经常有人问到如何在Unix下确定进程消耗的内存资源，以及为何Top工具的显示非常高。
有人说Top的输出不精确，这种说法是不确切的。实际上是Top输出显示的Oracle进程内存使用，包含了SGA部分。这也是SGA的意义所在。
SGA可以被共享，可以被所有进程所访问，在进程的寻址空间里就包含了SGA的大小。
至于如何更为精确的确定进程的内存消耗，本文简要介绍如下（在QuickIO下，你可能无法看到本文描述情况）：
1.系统平台及数据库版本
$ uname -a
SunOS billing 5.8 Generic_108528-23 sun4u sparc SUNW,Ultra-4
Sun Microsystems Inc. SunOS 5.8 Generic Patch October 2001
$ sqlplus "/ as sysdba"
SQL*Plus: Release 9.2.0.4.0 - Production on Sun Nov 28 10:48:00 2004
Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved.
Connected to:
Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
SQL> select * from v$version;
BANNER
----------------------------------------------------------------
Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
PL/SQL Release 9.2.0.4.0 - Production
CORE 9.2.0.3.0 Production
TNS for Solaris: Version 9.2.0.4.0 - Production
NLSRTL Version 9.2.0.4.0 - Production
SQL> show sga
Total System Global Area 253200688 bytes
Fixed Size 731440 bytes
Variable Size 167772160 bytes
Database Buffers 83886080 bytes
Redo Buffers 811008 bytes
SQL> exit
Disconnected from Oracle9i Enterprise Edition Release 9.2.0.4.0 - 64bit Production
With the Partitioning, OLAP and Oracle Data Mining options
JServer Release 9.2.0.4.0 - Production
2.Top输出
$ top
load averages: 0.12, 0.05, 0.04 billing 10:49:52
54 processes: 52 sleeping, 1 stopped, 1 on cpu
CPU states: 99.3% idle, 0.0% user, 0.3% kernel, 0.4% iowait, 0.0% swap
Memory: 2.0G real, 1.2G free, 404M swap in use, 5.1G swap free
PID USERNAME THR PR NCE SIZE RES STATE TIME FLTS CPU COMMAND
10027 oracle 1 58 0 2568K 1680K cpu03 0:00 0 0.09% top
10052 oracle 1 58 0 322M 275M sleep 21:18 0 0.01% oracle
11264 oracle 22 58 0 329M 275M sleep 59:01 0 0.00% oracle
10056 oracle 1 58 0 322M 275M sleep 3:04 0 0.00% oracle
11262 oracle 14 58 0 331M 270M sleep 73:55 0 0.00% oracle
11260 oracle 258 59 0 333M 274M sleep 52:46 0 0.00% oracle
11266 oracle 1 58 0 325M 276M sleep 26:50 0 0.00% oracle
10054 oracle 1 59 0 322M 275M sleep 18:27 0 0.00% oracle
23519 oracle 1 55 0 322M 278M sleep 0:50 0 0.00% oracle
11258 oracle 1 59 0 323M 271M sleep 0:31 0 0.00% oracle
11285 oracle 1 58 0 17.3M 3848K sleep 0:20 0 0.00% tnslsnr
11270 oracle 1 58 0 322M 271M sleep 0:06 0 0.00% oracle
2990 oracle 1 59 0 322M 276M sleep 0:04 0 0.00% oracle
9872 oracle 1 48 0 1880K 1192K sleep 0:00 0 0.00% ksh
23498 oracle 1 58 0 323M 278M sleep 0:00 0 0.00% oracle
3.Pmap输出及进程内存计算
$ ps -ef|grep ora_
oracle 9881 9872 0 10:49:57 pts/2 0:00 grep ora_
oracle 11258 1 0 Jul 19 ? 0:31 ora_pmon_hsbill
oracle 11260 1 0 Jul 19 ? 52:47 ora_dbw0_hsbill
oracle 11262 1 0 Jul 19 ? 73:55 ora_lgwr_hsbill
oracle 11264 1 0 Jul 19 ? 59:01 ora_ckpt_hsbill
oracle 11266 1 0 Jul 19 ? 26:50 ora_smon_hsbill
oracle 11268 1 0 Jul 19 ? 0:00 ora_reco_hsbill
oracle 11270 1 0 Jul 19 ? 0:06 ora_cjq0_hsbill
oracle 10054 1 0 Nov 02 ? 18:27 ora_j001_hsbill
oracle 10052 1 0 Nov 02 ? 21:19 ora_j000_hsbill
oracle 2990 1 0 Nov 25 ? 0:05 ora_j003_hsbill
oracle 10056 1 0 Nov 02 ? 3:04 ora_j002_hsbill
oracle 8879 1 0 09:54:32 ? 0:00 ora_j004_hsbill
$ pmap 11264
11264: ora_ckpt_hsbill
0000000100000000 53824K read/exec /opt/oracle/product/9.2.0/bin/oracle
000000010358E000 872K read/write/exec /opt/oracle/product/9.2.0/bin/oracle
0000000103668000 7968K read/write/exec [ heap ]
0000000380000000 266240K read/write/exec/shared [ ism shmid=0x64 ]
FFFFFFFF7C802000 8K read/write/exec [ anon ]
FFFFFFFF7C814000 8K read/write/exec [ anon ]
FFFFFFFF7C826000 8K read/write/exec [ anon ]
FFFFFFFF7C838000 8K read/write/exec [ anon ]
FFFFFFFF7C84A000 8K read/write/exec [ anon ]
FFFFFFFF7C85C000 8K read/write/exec [ anon ]
FFFFFFFF7C86E000 8K read/write/exec [ anon ]
FFFFFFFF7C880000 8K read/write/exec [ anon ]
FFFFFFFF7C892000 8K read/write/exec [ anon ]
FFFFFFFF7C8A4000 8K read/write/exec [ anon ]
FFFFFFFF7C8B6000 8K read/write/exec [ anon ]
FFFFFFFF7C8C8000 8K read/write/exec [ anon ]
FFFFFFFF7C8D6000 8K read/write/exec [ anon ]
FFFFFFFF7C8DA000 8K read/write/exec [ anon ]
FFFFFFFF7C8E8000 8K read/write/exec [ anon ]
FFFFFFFF7C8EC000 8K read/write/exec [ anon ]
FFFFFFFF7C8FA000 8K read/write/exec [ anon ]
FFFFFFFF7C8FE000 8K read/write/exec [ anon ]
FFFFFFFF7C90C000 8K read/write/exec [ anon ]
FFFFFFFF7C910000 8K read/write/exec [ anon ]
FFFFFFFF7C91E000 8K read/write/exec [ anon ]
FFFFFFFF7CA02000 8K read/write/exec [ anon ]
FFFFFFFF7CA10000 8K read/write/exec [ anon ]
FFFFFFFF7CA14000 8K read/write/exec [ anon ]
FFFFFFFF7CA22000 8K read/write/exec [ anon ]
FFFFFFFF7CA26000 8K read/write/exec [ anon ]
FFFFFFFF7CA34000 8K read/write/exec [ anon ]
FFFFFFFF7CA38000 8K read/write/exec [ anon ]
FFFFFFFF7CA46000 8K read/write/exec [ anon ]
FFFFFFFF7CA4A000 8K read/write/exec [ anon ]
FFFFFFFF7CA58000 8K read/write/exec [ anon ]
FFFFFFFF7CA5C000 8K read/write/exec [ anon ]
FFFFFFFF7CA6A000 8K read/write/exec [ anon ]
FFFFFFFF7CA6E000 8K read/write/exec [ anon ]
FFFFFFFF7CA7C000 8K read/write/exec [ anon ]
FFFFFFFF7CA80000 8K read/write/exec [ anon ]
FFFFFFFF7CA8E000 8K read/write/exec [ anon ]
FFFFFFFF7CA92000 8K read/write/exec [ anon ]
FFFFFFFF7CAA0000 8K read/write/exec [ anon ]
FFFFFFFF7CAA4000 8K read/write/exec [ anon ]
FFFFFFFF7CAB2000 8K read/write/exec [ anon ]
FFFFFFFF7CAB6000 8K read/write/exec [ anon ]
FFFFFFFF7CAC4000 8K read/write/exec [ anon ]
FFFFFFFF7CAC8000 8K read/write/exec [ anon ]
FFFFFFFF7CAD6000 8K read/write/exec [ anon ]
FFFFFFFF7CADA000 8K read/write/exec [ anon ]
FFFFFFFF7CAE8000 8K read/write/exec [ anon ]
FFFFFFFF7CAEC000 8K read/write/exec [ anon ]
FFFFFFFF7CAFA000 8K read/write/exec [ anon ]
FFFFFFFF7CAFE000 8K read/write/exec [ anon ]
FFFFFFFF7CB0C000 8K read/write/exec [ anon ]
FFFFFFFF7CB10000 8K read/write/exec [ anon ]
FFFFFFFF7CB1E000 8K read/write/exec [ anon ]
FFFFFFFF7CC00000 8K read/write/exec [ anon ]
FFFFFFFF7CD00000 24K read/exec /usr/lib/sparcv9/nss_files.so.1
FFFFFFFF7CE06000 8K read/write/exec /usr/lib/sparcv9/nss_files.so.1
FFFFFFFF7CF00000 8K read/write [ anon ]
FFFFFFFF7CF10000 8K read/write [ anon ]
FFFFFFFF7CF50000 8K read/write [ anon ]
FFFFFFFF7CF60000 16K read/write [ anon ]
FFFFFFFF7CF68000 32K read/write [ anon ]
FFFFFFFF7D000000 16K read/exec /usr/platform/sun4u/lib/sparcv9/libc_psr.so.1
FFFFFFFF7D100000 16K read/exec /usr/lib/sparcv9/libmp.so.2
FFFFFFFF7D204000 8K read/write/exec /usr/lib/sparcv9/libmp.so.2
FFFFFFFF7D300000 8K read/write/exec [ anon ]
FFFFFFFF7D400000 88K read/exec /usr/lib/sparcv9/libm.so.1
FFFFFFFF7D516000 8K read/write/exec /usr/lib/sparcv9/libm.so.1
FFFFFFFF7D600000 8K read/exec /usr/lib/sparcv9/libkstat.so.1
FFFFFFFF7D702000 8K read/write/exec /usr/lib/sparcv9/libkstat.so.1
FFFFFFFF7D800000 32K read/exec /usr/lib/sparcv9/librt.so.1
FFFFFFFF7D908000 8K read/write/exec /usr/lib/sparcv9/librt.so.1
FFFFFFFF7DA00000 32K read/exec /usr/lib/sparcv9/libaio.so.1
FFFFFFFF7DB08000 8K read/write/exec /usr/lib/sparcv9/libaio.so.1
FFFFFFFF7DC00000 720K read/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DDB4000 56K read/write/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DDC2000 8K read/write/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DF00000 8K read/write/exec [ anon ]
FFFFFFFF7E000000 32K read/exec /usr/lib/sparcv9/libgen.so.1
FFFFFFFF7E108000 8K read/write/exec /usr/lib/sparcv9/libgen.so.1
FFFFFFFF7E200000 672K read/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E3A8000 56K read/write/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E3B6000 40K read/write/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E400000 5328K read/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EA32000 384K read/write/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EA92000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EB00000 56K read/exec /usr/lib/sparcv9/libsocket.so.1
FFFFFFFF7EC0E000 16K read/write/exec /usr/lib/sparcv9/libsocket.so.1
FFFFFFFF7ED00000 8K read/write/exec [ anon ]
FFFFFFFF7EE00000 32K read/exec /opt/oracle/product/9.2.0/lib/libskgxn9.so
FFFFFFFF7EF06000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libskgxn9.so
FFFFFFFF7F000000 8K read/exec /opt/oracle/product/9.2.0/lib/libskgxp9.so
FFFFFFFF7F100000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libskgxp9.so
FFFFFFFF7F200000 8K read/exec /opt/oracle/product/9.2.0/lib/libodmd9.so
FFFFFFFF7F300000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libodmd9.so
FFFFFFFF7F400000 8K read/exec /usr/lib/sparcv9/libdl.so.1
FFFFFFFF7F500000 8K read/write/exec [ anon ]
FFFFFFFF7F600000 152K read/exec /usr/lib/sparcv9/ld.so.1
FFFFFFFF7F724000 16K read/write/exec /usr/lib/sparcv9/ld.so.1
FFFFFFFF7FFFA000 24K read/write [ stack ]
total 337360K
$
计算后台进程使用的内存资源:
337360K - 266240K = 71,120k
这就是一个进程所消耗的内存.
4.用户进程内存使用举例
$ ps -ef|grep LOCAL
oracle 10080 9872 0 11:00:25 pts/2 0:00 grep LOCAL
oracle 23498 1 0 Nov 25 ? 0:00 oraclehsbill (LOCAL=NO)
oracle 23519 1 0 Nov 25 ? 0:50 oraclehsbill (LOCAL=NO)
$ pmap 23519
23519: oraclehsbill (LOCAL=NO)
0000000100000000 53824K read/exec /opt/oracle/product/9.2.0/bin/oracle
000000010358E000 872K read/write/exec /opt/oracle/product/9.2.0/bin/oracle
0000000103668000 848K read/write/exec [ heap ]
0000000380000000 266240K read/write/exec/shared [ ism shmid=0x64 ]
FFFFFFFF7CC00000 8K read/write [ anon ]
FFFFFFFF7CC10000 8K read/write [ anon ]
FFFFFFFF7CC50000 136K read/write [ anon ]
FFFFFFFF7CC76000 40K read/write [ anon ]
FFFFFFFF7CD00000 8K read/write/exec [ anon ]
FFFFFFFF7CE00000 24K read/exec /usr/lib/sparcv9/nss_files.so.1
FFFFFFFF7CF06000 8K read/write/exec /usr/lib/sparcv9/nss_files.so.1
FFFFFFFF7D000000 16K read/exec /usr/platform/sun4u/lib/sparcv9/libc_psr.so.1
FFFFFFFF7D100000 16K read/exec /usr/lib/sparcv9/libmp.so.2
FFFFFFFF7D204000 8K read/write/exec /usr/lib/sparcv9/libmp.so.2
FFFFFFFF7D300000 8K read/write/exec [ anon ]
FFFFFFFF7D400000 88K read/exec /usr/lib/sparcv9/libm.so.1
FFFFFFFF7D516000 8K read/write/exec /usr/lib/sparcv9/libm.so.1
FFFFFFFF7D600000 8K read/exec /usr/lib/sparcv9/libkstat.so.1
FFFFFFFF7D702000 8K read/write/exec /usr/lib/sparcv9/libkstat.so.1
FFFFFFFF7D800000 32K read/exec /usr/lib/sparcv9/librt.so.1
FFFFFFFF7D908000 8K read/write/exec /usr/lib/sparcv9/librt.so.1
FFFFFFFF7DA00000 32K read/exec /usr/lib/sparcv9/libaio.so.1
FFFFFFFF7DB08000 8K read/write/exec /usr/lib/sparcv9/libaio.so.1
FFFFFFFF7DC00000 720K read/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DDB4000 56K read/write/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DDC2000 8K read/write/exec /usr/lib/sparcv9/libc.so.1
FFFFFFFF7DF00000 8K read/write/exec [ anon ]
FFFFFFFF7E000000 32K read/exec /usr/lib/sparcv9/libgen.so.1
FFFFFFFF7E108000 8K read/write/exec /usr/lib/sparcv9/libgen.so.1
FFFFFFFF7E200000 672K read/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E3A8000 56K read/write/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E3B6000 40K read/write/exec /usr/lib/sparcv9/libnsl.so.1
FFFFFFFF7E400000 5328K read/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EA32000 384K read/write/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EA92000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libjox9.so
FFFFFFFF7EB00000 56K read/exec /usr/lib/sparcv9/libsocket.so.1
FFFFFFFF7EC0E000 16K read/write/exec /usr/lib/sparcv9/libsocket.so.1
FFFFFFFF7ED00000 8K read/write/exec [ anon ]
FFFFFFFF7EE00000 32K read/exec /opt/oracle/product/9.2.0/lib/libskgxn9.so
FFFFFFFF7EF06000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libskgxn9.so
FFFFFFFF7F000000 8K read/exec /opt/oracle/product/9.2.0/lib/libskgxp9.so
FFFFFFFF7F100000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libskgxp9.so
FFFFFFFF7F200000 8K read/exec /opt/oracle/product/9.2.0/lib/libodmd9.so
FFFFFFFF7F300000 8K read/write/exec /opt/oracle/product/9.2.0/lib/libodmd9.so
FFFFFFFF7F400000 8K read/exec /usr/lib/sparcv9/libdl.so.1
FFFFFFFF7F500000 8K read/write/exec [ anon ]
FFFFFFFF7F600000 152K read/exec /usr/lib/sparcv9/ld.so.1
FFFFFFFF7F724000 16K read/write/exec /usr/lib/sparcv9/ld.so.1
FFFFFFFF7FFF2000 56K read/write [ stack ]
total 329968K
$
从PMAP的输出中我们可以看到进程所调用的库文件等，及其读写状态。