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Diffstat (limited to 'Documentation/admin-guide/cgroup-v2.rst')
| -rw-r--r-- | Documentation/admin-guide/cgroup-v2.rst | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst index 0e6c67ac585a..7f5b59d95fce 100644 --- a/Documentation/admin-guide/cgroup-v2.rst +++ b/Documentation/admin-guide/cgroup-v2.rst @@ -53,7 +53,8 @@ v1 is available under :ref:`Documentation/admin-guide/cgroup-v1/index.rst <cgrou 5-2. Memory 5-2-1. Memory Interface Files 5-2-2. Usage Guidelines - 5-2-3. Memory Ownership + 5-2-3. Reclaim Protection + 5-2-4. Memory Ownership 5-3. IO 5-3-1. IO Interface Files 5-3-2. Writeback @@ -1317,7 +1318,7 @@ PAGE_SIZE multiple when read back. smaller overages. Effective min boundary is limited by memory.min values of - all ancestor cgroups. If there is memory.min overcommitment + ancestor cgroups. If there is memory.min overcommitment (child cgroup or cgroups are requiring more protected memory than parent will allow), then each child cgroup will get the part of parent's protection proportional to its @@ -1326,9 +1327,6 @@ PAGE_SIZE multiple when read back. Putting more memory than generally available under this protection is discouraged and may lead to constant OOMs. - If a memory cgroup is not populated with processes, - its memory.min is ignored. - memory.low A read-write single value file which exists on non-root cgroups. The default is "0". @@ -1343,7 +1341,7 @@ PAGE_SIZE multiple when read back. smaller overages. Effective low boundary is limited by memory.low values of - all ancestor cgroups. If there is memory.low overcommitment + ancestor cgroups. If there is memory.low overcommitment (child cgroup or cgroups are requiring more protected memory than parent will allow), then each child cgroup will get the part of parent's protection proportional to its @@ -1515,6 +1513,10 @@ The following nested keys are defined. oom_group_kill The number of times a group OOM has occurred. + sock_throttled + The number of times network sockets associated with + this cgroup are throttled. + memory.events.local Similar to memory.events but the fields in the file are local to the cgroup i.e. not hierarchical. The file modified event @@ -1934,6 +1936,27 @@ memory - is necessary to determine whether a workload needs more memory; unfortunately, memory pressure monitoring mechanism isn't implemented yet. +Reclaim Protection +~~~~~~~~~~~~~~~~~~ + +The protection configured with "memory.low" or "memory.min" applies relatively +to the target of the reclaim (i.e. any of memory cgroup limits, proactive +memory.reclaim or global reclaim apparently located in the root cgroup). +The protection value configured for B applies unchanged to the reclaim +targeting A (i.e. caused by competition with the sibling E):: + + root - ... - A - B - C + \ ` D + ` E + +When the reclaim targets ancestors of A, the effective protection of B is +capped by the protection value configured for A (and any other intermediate +ancestors between A and the target). + +To express indifference about relative sibling protection, it is suggested to +use memory_recursiveprot. Configuring all descendants of a parent with finite +protection to "max" works but it may unnecessarily skew memory.events:low +field. Memory Ownership ~~~~~~~~~~~~~~~~ |