Merge branch 'pci/switchtec'

[linux.git] / Documentation / admin-guide / cgroup-v2.rst

diff --git a/Documentation/admin-guide/cgroup-v2.rst b/Documentation/admin-guide/cgroup-v2.rst
index 0fa8c0e615c2853587e2a87fa396fb5dbac321bb..5361ebec33612d62e8078e630d35e517db2a73b0 100644 (file)
--- a/Documentation/admin-guide/cgroup-v2.rst
+++ b/Documentation/admin-guide/cgroup-v2.rst
@@ -615,8 +615,8 @@ on an IO device and is an example of this type.
 Protections
 -----------
 
-A cgroup is protected to be allocated upto the configured amount of
-the resource if the usages of all its ancestors are under their
+A cgroup is protected upto the configured amount of the resource
+as long as the usages of all its ancestors are under their
 protected levels.  Protections can be hard guarantees or best effort
 soft boundaries.  Protections can also be over-committed in which case
 only upto the amount available to the parent is protected among
@@ -1096,7 +1096,10 @@ PAGE_SIZE multiple when read back.
        is within its effective min boundary, the cgroup's memory
        won't be reclaimed under any conditions. If there is no
        unprotected reclaimable memory available, OOM killer
-       is invoked.
+       is invoked. Above the effective min boundary (or
+       effective low boundary if it is higher), pages are reclaimed
+       proportionally to the overage, reducing reclaim pressure for
+       smaller overages.
 
        Effective min boundary is limited by memory.min values of
        all ancestor cgroups. If there is memory.min overcommitment
@@ -1118,7 +1121,10 @@ PAGE_SIZE multiple when read back.
        Best-effort memory protection.  If the memory usage of a
        cgroup is within its effective low boundary, the cgroup's
        memory won't be reclaimed unless memory can be reclaimed
-       from unprotected cgroups.
+       from unprotected cgroups.  Above the effective low boundary (or
+       effective min boundary if it is higher), pages are reclaimed
+       proportionally to the overage, reducing reclaim pressure for
+       smaller overages.
 
        Effective low boundary is limited by memory.low values of
        all ancestor cgroups. If there is memory.low overcommitment
@@ -2482,8 +2488,10 @@ system performance due to overreclaim, to the point where the feature
 becomes self-defeating.
 
 The memory.low boundary on the other hand is a top-down allocated
-reserve.  A cgroup enjoys reclaim protection when it's within its low,
-which makes delegation of subtrees possible.
+reserve.  A cgroup enjoys reclaim protection when it's within its
+effective low, which makes delegation of subtrees possible. It also
+enjoys having reclaim pressure proportional to its overage when
+above its effective low.
 
 The original high boundary, the hard limit, is defined as a strict
 limit that can not budge, even if the OOM killer has to be called.