0 172.16.8.31 14:47 0.00s 0.02s 0.00s w
function::ctime — Convert seconds since epoch into human readable date/time string
function::tz_ctime — Convert seconds since epoch into human readable date/time string, with local time zone
function::tz_gmtoff — Return local time zone offset
function::tz_name — Return local time zone name
转换成可读时间
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(ctime(gettimeofday_s())); exit()}'
Thu Oct 17 06:48:35 2013
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(tz_ctime(gettimeofday_s())); exit()}'
Thu Oct 17 14:49:35 2013 CST
function::system — Issue a command to the system
在stap脚本中执行外部命令
[root@db-172-16-3-150 ~]# stap -e 'probe begin {system("echo -e \"hello\" > ./t"); exit()}'
[root@db-172-16-3-150 ~]# cat t
hello
function::bytes_to_string — Human readable string for given bytes
输入数字, 单位为byte, 转换成可读的存储容量字符串.
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(bytes_to_string(12)); exit()}'
12
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(bytes_to_string(120)); exit()}'
120
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(bytes_to_string(1200000000000000000)); exit()}'
1117587089G
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(bytes_to_string(120000000)); exit()}'
114M
function::mem_page_size — Number of bytes in a page for this architecture
返回内存一页大小字节.
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(mem_page_size()); exit()}'
4096
function::pages_to_string — Turns pages into a human readable string
输入数字, 单位为page, 转换成可读的存储容量字符串.
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(pages_to_string(120000000)); exit()}'
457G
function::proc_mem_data — Program data size (data + stack) in pages
function::proc_mem_data_pid — Program data size (data + stack) in pages
function::proc_mem_rss — Program resident set size in pages
function::proc_mem_rss_pid — Program resident set size in pages
function::proc_mem_shr — Program shared pages (from shared mappings)
function::proc_mem_shr_pid — Program shared pages (from shared mappings)
function::proc_mem_size — Total program virtual memory size in pages
function::proc_mem_size_pid — Total program virtual memory size in pages
function::proc_mem_string — Human readable string of current proc memory usage
function::proc_mem_string_pid — Human readable string of process memory usage
function::proc_mem_txt — Program text (code) size in pages
function::proc_mem_txt_pid — Program text (code) size in pages
获取程序内存中各个区块的空间大小. 单位内存页.
[root@db-172-16-3-150 ~]# ps -ewf|grep postgres
pg93 5345 1 0 14:58 pts/0 00:00:00 /home/pg93/pgsql9.3.1/bin/postgres
# - Memory -
shared_buffers = 2048MB # min 128kB
# (change requires restart)
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(proc_mem_shr_pid(5345)); exit()}'
17785
function::cputime_to_msecs — Translates the given cputime into milliseconds
function::cputime_to_string — Human readable string for given cputime
function::msecs_to_string — Human readable string for given milliseconds
function::task_stime — System time of the current task
function::task_stime_tid — System time of the given task
function::task_time_string — Human readable string of task time usage
function::task_time_string_tid — Human readable string of task time usage
function::task_utime — User time of the current task
function::task_utime_tid — User time of the given task
任务消耗的CPUtime, 区分user time, sys time.
[root@db-172-16-3-150 ~]# ps -ewf|grep pg93
pg93 5345 1 0 14:58 pts/0 00:00:00 /home/pg93/pgsql9.3.1/bin/postgres
[root@db-172-16-3-150 ~]# stap -e 'probe begin {println(task_time_string_tid(5345)); exit()}'
usr: 0m0.028s, sys: 0m0.059s
1. https://sourceware.org/systemtap/tapsets/
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