[20190401]隐含参数_mutex_spin_count.txt

电玩女神 2022-01-10 02:53 249阅读 0赞

\[20190401\]隐含参数\_mutex\_spin\_count.txt  
  
\--//上午做了一些测试关于semtimedop函数调用,发现自己上个星期在一些问题上理解错误.  
\--//相关链接:  
\--//http://blog.itpub.net/267265/viewspace-2640002/  
\--//http://blog.itpub.net/267265/viewspace-2639675/  
\--//我当时相当然认为:  
16:04:56.410785 semtimedop(309166080, 0x7fff83068fd0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010684>  
\--//\{0, 10000000\} 是 timespec. 前面单位是秒,后面单位是纳秒(毫微秒) 1秒=10^9纳秒, 10000000/10^9 = .01.  
\--//这样每次调用semtimedop需要0.010xXX秒.  
\--//我的理解相当于不断spin,检查这个资源是否可用.2秒后调用getrusage.  
\--//我一直以为0.010684秒中的0.000684秒是spin的时间,犯了一个严重错误,主要不熟悉os函数调用.  
  
1.环境:  
SCOTT@book> @ ver1  
PORT\_STRING                    VERSION        BANNER  
\------------------------------ -------------- --------------------------------------------------------------------------------  
x86\_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production  
  
$ cat m2.txt  
set verify off  
column a noprint new\_value v\_a;  
select mod ( &&3 ,3) a  from dual ;  
alter session set optimizer\_index\_caching= &v\_a;  
host sleep $(echo &&3/50| bc -l )  
insert into job\_times values ( sys\_context ('userenv', 'sid') ,dbms\_utility.get\_time ,'&&2') ;  
commit ;  
declare  
v\_id number;  
v\_d date;  
begin  
    for i in 1 .. &&1 loop  
        --select  1 into v\_id from dual ;  
        --select  sysdate into v\_d from dual ;  
        select deptno into v\_id from dept where deptno=10;  
    end loop;  
end ;  
/  
update job\_times set time\_ela = dbms\_utility.get\_time - time\_ela where sid=sys\_context ('userenv', 'sid') and method='&&2';  
commit;  
  
2.测试:  
$ seq 150 | xargs -I \{\}  -P 150 bash -c  "sqlplus -s -l scott/book @m2.txt 1e6 f2\_150 \{\} >/dev/null"  
  
SYS@book> @ mutexy 5 a31kd5tkdvvmm  
      HASH SUM\_SLEEPS   SUM\_GETS LOCATION                       MUTEX\_TYPE           MUTEX\_ADDR       SQLID         KGLNAOWN             C100  
\---------- ---------- ---------- ------------------------------ -------------------- ---------------- ------------- -------------------- ---------------------------------------  
1692266099     759340 1.5029E+10 kksLockDelete \[KKSCHLPIN6\]     Cursor Pin           000000007C3104F0 a31kd5tkdvvmm                      SELECT DEPTNO FROM DEPT WHERE DEPTNO=10  
1692266099     534864 1.0520E+10 kksfbc \[KKSCHLFSP2\]            Cursor Pin           000000007C3104F0 a31kd5tkdvvmm                      SELECT DEPTNO FROM DEPT WHERE DEPTNO=10  
1692266099         10   97864344 kksHeapReadUnlock \[KKSCHLRDUP\] Cursor Pin           000000007C3104F0 a31kd5tkdvvmm                      SELECT DEPTNO FROM DEPT WHERE DEPTNO=10  
\--//MUTEX\_ADDR=000000007C3104F0  
  
\--//session 1:  
SCOTT@book> @ spid  
       SID    SERIAL\# PROCESS                  SERVER    SPID       PID  P\_SERIAL\# C50  
\---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------  
        51          3 60173                    DEDICATED 60174       27        121 alter system kill session '51,3' immediate;  
\--//51=0x33,进程号=60174.  
  
\--//session 22  
SYS@book> oradebug setmypid  
Statement processed.  
  
SYS@book> oradebug peek 0x000000007C3104F0 8  
\[07C3104F0, 07C3104F8) = 00000000 00000000  
  
SYS@book> oradebug poke 0x000000007C3104F0 8 0x0000000100000033  
BEFORE: \[07C3104F0, 07C3104F8) = 00000000 00000000  
AFTER:  \[07C3104F0, 07C3104F8) = 00000033 00000001  
\--//人为设置阻塞,前面4位阻塞sid,后面表示ref count.  
\--//修改\_mutex\_spin\_count参数:  
  
SCOTT@book> @ m2.txt 1 c1 0  
1 row created.  
Commit complete.  
\--//挂起!!  
  
$ strace  -fTr -p 60258  
     Process 60258 attached - interrupt to quit  
     0.010452 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010918>  
     0.011051 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010854>  
     0.010987 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010806>  
     0.010939 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010908>  
     0.011039 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010828>  
     0.010959 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010909>  
     0.011041 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010872>  
     0.011015 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010814>  
     0.010945 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010904>  
     0.011037 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010873>  
     0.011008 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010821>  
     0.010953 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010900>  
     0.011032 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010886>  
     0.011018 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010824>  
     0.010955 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010939>  
     0.011072 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010867>  
     0.010998 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010821>  
     0.010957 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010873>  
     0.011005 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010865>  
     0.010997 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010868>  
     0.011023 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010850>  
     0.010983 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010839>  
     0.010971 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010897>  
     0.011034 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010858>  
     0.010992 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010836>  
     0.010970 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010896>  
     0.011029 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010870>  
     0.011004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010831>  
     0.010963 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010902>  
     0.011035 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010890>  
     0.011023 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010823>  
     0.010956 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010892>  
     0.011023 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010874>  
     0.011007 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010835>  
     0.010971 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010883>  
     0.011021 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010885>  
     0.011019 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010850>  
     0.010991 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010858>  
     0.010991 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010830>  
     0.010962 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010903>  
     0.011037 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010854>  
     0.010997 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010838>  
     0.010982 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010909>  
     0.011046 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010868>  
     0.011011 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010795>  
     0.010928 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010906>  
     0.011037 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010878>  
     0.011009 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010821>  
     0.010953 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010901>  
     0.011033 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010884>  
     0.011016 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010858>  
     0.010996 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010857>  
     0.010988 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010868>  
     0.011003 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010873>  
     0.011010 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010860>  
     0.010993 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010862>  
     0.010993 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010875>  
     0.011030 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010841>  
     0.010973 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010850>  
     0.010982 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010924>  
     0.011082 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010830>  
     0.010966 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010804>  
     0.010937 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010897>  
     0.011030 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010887>  
     0.011020 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010822>  
     0.010958 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010892>  
     0.011025 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010867>  
     0.010999 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010852>  
\--//过滤semtimedop,截取第1列,注意排除第1行最后1行.保存文件为/tmp/a1.txt.  
  
SYS@book> oradebug poke 0x000000007C3104F0 8 0x0  
BEFORE: \[07C3104F0, 07C3104F8) = 00000033 00000002  
AFTER:  \[07C3104F0, 07C3104F8) = 00000000 00000000  
  
$ awk '\{print $1\}' /tmp/a1.txt | sed 1d | sed '$d' |awk '\{j++;i=i+$NF\}END\{print i,i/j\}'  
0.726011 0.0110002  
\--//可以发现上一个函数semtimedop调用,与下一个调用.平均值是0.0110002秒.  
  
3.修改参数\_mutex\_spin\_count:  
  
SYS@book> alter system set "\_mutex\_spin\_count"=11165535 scope=memory;  
alter system set "\_mutex\_spin\_count"=11165535 scope=memory  
\*  
ERROR at line 1:  
ORA-00068: invalid value 11165535 for parameter \_mutex\_spin\_count, must be between 0 and 65535  
\--//\_mutex\_spin\_count 最大65535.  
  
SYS@book> alter system set "\_mutex\_spin\_count"=65535 scope=memory;  
System altered.  
  
\--//重复前面的步骤:  
  
$ strace  -fTr -p 60258  
...  
     0.010478 getrusage(RUSAGE\_SELF, \{ru\_utime=\{33, 230948\}, ru\_stime=\{0, 146977\}, ...\}) = 0 <0.000019>  
     0.000107 getrusage(RUSAGE\_SELF, \{ru\_utime=\{33, 230948\}, ru\_stime=\{0, 146977\}, ...\}) = 0 <0.000017>  
     0.001643 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010135>  
     0.011752 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010376>  
     0.011982 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010381>  
     0.011983 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010405>  
     0.012077 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010339>  
     0.011976 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010343>  
     0.011936 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010422>  
     0.012068 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010353>  
     0.011988 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010351>  
     0.011949 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010416>  
     0.012424 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.011000>  
     0.012631 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010349>  
     0.011949 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010414>  
     0.012045 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010371>  
     0.012010 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010342>  
     0.011940 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010415>  
     0.012240 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010196>  
     0.011838 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010328>  
     0.011983 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010372>  
     0.011996 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010375>  
     0.012006 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010320>  
     0.011954 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010390>  
     0.012018 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010401>  
     0.011983 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010390>  
     0.011992 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010408>  
     0.011957 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010451>  
     0.012061 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010391>  
     0.012019 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010382>  
     0.011960 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010383>  
     0.011980 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010442>  
     0.012022 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010413>  
     0.011993 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010478>  
     0.012058 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010383>  
     0.011934 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010397>  
     0.011974 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010456>  
     0.012037 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010431>  
     0.012049 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010334>  
     0.011914 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010454>  
     0.012035 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010425>  
     0.012031 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010389>  
     0.011995 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010396>  
     0.011975 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010385>  
     0.011990 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010427>  
     0.012004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010428>  
     0.012033 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010414>  
     0.012020 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010381>  
     0.011931 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010405>  
     0.012008 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010438>  
     0.012025 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010424>  
     0.012010 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010360>  
     0.011969 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010428>  
     0.011988 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010408>  
     0.011986 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010458>  
     0.012066 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010396>  
     0.012011 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010343>  
     0.011902 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010480>  
     0.012029 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010456>  
     0.012071 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010338>  
     0.011949 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010449>  
     0.012000 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010451>  
     0.012058 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010375>  
     0.011981 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010392>  
     0.012395 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.011006>  
     0.012610 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010377>  
     0.011955 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010402>  
     0.012004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010420>  
     0.012008 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010426>  
     0.012004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010373>  
     0.011976 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010438>  
     0.012046 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010402>  
     0.012009 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010342>  
     0.011920 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010462>  
     0.012011 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010419>  
     0.011998 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010457>  
     0.012071 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010397>  
     0.012006 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010379>  
     0.011973 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010405>  
     0.011981 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010399>  
     0.012004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010418>  
     0.011992 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010431>  
     0.011991 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010400>  
     0.012003 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010436>  
     0.012044 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010356>  
     0.011962 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010430>  
     0.012032 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010407>  
     0.011960 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010397>  
     0.011998 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010436>  
     0.012017 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010435>  
     0.012063 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010318>  
     0.011924 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010437>  
     0.011986 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010448>  
     0.012026 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010434>  
     0.012015 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010405>  
     0.011982 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010413>  
     0.011992 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010428>  
     0.012005 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010428>  
     0.012004 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010427>  
     0.012055 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010364>  
     0.011915 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010417>  
     0.012020 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010441>  
     0.012039 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010390>  
     0.011991 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010386>  
     0.011963 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010438>  
     0.012019 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010383>  
     0.011988 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010434>  
     0.012018 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010426>  
     0.012053 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010323>  
     0.011907 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010455>  
     0.012031 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010423>  
     0.012001 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010446>  
     0.012050 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}) = -1 EAGAIN (Resource temporarily unavailable) <0.010384>  
     0.011963 semtimedop(309821440, 0x7fffe52f56a0, 1, \{0, 10000000\}^C <unfinished ...>  
\--//过滤semtimedop,截取第1列,注意排除第1行最后1行.保存文件为/tmp/a1.txt.  
      
$ awk '\{print $1\}' /tmp/a2.txt | sed 1d | sed '$d' |awk '\{j++;i=i+$NF\}END\{print i,i/j\}'  
1.30971 0.0120157  
  
\--//可以发现上一个函数semtimedop调用,与下一个调用.平均值是0.0120157秒.  
\--//存在0.012-0.011 = 0.001差距. 虽然很小还是看出差距.  
\--//肉眼也可以发现后面的时间间隔基本是0.012xxx或者0.0119xxx.  
  
\--//再次测试:  
$ strace  -fTr -p 60258 -o /tmp/c1.txt  
  
$ awk '\{print $3\}' /tmp/c1.txt  | uniq -c |egrep "semtimedop|getrusag"  
    119 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    167 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    167 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    167 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    167 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
    166 semtimedop(309821440,  
      2 getrusage(RUSAGE\_SELF,  
...  
\--//semtimedop 167或者166次, getrusage 2次.也就是2秒时间内比原来调用semtimedop的次数少几次,原来是182次.  
\--//参考链接:http://blog.itpub.net/267265/viewspace-2639675/  
  
4.继续修改参数\_mutex\_spin\_count:  
  
SYS@book> alter system set "\_mutex\_spin\_count"=0 scope=memory;  
System altered.  
  
\--//基本看不出来.  
  
\--//补充cpu使用情况, "\_mutex\_spin\_count"=65535.  
\# top -p 60258  
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND  
60258 oracle    20   0  877m  40m  37m R 12.0  0.0   1:52.99 oracle  
  
\--//"\_mutex\_spin\_count"=65535.  
\# top -p 60258  
  PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND  
60258 oracle    20   0  877m  40m  37m S  0.3  0.0   1:58.61 oracle  
  
\--//从cpu的消耗也可以看出spin数量增加的情况下cpu消耗增加.  
  
5.总结:  
总之,时间间隔很小,但是还是能看出变化.  
不过cpu的使用率还是可以看出明显的变化.

转载于:https://www.cnblogs.com/lfree/p/10637212.html