cgroup, docs: add a note about returning EBUSY in some cases
Subsystems (2)
PATCH 1/1 cgroup, docs: add a note about returning EBUSY in some cases
Explicitly document EBUSY returned by writing into cgroup.procs if controllers are enabled; and writing into cgroup.subtree_control if there are attached processes.
The return code might be slightly surprising, and because there is nothing obviously better, let's document it at least.
Signed-off-by Roman Gushchin <[email protected]>
Cc Tejun Heo <[email protected]>
--- Documentation/cgroup-v2.txt | 6 ++++++ 1 file changed, 6 insertions(+)
Documentation/cgroup-v2.txt +6 -0
@@ -799,6 +799,9 @@ All cgroup core files are prefixed with "cgroup." When delegating a sub-hierarchy, write access to this file should be granted along with the containing directory. + If the target cgroup has enabled controllers, writing to this + file will fail with EBUSY. + In a threaded cgroup, reading this file fails with EOPNOTSUPP as all the processes belong to the thread root. Writing is supported and moves every thread of the process to the cgroup.
@@ -850,6 +853,9 @@ All cgroup core files are prefixed with "cgroup." the last one is effective. When multiple enable and disable operations are specified, either all succeed or all fail. + If the cgroup has attached tasks, writing to this file will + fail with EBUSY. + cgroup.events A read-only flat-keyed file which exists on non-root cgroups. The following entries are defined. Unless specified
Signature · 1 line
2.14.3