|
sp; 16
LADDR
----------------
0000000060009A18
Statement processed.
--//回到window 3,按ctrl+c中断:
(gdb) c
Continuing.
^C
Program received signal SIGINT, Interrupt.
0x00000037990d6407 in semop () from /lib64/libc.so.6
(gdb) bt 8
#0 0x00000037990d6407 in semop () from /lib64/libc.so.6
#1 0x0000000009809c0f in sskgpwwait ()
#2 0x00000000098089ce in skgpwwait ()
#3 0x0000000000a86d3f in kslgess ()
#4 0x00000000093faca5 in ksl_get_shared_latch ()
#5 0x0000000004a2c53e in kslgetsl_w ()
#6 0x0000000007d74142 in skdxcall ()
#7 0x00000000076c96aa in ksdxcall ()
(More stack frames follow...)
--//可以确定函数调用的堆栈或者称为顺序,当前停在semop睡眠上,可以发现调用kslgetsl_w后,ksl_get_shared_latch,
--//紧接着的是kslgess.这样猜测spin计数在调用kslgess或者ksl_get_shared_latch函数里面.
2.重复前面测试,在gdb下设置断点:
--//在session 1按ctrl+c,退出window 3的gdb程序,重新执行gdb.
--//window 3:
$ rlwrap gdb -p 30319
(gdb) break kslgess
Breakpoint 1 at 0xa865ca
--//设置断点在kslgess函数调用上.然后在session 1,2分别执行(后面不再说明):
--//再次挂起!在window 3,执行如下:
--//如果我执行ni 1000应该不会错过什么,可以这时看寄存器应该猜测spin count在那个寄存器中.
--//跟踪半天不对,看了链接https://fritshoogland.wordpress.com/2015/07/17/oracle-12-and-latches-part-2/
--//应该在kslskgs函数中.
(gdb) break kslskgs
Breakpoint 1 at 0xa874fa
(gdb) c
Continuing.
Breakpoint 1, 0x0000000000a874fa in kslskgs ()
(gdb) ni 100
..
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875e3 0xa875e3 <kslskgs+237>
(gdb) ni
0x0000000000a875be in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875be 0xa875be <kslskgs+200>
(gdb) ni
0x0000000000a875c8 in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875c8 0xa875c8 <kslskgs+210>
(gdb) ni
0x0000000000a875cb in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875cb 0xa875cb <kslskgs+213>
(gdb) ni
0x0000000000a875d1 in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875d1 0xa875d1 <kslskgs+219>
(gdb) ni
0x0000000000a875d4 in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875d4 0xa875d4 <kslskgs+222>
(gdb) ni
0x0000000000a875da in kslskgs ()
(gdb) info regi r13 rip
r13 0x764 1892
rip 0xa875da 0xa875da <kslskgs+228>
(gdb) ni
0x0000000000a875dd in kslskgs ()
(gdb) info regi r13 rip
r13 |