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authorTejun Heo <tj@kernel.org>2018-12-28 10:31:07 -0800
committerTejun Heo <tj@kernel.org>2018-12-28 10:34:12 -0800
commit3fc9c12d27b4ded4f1f761a800558dab2e6bbac5 (patch)
tree93db5bb4c9028449057db754f83058bb7593aefa
parente250d91d65750a0c0c62483ac4f9f357e7317617 (diff)
downloadlwn-3fc9c12d27b4ded4f1f761a800558dab2e6bbac5.tar.gz
lwn-3fc9c12d27b4ded4f1f761a800558dab2e6bbac5.zip
cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param
It can be useful to inhibit all cgroup1 hierarchies especially during transition and for debugging. cgroup_no_v1 can block hierarchies with controllers which leaves out the named hierarchies. Expand it to cover the named hierarchies so that "cgroup_no_v1=all,named" disables all cgroup1 hierarchies. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Marcin Pawlowski <mpawlowski@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org>
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt8
-rw-r--r--kernel/cgroup/cgroup-v1.c14
2 files changed, 19 insertions, 3 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 81d1d5a74728..8b7652449228 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -486,10 +486,14 @@
cut the overhead, others just disable the usage. So
only cgroup_disable=memory is actually worthy}
- cgroup_no_v1= [KNL] Disable one, multiple, all cgroup controllers in v1
- Format: { controller[,controller...] | "all" }
+ cgroup_no_v1= [KNL] Disable cgroup controllers and named hierarchies in v1
+ Format: { { controller | "all" | "named" }
+ [,{ controller | "all" | "named" }...] }
Like cgroup_disable, but only applies to cgroup v1;
the blacklisted controllers remain available in cgroup2.
+ "all" blacklists all controllers and "named" disables
+ named mounts. Specifying both "all" and "named" disables
+ all v1 hierarchies.
cgroup.memory= [KNL] Pass options to the cgroup memory controller.
Format: <string>
diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c
index 51063e7a93c2..583b969b0c0e 100644
--- a/kernel/cgroup/cgroup-v1.c
+++ b/kernel/cgroup/cgroup-v1.c
@@ -27,6 +27,9 @@
/* Controllers blocked by the commandline in v1 */
static u16 cgroup_no_v1_mask;
+/* disable named v1 mounts */
+static bool cgroup_no_v1_named;
+
/*
* pidlist destructions need to be flushed on cgroup destruction. Use a
* separate workqueue as flush domain.
@@ -963,6 +966,10 @@ static int parse_cgroupfs_options(char *data, struct cgroup_sb_opts *opts)
}
if (!strncmp(token, "name=", 5)) {
const char *name = token + 5;
+
+ /* blocked by boot param? */
+ if (cgroup_no_v1_named)
+ return -ENOENT;
/* Can't specify an empty name */
if (!strlen(name))
return -EINVAL;
@@ -1292,7 +1299,12 @@ static int __init cgroup_no_v1(char *str)
if (!strcmp(token, "all")) {
cgroup_no_v1_mask = U16_MAX;
- break;
+ continue;
+ }
+
+ if (!strcmp(token, "named")) {
+ cgroup_no_v1_named = true;
+ continue;
}
for_each_subsys(ss, i) {