[20181130]control file sequential read.txt

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[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. [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.