diff options
Diffstat (limited to 'Documentation/filesystems/proc.txt')
| -rw-r--r-- | Documentation/filesystems/proc.txt | 62 |
1 files changed, 61 insertions, 1 deletions
diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index aae9dd13c91f..a07ba61662ed 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -28,7 +28,7 @@ Table of Contents 1.6 Parallel port info in /proc/parport 1.7 TTY info in /proc/tty 1.8 Miscellaneous kernel statistics in /proc/stat - 1.9 Ext4 file system parameters + 1.9 Ext4 file system parameters 2 Modifying System Parameters @@ -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 @@ -144,6 +145,8 @@ Table 1-1: Process specific entries in /proc stack Report full stack trace, enable via CONFIG_STACKTRACE smaps a extension based on maps, showing the memory consumption of each mapping and flags associated with it + numa_maps an extension based on maps, showing the memory locality and + binding policy as well as mem usage (in pages) of each mapping. .............................................................................. For example, to get the status information of a process, all you have to do is @@ -488,12 +491,47 @@ To clear the bits for the file mapped pages associated with the process To clear the soft-dirty bit > echo 4 > /proc/PID/clear_refs +To reset the peak resident set size ("high water mark") to the process's +current value: + > echo 5 > /proc/PID/clear_refs + Any other value written to /proc/PID/clear_refs will have no effect. The /proc/pid/pagemap gives the PFN, which can be used to find the pageflags using /proc/kpageflags and number of times a page is mapped using /proc/kpagecount. For detailed explanation, see Documentation/vm/pagemap.txt. +The /proc/pid/numa_maps is an extension based on maps, showing the memory +locality and binding policy, as well as the memory usage (in pages) of +each mapping. The output follows a general format where mapping details get +summarized separated by blank spaces, one mapping per each file line: + +address policy mapping details + +00400000 default file=/usr/local/bin/app mapped=1 active=0 N3=1 kernelpagesize_kB=4 +00600000 default file=/usr/local/bin/app anon=1 dirty=1 N3=1 kernelpagesize_kB=4 +3206000000 default file=/lib64/ld-2.12.so mapped=26 mapmax=6 N0=24 N3=2 kernelpagesize_kB=4 +320621f000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 +3206220000 default file=/lib64/ld-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 +3206221000 default anon=1 dirty=1 N3=1 kernelpagesize_kB=4 +3206800000 default file=/lib64/libc-2.12.so mapped=59 mapmax=21 active=55 N0=41 N3=18 kernelpagesize_kB=4 +320698b000 default file=/lib64/libc-2.12.so +3206b8a000 default file=/lib64/libc-2.12.so anon=2 dirty=2 N3=2 kernelpagesize_kB=4 +3206b8e000 default file=/lib64/libc-2.12.so anon=1 dirty=1 N3=1 kernelpagesize_kB=4 +3206b8f000 default anon=3 dirty=3 active=1 N3=3 kernelpagesize_kB=4 +7f4dc10a2000 default anon=3 dirty=3 N3=3 kernelpagesize_kB=4 +7f4dc10b4000 default anon=2 dirty=2 active=1 N3=2 kernelpagesize_kB=4 +7f4dc1200000 default file=/anon_hugepage\040(deleted) huge anon=1 dirty=1 N3=1 kernelpagesize_kB=2048 +7fff335f0000 default stack anon=3 dirty=3 N3=3 kernelpagesize_kB=4 +7fff3369d000 default mapped=1 mapmax=35 active=0 N3=1 kernelpagesize_kB=4 + +Where: +"address" is the starting address for the mapping; +"policy" reports the NUMA memory policy set for the mapping (see vm/numa_memory_policy.txt); +"mapping details" summarizes mapping data such as mapping type, page usage counters, +node locality page counters (N0 == node0, N1 == node1, ...) and the kernel page +size, in KB, that is backing the mapping up. + 1.2 Kernel data --------------- @@ -1763,6 +1801,28 @@ 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 ------------------------------------------------------------------------------ |