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-rw-r--r-- | Documentation/cgroups/memory.txt | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index b6ed61c9585..7c163477fcd 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -52,8 +52,10 @@ Brief summary of control files. tasks # attach a task(thread) and show list of threads cgroup.procs # show list of processes cgroup.event_control # an interface for event_fd() - memory.usage_in_bytes # show current memory(RSS+Cache) usage. - memory.memsw.usage_in_bytes # show current memory+Swap usage + memory.usage_in_bytes # show current res_counter usage for memory + (See 5.5 for details) + memory.memsw.usage_in_bytes # show current res_counter usage for memory+Swap + (See 5.5 for details) memory.limit_in_bytes # set/show limit of memory usage memory.memsw.limit_in_bytes # set/show limit of memory+Swap usage memory.failcnt # show the number of memory usage hits limits @@ -453,6 +455,15 @@ memory under it will be reclaimed. You can reset failcnt by writing 0 to failcnt file. # echo 0 > .../memory.failcnt +5.5 usage_in_bytes + +For efficiency, as other kernel components, memory cgroup uses some optimization +to avoid unnecessary cacheline false sharing. usage_in_bytes is affected by the +method and doesn't show 'exact' value of memory(and swap) usage, it's an fuzz +value for efficient access. (Of course, when necessary, it's synchronized.) +If you want to know more exact memory usage, you should use RSS+CACHE(+SWAP) +value in memory.stat(see 5.2). + 6. Hierarchy support The memory controller supports a deep hierarchy and hierarchical accounting. |