pmap -x [PROCESS ID]  

e.g.:

[root@ ~]# pmap -x 19771
19771:   nginx: worker process      
Address           Kbytes     RSS   Dirty Mode   Mapping
0000000000400000     668     420       0 r-x--  nginx
00000000006a6000      56      56      52 rw---  nginx
00000000006b4000      60      16      16 rw---    [ anon ]
000000000f4c4000    1468    1080    1080 rw---    [ anon ]
00000034f3c00000     112      40       0 r-x--  ld-2.5.so
00000034f3e1b000       4       4       4 r----  ld-2.5.so
00000034f3e1c000       4       4       4 rw---  ld-2.5.so
00000034f4000000    1336     280       0 r-x--  libc-2.5.so
00000034f414e000    2044       0       0 -----  libc-2.5.so
00000034f434d000      16      16       8 r----  libc-2.5.so
00000034f4351000       4       4       4 rw---  libc-2.5.so
00000034f4352000      20      20      20 rw---    [ anon ]
00000034f4400000       8       4       0 r-x--  libdl-2.5.so
00000034f4402000    2048       0       0 -----  libdl-2.5.so
00000034f4602000       4       4       4 r----  libdl-2.5.so
00000034f4603000       4       4       4 rw---  libdl-2.5.so
00000034f4800000     108      36       0 r-x--  libpcre.so.0.0.1
00000034f481b000    2048       0       0 -----  libpcre.so.0.0.1
00000034f4a1b000       4       4       4 rw---  libpcre.so.0.0.1
00000034f4c00000      80      52       0 r-x--  libz.so.1.2.3
00000034f4c14000    2044       0       0 -----  libz.so.1.2.3
00000034f4e13000       4       4       4 rw---  libz.so.1.2.3
00000034f5400000     236       0       0 r-x--  libsepol.so.1
00000034f543b000    2048       0       0 -----  libsepol.so.1
00000034f563b000       4       4       4 rw---  libsepol.so.1
00000034f563c000      40       0       0 rw---    [ anon ]
00000034f5800000      84       0       0 r-x--  libselinux.so.1
00000034f5815000    2048       0       0 -----  libselinux.so.1
00000034f5a15000       8       8       8 rw---  libselinux.so.1
00000034f5a17000       4       4       4 rw---    [ anon ]
00000034f6800000      36       4       0 r-x--  libcrypt-2.5.so
00000034f6809000    2044       0       0 -----  libcrypt-2.5.so
00000034f6a08000       4       4       4 r----  libcrypt-2.5.so
00000034f6a09000       4       4       4 rw---  libcrypt-2.5.so
00000034f6a0a000     184       0       0 rw---    [ anon ]
00000034f6c00000    1204       8       0 r-x--  libcrypto.so.0.9.8e
00000034f6d2d000    2044       0       0 -----  libcrypto.so.0.9.8e
00000034f6f2c000     132      84      20 rw---  libcrypto.so.0.9.8e
00000034f6f4d000      16      16      16 rw---    [ anon ]
00000034f7000000     176       0       0 r-x--  libgssapi_krb5.so.2.2
00000034f702c000    2048       0       0 -----  libgssapi_krb5.so.2.2
00000034f722c000       8       8       8 rw---  libgssapi_krb5.so.2.2
00000034f7800000     280       4       0 r-x--  libssl.so.0.9.8e
00000034f7846000    2048       0       0 -----  libssl.so.0.9.8e
00000034f7a46000      24      16      12 rw---  libssl.so.0.9.8e
00000034f9000000       8       0       0 r-x--  libkeyutils-1.2.so
00000034f9002000    2044       0       0 -----  libkeyutils-1.2.so
00000034f9201000       4       4       4 rw---  libkeyutils-1.2.so
00000034f9800000      68       0       0 r-x--  libresolv-2.5.so
00000034f9811000    2048       0       0 -----  libresolv-2.5.so
00000034f9a11000       4       4       4 r----  libresolv-2.5.so
00000034f9a12000       4       4       4 rw---  libresolv-2.5.so
00000034f9a13000       8       0       0 rw---    [ anon ]
00000034fa000000       8       0       0 r-x--  libcom_err.so.2.1
00000034fa002000    2044       0       0 -----  libcom_err.so.2.1
00000034fa201000       4       4       4 rw---  libcom_err.so.2.1
00000034fa800000     144       0       0 r-x--  libk5crypto.so.3.1
00000034fa824000    2044       0       0 -----  libk5crypto.so.3.1
00000034faa23000       8       8       8 rw---  libk5crypto.so.3.1
00000034fac00000      32       0       0 r-x--  libkrb5support.so.0.1
00000034fac08000    2044       0       0 -----  libkrb5support.so.0.1
00000034fae07000       4       4       4 rw---  libkrb5support.so.0.1
00000034fb800000     580       0       0 r-x--  libkrb5.so.3.3
00000034fb891000    2048       0       0 -----  libkrb5.so.3.3
00000034fba91000      16      16      12 rw---  libkrb5.so.3.3
00002b643b45e000       4       4       4 rw---    [ anon ]
00002b643b471000      32      32      32 rw---    [ anon ]
00002b643b479000      40      20       0 r-x--  libnss_files-2.5.so
00002b643b483000    2044       0       0 -----  libnss_files-2.5.so
00002b643b682000       4       4       4 r----  libnss_files-2.5.so
00002b643b683000       4       4       4 rw---  libnss_files-2.5.so
00002b643b684000       4       4       4 rw-s-  zero (deleted)
00002b643b685000   19612   19600   19600 rw---    [ anon ]
00007fff7a86a000      84      24      24 rw---    [ stack ]
ffffffffff600000    8192       0       0 -----    [ anon ]
----------------  ------  ------  ------
total kB           70052   21948   20996

其中RSS(Resident set size,常驻内存)是进程实际占用的内存数

Kbytes是程序可以访问的虚拟内存大小。

关于Dirty:

Pages of memory are either Free (available to allocate), Active (in use), or Inactive. Inactive pages of memory are either dirty or clean, depending on if it has been selected for removal yet or not. An inactive, dirty page is no longer in use, but is not yet available for re-use. The operating system must scan for dirty pages, and decide to deallocate them. After they have been guaranteed sync'd to disk, an inactive page my be “clean,” or ready for re-use.