Signed-off-by: Suleiman Souhlal <suleiman@xxxxxxxxxx> --- Documentation/cgroups/memory.txt | 33 ++++++++++++++++++++++++++++++++- 1 files changed, 32 insertions(+), 1 deletions(-) diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index 06eb6d9..277cf25 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -220,7 +220,37 @@ caches are dropped. But as mentioned above, global LRU can do swapout memory from it for sanity of the system's memory management state. You can't forbid it by cgroup. -2.5 Reclaim +2.5 Kernel Memory + +A cgroup's kernel memory is accounted into its memory.usage_in_bytes and +is also shown in memory.stat as kernel_memory. Kernel memory does not get +counted towards the root cgroup's memory.usage_in_bytes, but still +appears in its kernel_memory. + +Upon cgroup deletion, all the remaining kernel memory gets moved to the +root cgroup. + +An accounted kernel memory allocation may trigger reclaim in that cgroup, +and may also OOM. + +Currently only slab memory allocated without __GFP_NOACCOUNT and +__GFP_NOFAIL gets accounted to the current process' cgroup. + +2.5.1 Slab + +Slab gets accounted on a per-page basis, which is done by using per-cgroup +kmem_caches. These per-cgroup kmem_caches get created on-demand, the first +time a specific kmem_cache gets used by a cgroup. + +Slab memory that cannot be attributed to a cgroup gets charged to the root +cgroup. + +A per-cgroup kmem_cache is named like the original, with the cgroup's name +in parethesis. +When a kmem_cache gets migrated to the root cgroup, "dead" is appended to +its name, to indicated that it is not going to be used for new allocations. + +2.6 Reclaim Each cgroup maintains a per cgroup LRU which has the same structure as global VM. When a cgroup goes over its limit, we first try @@ -396,6 +426,7 @@ active_anon - # of bytes of anonymous and swap cache memory on active inactive_file - # of bytes of file-backed memory on inactive LRU list. active_file - # of bytes of file-backed memory on active LRU list. unevictable - # of bytes of memory that cannot be reclaimed (mlocked etc). +kernel_memory - # of bytes of kernel memory. # status considering hierarchy (see memory.use_hierarchy settings) -- 1.7.3.1 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>