[20190402]对比_mutex_wait_scheme不同模式cpu消耗.txt
[20190402]对比_mutex_wait_scheme不同模式cpu消耗.txt
--//前几天做了sql语句在mutexes上的探究.今天对比不同_mutex_wait_scheme模式cpu消耗.
1.环境:
SYS@book> @ hide mutex
NAME DESCRIPTION DEFAULT_VALUE SESSION_VALUE SYSTEM_VALUE
------------------- ------------------ ------------- ------------- ------------
_mutex_spin_count Mutex spin count TRUE 255 255
_mutex_wait_scheme Mutex wait scheme TRUE 2 2
_mutex_wait_time Mutex wait time TRUE 1 1
--//注:_mutex_wait_time=1,相当1厘秒.
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_cost_adj= &&3;
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;
--quit
$ seq 150 | xargs -I {} -P 150 bash -c "sqlplus -s -l scott/book @m2.txt 1e6 f2_150 {} >/dev/null"
SYS@book> @ mutexy 6 a31kd5tkdvvmm
HASH SUM_SLEEPS SUM_GETS LOCATION MUTEX_TYPE MUTEX_ADDR SQLID KGLNAOWN C100
---------- ---------- ---------- ------------------------------ -------------------- ---------------- ------------- -------- ---------------------------------------
1692266099 2263154 4.6431E+10 kksLockDelete [KKSCHLPIN6] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 2183544 4.4733E+10 kksfbc [KKSCHLFSP2] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 5256 600010918 kksfbc [KKSCHLPIN1] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 6 45955498 kksHeapReadUnlock [KKSCHLRDUP] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
--//MUTEX_ADDR=000000007C88E330.
2.测试一:
--//测试_mutex_wait_scheme=2的情况:
--//session 1:
SCOTT@book> @ spid
SID SERIAL# PROCESS SERVER SPID PID P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
295 5 65222 DEDICATED 65223 21 3 alter system kill session '295,5' immediate;
--//session 2:
SYS@book> oradebug setmypid
Statement processed.
SYS@book> oradebug peek 0x000000007C88E330 8
[07C88E330, 07C88E338) = 00000000 00000000
SYS@book> oradebug poke 0x000000007C88E330 8 0x0000000200000127
BEFORE: [07C88E330, 07C88E338) = 00000000 00000000
AFTER: [07C88E330, 07C88E338) = 00000127 00000002
--//session 1:
SCOTT@book> @ m2.txt 1 c1 0
1 row created.
Commit complete.
--//挂起!!
$ top -p 65223
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
65223 oracle 20 0 857m 29m 25m S 0.3 0.0 0:00.41 oracle
--//CPU消耗0.3.
--//另外我执行如下:
SYS@book> @ mutexy 5 a31kd5tkdvvmm
HASH SUM_SLEEPS SUM_GETS LOCATION MUTEX_TYPE MUTEX_ADDR SQLID KGLNAOWN C100
---------- ---------- ---------- ------------------------------ -------------------- ---------------- ------------- -------- ---------------------------------------
1692266099 2263154 4.6431E+10 kksLockDelete [KKSCHLPIN6] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 2183544 4.4733E+10 kksfbc [KKSCHLFSP2] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 19266 600013714 kksfbc [KKSCHLPIN1] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 6 45955498 kksHeapReadUnlock [KKSCHLRDUP] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
--//等一会...
SYS@book> @ mutexy 5 a31kd5tkdvvmm
HASH SUM_SLEEPS SUM_GETS LOCATION MUTEX_TYPE MUTEX_ADDR SQLID KGLNAOWN C100
---------- ---------- ---------- ------------------------------ -------------------- ---------------- ------------- -------- ---------------------------------------
1692266099 2263154 4.6431E+10 kksLockDelete [KKSCHLPIN6] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 2183544 4.4733E+10 kksfbc [KKSCHLFSP2] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 26386 600013714 kksfbc [KKSCHLPIN1] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
1692266099 6 45955498 kksHeapReadUnlock [KKSCHLRDUP] Cursor Pin 000000007C88E330 a31kd5tkdvvmm SELECT DEPTNO FROM DEPT WHERE DEPTNO=10
--//仅仅LOCATION=kksfbc [KKSCHLPIN1],SUM_SLEEPS数量在增加.
AFTER: [07C88E330, 07C88E338) = 00000127 00000002
SYS@book> oradebug poke 0x000000007C88E330 8 0x0
BEFORE: [07C88E330, 07C88E338) = 00000127 00000002
AFTER: [07C88E330, 07C88E338) = 00000000 00000000
3.测试二:
--//测试_mutex_wait_scheme=1的情况:
--//基本重复上面的步骤,不再列出执行步骤.
SYS@book> alter system set "_mutex_wait_scheme"=1 scope=memory;
System altered.
$ top -p 65223
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
65223 oracle 20 0 857m 29m 25m S 3.0 0.0 0:01.29 oracle
--//CPU消耗3.
4.测试三:
--//测试_mutex_wait_scheme=1的情况:
--//基本重复上面的步骤,不再列出执行步骤.
SYS@book> alter system set "_mutex_wait_scheme"=0 scope=memory;
System altered.
$ top -p 65223
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
65223 oracle 20 0 857m 29m 25m S 39.9 0.0 0:06.99 oracle
--//CPU消耗39.9
5.总结:
--//画一个表格如下:
-------------------------------------------------------------------------------------------------------
_mutex_wait_scheme CPU使用率 描述
------------------------------------------------------------------------------------------------------
2 .3 2秒时间内,semtimedop 182次 getrusage 2次 _mutex_spin_count=255
12 2秒时间内,semtimedop 167次 getrusage 2次 _mutex_spin_count=65535
1 3 2秒时间内, select 16XX次(每次调用0.001秒).,getrusage 2次
0 39.9 调用99次sched_yield,然后1次seelct(每次调用0.001秒).
------------------------------------------------------------------------------------------------------
--//注:这是我当前硬件条件下的测试结果,而且我一直阻塞sql语句执行并且_mutex_wait_time=1的情况.
--//一些测试数据参考链接:
http://blog.itpub.net/267265/viewspace-2639675/
http://blog.itpub.net/267265/viewspace-2640003/
