1NUMA_MAPS(5)               Linux Programmer's Manual              NUMA_MAPS(5)
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NAME

6       numa_maps - information about numa memory
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DESCRIPTION

9       The  file /proc/<pid>/numa_maps contrains information about each memory
10       area used by a given  process  allowing--among  other  information--the
11       determination of which nodes were used for the pages.
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13       numa_maps  is only read by programs or by shell commands, and not writ‐
14       ten to.  A read operation on the file will make  the  kernel  scan  the
15       memory  area  of a process to determine how memory is used. One line is
16       displayed for each memory area of the process.
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18       The numa_maps format is very simple. The first field shown on each line
19       is  the  starting  address  that  allows a correlation with output from
20       /proc/<pid/maps.  The second field shows the memory policy currently in
21       effect for this particular memory area.
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23       The  rest  of  the line contains series of informationi items about the
24       pages in the memory area.
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26   Possible information items
27       N<node>=<pages>
28                      The number of pages used on a node. The number of  pages
29                      includes only pages mapped by this process. If this is a
30                      shared mapping then other processes may have mapped dif‐
31                      ferent  pages  in  a  memory  area.  Note also that page
32                      migration may have temporarily unmapped pages. These may
33                      only  show  up  again after the process has attempted to
34                      reference these pages.
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36       file=<filename>
37                      The file backing the memory area. If COW (Copy-On-Write)
38                      pages  were  generated  then the memory area may contain
39                      additional anonymous pages.
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41       heap           Memory area is used for the heap.
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43       stack          Memory area is used for the stack.
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45       huge           Huge memory area. The page counts shown are  huge  pages
46                      and not regular sized pages.
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48       anon=<pages>   The number of anonymous page in the range.
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50       dirty=<pages>  Number of dirty pages
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52       mapped=<pages> Number of mapped pages for file backed files. Only shown
53                      if different from  the  count  of  anonymous  and  dirty
54                      pages.
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56       mapmax=<count> Maximum  mapcount  (number of processes mapping a single
57                      page) encountered during scan.  This may be used  as  an
58                      indicator  as  to the sharing occuring in a given memory
59                      area.
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61       swapcache=<count>
62                      Number of pages that have an  associated  entry  on  the
63                      swap device.
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65       active=<pages> The  number  of  pages on the active list (only shown if
66                      different from the number of pages  in  this  area).  If
67                      this  item  is  shown  then some inactive pages exist in
68                      that particular memory area that  may  be  removed  from
69                      memory by the swapper soon.
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71       writeback=<pages>
72                      Number  of pages that are currently being written out to
73                      disk.
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FILES

76       /proc/<pid>/numa_maps
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SEE ALSO

79       migratepages(8), numactl(8), cpuset(8), numactl(5)
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84Linux 2.6                        06 March 2006                    NUMA_MAPS(5)
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