[20190401]隐含参数_mutex_spin_count.txt

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[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.