Operation and Maintenance
Linux Operation and Maintenance
Detailed explanation of pmap command for Linux performance testing
Detailed explanation of pmap command for Linux performance testing
The pmap command is used to display the memory status of one or more processes. This article will share with you the detailed explanation of the Linux performance test pmap command. Friends who need it can refer to it
Name:
pmap - report memory map of a process(查看进程的内存映像信息)
Usage
pmap [ -x | -d ] [ -q ] pids...
pmap -VOption meaning
-x extended Show the extended format. 显示扩展格式
-d device Show the device format. 显示设备格式
-q quiet Do not display some header/footer lines. 不显示头尾行
-V show version Displays version of program. 显示版本Extended format and device format fields:
Address: start address of map 映像起始地址
Kbytes: size of map in kilobytes 映像大小
RSS: resident set size in kilobytes 驻留集大小
Dirty: dirty pages (both shared and private) in kilobytes 脏页大小
Mode: permissions on map 映像权限: r=read, w=write, x=execute, s=shared, p=private (copy on write)
Mapping: file backing the map , or '[ anon ]' for allocated memory, or '[ stack ]' for the program stack. 映像支持文件,[anon]为已分配内存 [stack]为程序堆栈
Offset: offset into the file 文件偏移
Device: device name (major:minor) 设备名Example:
View the device format of process 1
[root@C44 ~]# pmap -d 1 1: init [5] Address Kbytes Mode Offset Device Mapping 00934000 88 r-x-- 0000000000000000 008:00005 ld-2.3.4.so 0094a000 4 r---- 0000000000015000 008:00005 ld-2.3.4.so 0094b000 4 rw--- 0000000000016000 008:00005 ld-2.3.4.so 0094e000 1188 r-x-- 0000000000000000 008:00005 libc-2.3.4.so 00a77000 8 r---- 0000000000129000 008:00005 libc-2.3.4.so 00a79000 8 rw--- 000000000012b000 008:00005 libc-2.3.4.so 00a7b000 8 rw--- 0000000000a7b000 000:00000 [ anon ] 00a85000 52 r-x-- 0000000000000000 008:00005 libsepol.so.1 00a92000 4 rw--- 000000000000c000 008:00005 libsepol.so.1 00a93000 32 rw--- 0000000000a93000 000:00000 [ anon ] 00d9d000 52 r-x-- 0000000000000000 008:00005 libselinux.so.1 00daa000 4 rw--- 000000000000d000 008:00005 libselinux.so.1 08048000 28 r-x-- 0000000000000000 008:00005 init 0804f000 4 rw--- 0000000000007000 008:00005 init 084e1000 132 rw--- 00000000084e1000 000:00000 [ anon ] b7f5d000 8 rw--- 00000000b7f5d000 000:00000 [ anon ] bffee000 72 rw--- 00000000bffee000 000:00000 [ stack ] ffffe000 4 ----- 0000000000000000 000:00000 [ anon ] mapped: 1700K writeable/private: 276K shared: 0K [root@C44 ~]#
The value of the last line
mapped indicates the size of the virtual address space mapped by the process, which is pre-allocated by the process The size of virtual memory, that is, the vsz
writeable/private output from ps indicates the size of the private address space occupied by the process, which is the size of the memory actually used by the process.
shared indicates that the process is shared with other processes. The memory size
View the device format of process 1, do not display the first and last lines
[root@C44 ~]# pmap -d -q 1 1: init [5] 00934000 88 r-x-- 0000000000000000 008:00005 ld-2.3.4.so 0094a000 4 r---- 0000000000015000 008:00005 ld-2.3.4.so 0094b000 4 rw--- 0000000000016000 008:00005 ld-2.3.4.so 0094e000 1188 r-x-- 0000000000000000 008:00005 libc-2.3.4.so 00a77000 8 r---- 0000000000129000 008:00005 libc-2.3.4.so 00a79000 8 rw--- 000000000012b000 008:00005 libc-2.3.4.so 00a7b000 8 rw--- 0000000000a7b000 000:00000 [ anon ] 00a85000 52 r-x-- 0000000000000000 008:00005 libsepol.so.1 00a92000 4 rw--- 000000000000c000 008:00005 libsepol.so.1 00a93000 32 rw--- 0000000000a93000 000:00000 [ anon ] 00d9d000 52 r-x-- 0000000000000000 008:00005 libselinux.so.1 00daa000 4 rw--- 000000000000d000 008:00005 libselinux.so.1 08048000 28 r-x-- 0000000000000000 008:00005 init 0804f000 4 rw--- 0000000000007000 008:00005 init 084e1000 132 rw--- 00000000084e1000 000:00000 [ anon ] b7f5d000 8 rw--- 00000000b7f5d000 000:00000 [ anon ] bffee000 72 rw--- 00000000bffee000 000:00000 [ stack ] ffffe000 4 ----- 0000000000000000 000:00000 [ anon ] [root@C44 ~]#
View the extended format of process 1
[root@C44 ~]# pmap -x 1 1: init [5] Address Kbytes RSS Anon Locked Mode Mapping 00934000 88 - - - r-x-- ld-2.3.4.so 0094a000 4 - - - r---- ld-2.3.4.so 0094b000 4 - - - rw--- ld-2.3.4.so 0094e000 1188 - - - r-x-- libc-2.3.4.so 00a77000 8 - - - r---- libc-2.3.4.so 00a79000 8 - - - rw--- libc-2.3.4.so 00a7b000 8 - - - rw--- [ anon ] 00a85000 52 - - - r-x-- libsepol.so.1 00a92000 4 - - - rw--- libsepol.so.1 00a93000 32 - - - rw--- [ anon ] 00d9d000 52 - - - r-x-- libselinux.so.1 00daa000 4 - - - rw--- libselinux.so.1 08048000 28 - - - r-x-- init 0804f000 4 - - - rw--- init 084e1000 132 - - - rw--- [ anon ] b7f5d000 8 - - - rw--- [ anon ] bffee000 72 - - - rw--- [ stack ] ffffe000 4 - - - ----- [ anon ] -------- ------- ------- ------- ------- total kB 1700 - - - [root@C44 ~]#
Display the last line of the device format of process 3066 in a loop, with an interval of 2 seconds,
[root@C44 ~]# while true; do pmap -d 3066 | tail -1; sleep 2; done mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K mapped: 5412K writeable/private: 2028K shared: 0K
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