* ``/proc/pid/pagemap``. This file lets a userspace process find out which
physical frame each virtual page is mapped to. It contains one 64-bit
value for each virtual page, containing the following data (from
- fs/proc/task_mmu.c, above pagemap_read):
+ ``fs/proc/task_mmu.c``, above pagemap_read):
* Bits 0-54 page frame number (PFN) if present
* Bits 0-4 swap type if swapped
precisely which pages are mapped (or in swap) and comparing mapped
pages between processes.
- Efficient users of this interface will use /proc/pid/maps to
+ Efficient users of this interface will use ``/proc/pid/maps`` to
determine which areas of memory are actually mapped and llseek to
skip over unmapped regions.
memory cgroup each page is charged to, indexed by PFN. Only available when
CONFIG_MEMCG is set.
-Short descriptions to the page flags:
-=====================================
+Short descriptions to the page flags
+====================================
0 - LOCKED
- page is being locked for exclusive access, eg. by undergoing read/write IO
+ page is being locked for exclusive access, e.g. by undergoing read/write IO
7 - SLAB
page is managed by the SLAB/SLOB/SLUB/SLQB kernel memory allocator
When compound page is used, SLUB/SLQB will only set this flag on the head
ie. for file backed page: (in-memory data revision >= on-disk one)
4 - DIRTY
page has been written to, hence contains new data
- ie. for file backed page: (in-memory data revision > on-disk one)
+ i.e. for file backed page: (in-memory data revision > on-disk one)
8 - WRITEBACK
page is being synced to disk
page is in the active LRU list
18 - UNEVICTABLE
page is in the unevictable (non-)LRU list It is somehow pinned and
- not a candidate for LRU page reclaims, eg. ramfs pages,
+ not a candidate for LRU page reclaims, e.g. ramfs pages,
shmctl(SHM_LOCK) and mlock() memory segments
2 - REFERENCED
page has been referenced since last LRU list enqueue/requeue
12 - ANON
a memory mapped page that is not part of a file
13 - SWAPCACHE
- page is mapped to swap space, ie. has an associated swap entry
+ page is mapped to swap space, i.e. has an associated swap entry
14 - SWAPBACKED
page is backed by swap/RAM