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Diffstat (limited to 'Documentation/cgroups/memory.txt')
| -rw-r--r-- | Documentation/cgroups/memory.txt | 85 |
1 files changed, 84 insertions, 1 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 06eb6d957c83..6f3c598971fc 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -380,7 +380,7 @@ will be charged as a new owner of it. 5.2 stat file -memory.stat file includes following statistics +5.2.1 memory.stat file includes following statistics # per-memory cgroup local status cache - # of bytes of page cache memory. @@ -438,6 +438,89 @@ Note: file_mapped is accounted only when the memory cgroup is owner of page cache.) +5.2.2 memory.vmscan_stat + +memory.vmscan_stat includes statistics information for memory scanning and +freeing, reclaiming. The statistics shows memory scanning information since +memory cgroup creation and can be reset to 0 by writing 0 as + + #echo 0 > ../memory.vmscan_stat + +This file contains following statistics. + +[param]_[file_or_anon]_pages_by_[reason]_[under_heararchy] +[param]_elapsed_ns_by_[reason]_[under_hierarchy] + +For example, + + scanned_file_pages_by_limit indicates the number of scanned + file pages at vmscan. + +Now, 3 parameters are supported + + scanned - the number of pages scanned by vmscan + rotated - the number of pages activated at vmscan + freed - the number of pages freed by vmscan + +If "rotated" is high against scanned/freed, the memcg seems busy. + +Now, 2 reason are supported + + limit - the memory cgroup's limit + system - global memory pressure + softlimit + (global memory pressure not under softlimit is not handled now) + +When under_hierarchy is added in the tail, the number indicates the +total memcg scan of its children and itself. + +elapsed_ns is a elapsed time in nanosecond. This may include sleep time +and not indicates CPU usage. So, please take this as just showing +latency. + +Here is an example. + +# cat /cgroup/memory/A/memory.vmscan_stat +scanned_pages_by_limit 9471864 +scanned_anon_pages_by_limit 6640629 +scanned_file_pages_by_limit 2831235 +rotated_pages_by_limit 4243974 +rotated_anon_pages_by_limit 3971968 +rotated_file_pages_by_limit 272006 +freed_pages_by_limit 2318492 +freed_anon_pages_by_limit 962052 +freed_file_pages_by_limit 1356440 +elapsed_ns_by_limit 351386416101 +scanned_pages_by_system 0 +scanned_anon_pages_by_system 0 +scanned_file_pages_by_system 0 +rotated_pages_by_system 0 +rotated_anon_pages_by_system 0 +rotated_file_pages_by_system 0 +freed_pages_by_system 0 +freed_anon_pages_by_system 0 +freed_file_pages_by_system 0 +elapsed_ns_by_system 0 +scanned_pages_by_limit_under_hierarchy 9471864 +scanned_anon_pages_by_limit_under_hierarchy 6640629 +scanned_file_pages_by_limit_under_hierarchy 2831235 +rotated_pages_by_limit_under_hierarchy 4243974 +rotated_anon_pages_by_limit_under_hierarchy 3971968 +rotated_file_pages_by_limit_under_hierarchy 272006 +freed_pages_by_limit_under_hierarchy 2318492 +freed_anon_pages_by_limit_under_hierarchy 962052 +freed_file_pages_by_limit_under_hierarchy 1356440 +elapsed_ns_by_limit_under_hierarchy 351386416101 +scanned_pages_by_system_under_hierarchy 0 +scanned_anon_pages_by_system_under_hierarchy 0 +scanned_file_pages_by_system_under_hierarchy 0 +rotated_pages_by_system_under_hierarchy 0 +rotated_anon_pages_by_system_under_hierarchy 0 +rotated_file_pages_by_system_under_hierarchy 0 +freed_pages_by_system_under_hierarchy 0 +freed_anon_pages_by_system_under_hierarchy 0 +freed_file_pages_by_system_under_hierarchy 0 +elapsed_ns_by_system_under_hierarchy 0 + 5.3 swappiness Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. |