[20181130]control file sequential read.txt

--//昨天上午探究了大量控制文件读的情况,链接:http://blog.itpub.net/267265/viewspace-2222146/
--//今天做一些细节探究:

1.环境:
SYS@xxxxx1> @ 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

--//建立执行脚本如下:
$ cat c.txt
select 'flashpct;'||trim(ceil(percent_space_used)) from V$FLASH_RECOVERY_AREA_USAGE where file_type='FLASHBACK LOG'
union all
select 'flashtime;'||to_char(OLDEST_FLASHBACK_TIME,'yyyy-mm-dd hh24:mi:ss') from V$FLASHBACK_DATABASE_LOG;

--//session 1:
SYS@xxxxx1> @ spid
       SID    SERIAL# PROCESS                  SERVER    SPID       PID  P_SERIAL# C50
---------- ---------- ------------------------ --------- ------ ------- ---------- --------------------------------------------------
        60      26633 1442                     DEDICATED 1443       418        203 alter system kill session '60,26633' immediate;
--//记下spid=1443.

2.使用strace跟踪
--//session 2:
$ strace -p 1443 -t -e pread  -o /tmp/aa1

--//切换到session 1:
SYS@xxxxx1> @ c.txt
'FLASHPCT;'||TRIM(CEIL(PERCENT_SPACE_USED))
-------------------------------------------------
flashpct;0

--//session 2,按ctrl+c退出:
# strace -p 1443 -t -e pread  -o /tmp/aa1
Process 1443 attached - interrupt to quit
^CProcess 1443 detached

# cat /tmp/aa1
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0J\3\0\0\1\255\3338\377\377\1\4B\27\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 476741632) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0r\0\0\0\306\333\2638\377\377\1\4{Z\0\0\3\0\2\0\0\0\0\0\0\0+D"..., 16384, 475168768) = 16384
16:10:10 pread(256, "\25\302\0\0s\0\0\0\377\254\3338\377\377\1\4u\31\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 475185152) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0i\4\0\0P<\3338\377\377\1\4(\324\0\0=\2\0\0\30\1\0\0v\0301;"..., 16384, 480395264) = 16384
16:10:10 pread(258, "\25\302\0\0|\4\0\0\200\212\3338\377\377\1\4\25q\0\0L\2\0\0000\2\0\0Z(2;"..., 16384, 480444416) = 16384
16:10:10 pread(257, "\25\302\0\0\232\4\0\0<r\3338\377\377\1\4\345\354\0\0`\2\0\0`\4\0\0\301]3;"..., 16384, 478445568) = 16384
16:10:10 pread(257, "\25\302\0\0\301\4\0\0!{\3338\377\377\1\4\3\247\0\0\216\2\0\0\301\10\0\0r\3015;"..., 16384, 477511680) = 16384
16:10:10 pread(257, "\25\302\0\0\35\5\0\0005\254\3218\377\377\1\4\376\274\0\0\350\2\0\0\177\21\0\0\36\7\24;"..., 16384, 478756864) = 16384
16:10:10 pread(258, "\25\302\0\0\323\1\0\00040\3338\377\377\1\4\261\306\0\0R\3650;\n\5\1\0\342\225\0\0"..., 16384, 473874432) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(257, "\25\302\0\0T\2\0\0qD\2407\377\377\1\4\251a\0\0u\332\2047\0\0\0\0\0\0\0\0"..., 16384, 475201536) = 16384
16:10:10 pread(257, "\25\302\0\0U\2\0\0\262\342\2638\377\377\1\4U\226\0\0bracontrolfi"..., 16384, 475217920) = 16384
16:10:10 pread(258, "\25\302\0\0X\2\0\0 \201\2708\377\377\1\4\t:\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 16384, 476184576) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(256, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 472924160) = 16384
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(258, "\25\302\0\0)\0\0\0J\261\3338\377\377\1\4\365\343\0\0\0\0\0\0\0\0\0\0k\237\2047"..., 16384, 473972736) = 16384
16:10:10 pread(258, "\25\302\0\0000\3\0\0B\261\3338\377\377\1\4[\r\0\0\30\0\f\0\340\7\0\0\0\0\0\0"..., 16384, 477626368) = 16384

# rev /tmp/aa1 | cut -f1 -d'=' | rev | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
950272

--//可以读的文件句柄是256,257,258.
# ls -l /proc/1443/fd | grep 25[678]
lrwx------ 1 root root 64 2018-11-29 16:10:11 256 -> /dev/asm-diskf
lrwx------ 1 root root 64 2018-11-29 16:10:11 257 -> /dev/asm-diskg
lrwx------ 1 root root 64 2018-11-29 16:10:11 258 -> /dev/asm-diske
--//可以发现对应以上裸设备.

--//单独看两个：
16:10:10 pread(257, "\25\302\0\0'\0\0\0J\261\3338\377\377\1\4}O\0\0\0\0P\0\0\0\200\0\0\0\0\0"..., 16384, 473022464) = 16384
16:10:10 pread(257, "\25\302\0\0\1\0\0\0\0\0\0\0\0\0\1\4\355\376\0\0\0\0\0\0\0\4 \v+^\3665"..., 16384, 480264192) = 16384

$ man pread
PREAD(2)  Linux Programmer's Manual                                PREAD(2)

NAME
       pread, pwrite - read from or write to a file descriptor at a given offset

SYNOPSIS
       #define _XOPEN_SOURCE 500
       #include
       ssize_t pread(int fd, void *buf, size_t count, off_t offset);
       ssize_t pwrite(int fd, const void *buf, size_t count, off_t offset);
--//第1个是句柄，第2个参数缓存地址指针，第3个是读取长度，第4个是偏移量。

473022464/1024/1024 = 451.10937500000000000000
480264192/1024/1024 = 458.01562500000000000000

--//以grid用户登录,访问asm实例:
SQL> column path format a40
SQL> select DISK_NUMBER,GROUP_NUMBER,PATH from v$asm_disk where GROUP_NUMBER=1 and DISK_NUMBER in(1,0,2) order by 1;
DISK_NUMBER GROUP_NUMBER PATH
----------- ------------ ----------------------------------------
          0            1 /dev/asm-diske
          1            1 /dev/asm-diskf
          2            1 /dev/asm-diskg

SQL> SELECT disk_kffxp, au_kffxp, xnum_kffxp,GROUP_KFFXP,NUMBER_KFFXP  FROM x$kffxp  WHERE (au_kffxp=451 or  au_kffxp=458) and disk_kffxp=2;
DISK_KFFXP   AU_KFFXP XNUM_KFFXP GROUP_KFFXP NUMBER_KFFXP
---------- ---------- ---------- ----------- ------------
         2        458          0           1          260
         2        451          4           1          261

--//NUMBER_KFFXP对应的是260,261.
--//使用asmcmd查看:

$ rlwrap asmcmd -p
ASMCMD [+] > ls -l data/xxxxx/controlfile
Type         Redund  Striped  Time                  Sys  Name
CONTROLFILE  UNPROT  FINE     2018/08/20 01:00:00                Y    Current.260.931438443
CONTROLFILE  UNPROT  FINE     2018/08/20 01:00:00                Y    Current.261.931438443

--//如下查询:

SQL> column type format a12
SQL> select * from v$asm_file where TYPE='CONTROLFILE' order by type;
GROUP_NUMBER FILE_NUMBER COMPOUND_INDEX INCARNATION BLOCK_SIZE     BLOCKS      BYTES      SPACE TYPE         REDUND STRIPE CREATION_ MODIFICAT R PERMISSIONS      USER_NUMBER USER_INCARNATION USERGROUP_NUMBER USERGROUP_INCARNATION PRIM MIRR  HOT_READS HOT_WRITES HOT_BYTES_READ HOT_BYTES_WRITTEN COLD_READS COLD_WRITES COLD_BYTES_READ COLD_BYTES_WRITTEN
------------ ----------- -------------- ----------- ---------- ---------- ---------- ---------- ------------ ------ ------ --------- --------- - ---------------- ----------- ---------------- ---------------- --------------------- ---- ---- ---------- ---------- -------------- ----------------- ---------- ----------- --------------- ------------------
           1         260       16777476   931438443      16384       1837   30097408   33554432 CONTROLFILE  UNPROT FINE   24-DEC-16 20-AUG-18 U rw-rw-rw-                  0                0                0                     0 COLD COLD          0          0            0                  0     3146179    13420526      5.1548E+10         2.1988E+11
           1         261       16777477   931438443      16384       1837   30097408   33554432 CONTROLFILE  UNPROT FINE   24-DEC-16 20-AUG-18 U rw-rw-rw-                  0                0                0                     0 COLD COLD          0          0            0                  0   283440487    13420559      1.9953E+13         2.1988E+11

--//再次证明读取的是控制文件.

3.疑问:
# rev /tmp/aa1 | cut -f1 -d'=' | rev | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
950272

--//我跟踪看到的读950272.950272/1024 = 928K.

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50          0        714
physical read total multi block requests                                       51          0        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55          0        714

SYS@xxxxx1> @ c.txt
'FLASHPCT;'||TRIM(CEIL(PERCENT_SPACE_USED))
-------------------------------------------------
flashpct;0

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50         73        714
physical read total multi block requests                                       51         15        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55   13828096        714

--//13828096/1024/1024 = 13.1875M,为什么呢?
# wc /tmp/aa1
  58  422 7310 /tmp/aa1

--//我重复使用strace做了跟踪:
# strace -p 24584 -t  -o /tmp/aa2
# strace -p 24584 -t  -c
Process 24584 attached - interrupt to quit
^CProcess 24584 detached
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
  -nan    0.000000           0         4           read
  -nan    0.000000           0         2           write
  -nan    0.000000           0         2           open
  -nan    0.000000           0         2           close
  -nan    0.000000           0         2           mmap
  -nan    0.000000           0        58           pread
  -nan    0.000000           0         4           semctl
  -nan    0.000000           0        20           getrusage
  -nan    0.000000           0        16           times
  -nan    0.000000           0        16           io_getevents
  -nan    0.000000           0        15           io_submit
  -nan    0.000000           0         2           semtimedop
------ ----------- ----------- --------- --------- ----------------
100.00    0.000000                   143           total

--//可以看到io_submit异步IO操作.等于15,正好和physical read total multi block requests的数值一致.
--//pread=58(与wc /tmp/aa1看到一致),io_submit=15,相加正好与physical read total IO requests=73一致.不知道是否是巧合.我对异步io操作的函数不熟悉.

16:45:26 io_submit(140402112221184, 8, {{0x7fb1e81f8210, 0, 0, 0, 256}, {0x7fb1e81f8480, 0, 0, 0, 258},
                                        {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 258},
                                        {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256},
                                        {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}}) = 8

--//猜测里面的256,257,258对应文件句柄.

# man io_submit
IO_SUBMIT(2)               Linux Programmer's Manual              IO_SUBMIT(2)

NAME
       io_submit - submit asynchronous I/O blocks for processing

SYNOPSIS
       #include <libaio.h>

int io_submit(aio_context_t ctx_id, long nr, struct iocb **iocbpp);

Link with -laio.

DESCRIPTION
       io_submit() queues nr I/O request blocks for processing in the AIO context ctx_id.  iocbpp should be an array of
       nr AIO control blocks, which will be submitted to context ctx_id.

# man io_getevents
IO_GETEVENTS(2)            Linux Programmer's Manual           IO_GETEVENTS(2)

NAME
       io_getevents - read asynchronous I/O events from the completion queue

SYNOPSIS
       #include <linux/time.h>
       #include <libaio.h>

int io_getevents(aio_context_t ctx_id, long min_nr, long nr,
                        struct io_event *events, struct timespec *timeout);

Link with -laio.

DESCRIPTION
       io_getevents()  attempts  to read at least min_nr events and up to nr events from the completion queue of the AIO
       context specified by ctx_id.  timeout specifies the amount of time to wait for events, where a NULL timeout waits
       until at least min_nr events have been seen.  Note that timeout is relative and will be updated if not NULL and
       the operation blocks.

# egrep 'io_submit|io_getevents' /tmp/aa2
16:45:26 io_submit(140402112221184, 8, {{0x7fb1e81f8210, 0, 0, 0, 256}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}}) = 8
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 81920, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 256}, {0x7fb1e81f86f0, 0, 0, 0, 258}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 49152, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 256}, {0x7fb1e81f86f0, 0, 0, 0, 258}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 49152, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 5, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}}) = 5
16:45:26 io_getevents(140402112221184, 5, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 49152, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 5
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}, {0x7fb1e81f9590, 0, 0, 0, 256}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}}, {0, 0}) = 1
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 257}, {0x7fb1e81f8bd0, 0, 0, 0, 256}, {0x7fb1e81f8e40, 0, 0, 0, 258}, {0x7fb1e81f90b0, 0, 0, 0, 257}, {0x7fb1e81f9320, 0, 0, 0, 256}, {0x7fb1e81f9590, 0, 0, 0, 258}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}}, {0, 0}) = 1
16:45:26 io_getevents(140402112221184, 8, 128, {{0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}}, {600, 0}) = 8
16:45:26 io_submit(140402112221184, 3, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}}) = 3
16:45:26 io_getevents(140402112221184, 3, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 114688, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 49152, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}}, {600, 0}) = 3
16:45:26 io_submit(140402112221184, 3, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 258}}) = 3
16:45:26 io_getevents(140402112221184, 3, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 81920, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}}, {600, 0}) = 3
16:45:26 io_submit(140402112221184, 6, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 256}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}}) = 6
16:45:26 io_getevents(140402112221184, 6, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 114688, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 6
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 257}, {0x7fb1e81f8480, 0, 0, 0, 258}, {0x7fb1e81f86f0, 0, 0, 0, 257}, {0x7fb1e81f8960, 0, 0, 0, 256}, {0x7fb1e81f8bd0, 0, 0, 0, 258}, {0x7fb1e81f8e40, 0, 0, 0, 257}, {0x7fb1e81f90b0, 0, 0, 0, 256}, {0x7fb1e81f9320, 0, 0, 0, 258}, {0x7fb1e81f9590, 0, 0, 0, 257}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 114688, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}}, {600, 0}) = 9
16:45:26 io_submit(140402112221184, 7, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}}) = 7
16:45:26 io_getevents(140402112221184, 7, 128, {{0x7fb1e81f8210, 0x7fb1e81f8210, 81920, 0}, {0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 16384, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}}, {600, 0}) = 7
16:45:26 io_submit(140402112221184, 9, {{0x7fb1e81f8210, 0, 0, 0, 258}, {0x7fb1e81f8480, 0, 0, 0, 257}, {0x7fb1e81f86f0, 0, 0, 0, 256}, {0x7fb1e81f8960, 0, 0, 0, 258}, {0x7fb1e81f8bd0, 0, 0, 0, 257}, {0x7fb1e81f8e40, 0, 0, 0, 256}, {0x7fb1e81f90b0, 0, 0, 0, 258}, {0x7fb1e81f9320, 0, 0, 0, 257}, {0x7fb1e81f9590, 0, 0, 0, 256}}) = 9
16:45:26 io_getevents(140402112221184, 9, 128, {{0x7fb1e81f86f0, 0x7fb1e81f86f0, 131072, 0}, {0x7fb1e81f8210, 0x7fb1e81f8210, 49152, 0}, {0x7fb1e81f8480, 0x7fb1e81f8480, 131072, 0}, {0x7fb1e81f8e40, 0x7fb1e81f8e40, 131072, 0}, {0x7fb1e81f9590, 0x7fb1e81f9590, 81920, 0}, {0x7fb1e81f8bd0, 0x7fb1e81f8bd0, 131072, 0}, {0x7fb1e81f9320, 0x7fb1e81f9320, 131072, 0}, {0x7fb1e81f90b0, 0x7fb1e81f90b0, 131072, 0}, {0x7fb1e81f8960, 0x7fb1e81f8960, 131072, 0}}, {600, 0}) = 9

--//我的感觉把io_getevents 函数里面的16384,131072加起来就是读取的字节总数.

# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
12877824

--//12877824+950272 = 13828096
--//^_^.正好和如下看到的一致.佩服一下自己..^_^.

SYS@xxxxx1> @ viewsess 'physical read total'
NAME                                                                   STATISTIC#      VALUE        SID
---------------------------------------------------------------------- ---------- ---------- ----------
physical read total IO requests                                                50         73        714
physical read total multi block requests                                       51         15        714
physical read total bytes optimized                                            53          0        714
physical read total bytes                                                      55   13828096        714

---//简单说明一下以上命令.# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g'| xargs echo| bc -l
1. grep 'io_getevents' /tmp/aa2 --//过滤出来io_getevents函数.
2. sed '1,$s/{/\^J/g'           --//将{替换为回车,^J在linux下先输入ctrl+v在按ctrl+enter就可以了,前面的\避免转义.
3. grep "^0x"                   --//过滤0x开头的行.
# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | head -1
0x7fb1e81f8210, 0x7fb1e81f8210, 16384, 0},

4.cut -f3 -d,                   --//以,为分隔符,取第3个字段.也就是里面16384.输出.
5.sed -e 's/$/+/g' -e '$s/+$//g'--//在每行结尾加入+,最后一行删除+号.

# grep 'io_getevents' /tmp/aa2 | sed '1,$s/{/\^J/g' | grep "^0x" | cut -f3 -d, | sed -e 's/$/+/g' -e '$s/+$//g' | tail -5
 81920+
 131072+
 131072+
 131072+
 131072

6.xargs echo                   --//也就是把多行变成一行,这里注意命令行缓存大小,一般情况下不会溢出的.
7.bc -l                        --//也就是计算.

--//顺便说一下bash shell编程一般不考虑执行效率,仅仅考虑快速编程,完成对应的工作.估计awk也许更好.

4.总结:
--//写这篇blog我参考以前遇到的问题,链接:http://blog.itpub.net/267265/viewspace-751787/,当时我应该看到读取调用函数是pread.
--//这个函数应该不支持异步IO.仅仅io_submit,io_getevents才表明系统执行异步IO.

--//也就是讲实际上就算是asm系统,实际上有1部分读取使用pread函数.而不是全部使用异步IO.

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