diff options
Diffstat (limited to 'Documentation/cgroups/memory.txt')
| -rw-r--r-- | Documentation/cgroups/memory.txt | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 3aaf7870a93e..5403b8cb1d09 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -72,6 +72,7 @@ Brief summary of control files. memory.move_charge_at_immigrate # set/show controls of moving charges memory.oom_control # set/show oom controls. memory.numa_stat # show the number of memory usage per numa node + memory.dangling_memcgs # show debugging information about dangling groups memory.kmem.limit_in_bytes # set/show hard limit for kernel memory memory.kmem.usage_in_bytes # show current kernel memory allocation @@ -581,6 +582,21 @@ unevictable=<total anon pages> N0=<node 0 pages> N1=<node 1 pages> ... And we have total = file + anon + unevictable. +5.7 dangling_memcgs + +This file will only be ever present in the root cgroup, if the option +CONFIG_MEMCG_DEBUG_ASYNC_DESTROY is set. When a memcg is destroyed, the memory +consumed by it may not be immediately freed. This is because when some +extensions are used, such as swap or kernel memory, objects can outlive the +group and hold a reference to it. + +If this is the case, the dangling_memcgs file will show information about what +are the memcgs still alive, and which references are still preventing it to be +freed. There is nothing wrong with that, but it is very useful when debugging, +to know where this memory is being held. This is a developer-oriented debugging +facility only, and no guarantees of interface stability will be given. The file +is read-only, and has the sole purpose of displaying information. + 6. Hierarchy support The memory controller supports a deep hierarchy and hierarchical accounting. |