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author | Cyrill Gorcunov <gorcunov@openvz.org> | 2015-02-11 15:28:31 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-02-11 17:06:07 -0800 |
commit | 740a5ddb0e0d2ef3bd0a80ae027bf9d211b8c82d (patch) | |
tree | 2ec405da3ca76b1ee0bf452eeaa7406bb765c021 /Documentation/filesystems/proc.txt | |
parent | 10359213d05acf804558bda7cc9b8422a828d1cd (diff) | |
download | lwn-740a5ddb0e0d2ef3bd0a80ae027bf9d211b8c82d.tar.gz lwn-740a5ddb0e0d2ef3bd0a80ae027bf9d211b8c82d.zip |
Documentation/filesystems/proc.txt: describe /proc/<pid>/map_files
[akpm@linux-foundation.org: tweaks]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Calvin Owens <calvinowens@fb.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'Documentation/filesystems/proc.txt')
-rw-r--r-- | Documentation/filesystems/proc.txt | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index aae9dd13c91f..6d59ffe791ad 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -42,6 +42,7 @@ Table of Contents 3.6 /proc/<pid>/comm & /proc/<pid>/task/<tid>/comm 3.7 /proc/<pid>/task/<tid>/children - Information about task children 3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file + 3.9 /proc/<pid>/map_files - Information about memory mapped files 4 Configuring procfs 4.1 Mount options @@ -1763,6 +1764,28 @@ pair provide additional information particular to the objects they represent. with TIMER_ABSTIME option which will be shown in 'settime flags', but 'it_value' still exhibits timer's remaining time. +3.9 /proc/<pid>/map_files - Information about memory mapped files +--------------------------------------------------------------------- +This directory contains symbolic links which represent memory mapped files +the process is maintaining. Example output: + + | lr-------- 1 root root 64 Jan 27 11:24 333c600000-333c620000 -> /usr/lib64/ld-2.18.so + | lr-------- 1 root root 64 Jan 27 11:24 333c81f000-333c820000 -> /usr/lib64/ld-2.18.so + | lr-------- 1 root root 64 Jan 27 11:24 333c820000-333c821000 -> /usr/lib64/ld-2.18.so + | ... + | lr-------- 1 root root 64 Jan 27 11:24 35d0421000-35d0422000 -> /usr/lib64/libselinux.so.1 + | lr-------- 1 root root 64 Jan 27 11:24 400000-41a000 -> /usr/bin/ls + +The name of a link represents the virtual memory bounds of a mapping, i.e. +vm_area_struct::vm_start-vm_area_struct::vm_end. + +The main purpose of the map_files is to retrieve a set of memory mapped +files in a fast way instead of parsing /proc/<pid>/maps or +/proc/<pid>/smaps, both of which contain many more records. At the same +time one can open(2) mappings from the listings of two processes and +comparing their inode numbers to figure out which anonymous memory areas +are actually shared. + ------------------------------------------------------------------------------ Configuring procfs ------------------------------------------------------------------------------ |