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authorLinus Torvalds <torvalds@linux-foundation.org>2022-01-11 09:14:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2022-01-11 09:14:37 -0800
commitea1ca66d3cc07b00241fcee82328f387359f32f5 (patch)
treeeaa2b866471d2268ef93f5e2b4b4365d0e4f0ee3 /kernel
parent68514dacf2715d11b91ca50d88de047c086fea9c (diff)
parentd4296faebd337e5f76c0fddb815de33d2b0ad118 (diff)
Merge branch 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo: "Nothing too interesting. The only two noticeable changes are a subtle cpuset behavior fix and trace event id field being expanded to u64 from int. Most others are code cleanups" * 'for-5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cpuset: convert 'allowed' in __cpuset_node_allowed() to be boolean cgroup/rstat: check updated_next only for root cgroup: rstat: explicitly put loop variant in while cgroup: return early if it is already on preloaded list cgroup/cpuset: Don't let child cpusets restrict parent in default hierarchy cgroup: Trace event cgroup id fields should be u64 cgroup: fix a typo in comment cgroup: get the wrong css for css_alloc() during cgroup_init_subsys() cgroup: rstat: Mark benign data race to silence KCSAN
Diffstat (limited to 'kernel')
-rw-r--r--kernel/cgroup/cgroup.c6
-rw-r--r--kernel/cgroup/cpuset.c16
-rw-r--r--kernel/cgroup/rstat.c51
3 files changed, 31 insertions, 42 deletions
diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index 581ca5a11aaa..b31e1465868a 100644
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2651,11 +2651,11 @@ void cgroup_migrate_add_src(struct css_set *src_cset,
if (src_cset->dead)
return;
- src_cgrp = cset_cgroup_from_root(src_cset, dst_cgrp->root);
-
if (!list_empty(&src_cset->mg_preload_node))
return;
+ src_cgrp = cset_cgroup_from_root(src_cset, dst_cgrp->root);
+
WARN_ON(src_cset->mg_src_cgrp);
WARN_ON(src_cset->mg_dst_cgrp);
WARN_ON(!list_empty(&src_cset->mg_tasks));
@@ -5743,7 +5743,7 @@ static void __init cgroup_init_subsys(struct cgroup_subsys *ss, bool early)
/* Create the root cgroup state for this subsystem */
ss->root = &cgrp_dfl_root;
- css = ss->css_alloc(cgroup_css(&cgrp_dfl_root.cgrp, ss));
+ css = ss->css_alloc(NULL);
/* We don't handle early failures gracefully */
BUG_ON(IS_ERR(css));
init_and_link_css(css, ss, &cgrp_dfl_root.cgrp);
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index d0e163a02099..dc653ab26e50 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -616,19 +616,11 @@ static int validate_change(struct cpuset *cur, struct cpuset *trial)
struct cpuset *c, *par;
int ret;
- rcu_read_lock();
-
- /* Each of our child cpusets must be a subset of us */
- ret = -EBUSY;
- cpuset_for_each_child(c, css, cur)
- if (!is_cpuset_subset(c, trial))
- goto out;
-
- /* Remaining checks don't apply to root cpuset */
- ret = 0;
+ /* The checks don't apply to root cpuset */
if (cur == &top_cpuset)
- goto out;
+ return 0;
+ rcu_read_lock();
par = parent_cs(cur);
/* On legacy hierarchy, we must be a subset of our parent cpuset. */
@@ -3536,7 +3528,7 @@ static struct cpuset *nearest_hardwall_ancestor(struct cpuset *cs)
bool __cpuset_node_allowed(int node, gfp_t gfp_mask)
{
struct cpuset *cs; /* current cpuset ancestors */
- int allowed; /* is allocation in zone z allowed? */
+ bool allowed; /* is allocation in zone z allowed? */
unsigned long flags;
if (in_interrupt())
diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c
index 1486768f2318..9d331ba44870 100644
--- a/kernel/cgroup/rstat.c
+++ b/kernel/cgroup/rstat.c
@@ -35,7 +35,7 @@ void cgroup_rstat_updated(struct cgroup *cgrp, int cpu)
* instead of NULL, we can tell whether @cgrp is on the list by
* testing the next pointer for NULL.
*/
- if (cgroup_rstat_cpu(cgrp, cpu)->updated_next)
+ if (data_race(cgroup_rstat_cpu(cgrp, cpu)->updated_next))
return;
raw_spin_lock_irqsave(cpu_lock, flags);
@@ -88,6 +88,7 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos,
struct cgroup *root, int cpu)
{
struct cgroup_rstat_cpu *rstatc;
+ struct cgroup *parent;
if (pos == root)
return NULL;
@@ -96,10 +97,14 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos,
* We're gonna walk down to the first leaf and visit/remove it. We
* can pick whatever unvisited node as the starting point.
*/
- if (!pos)
+ if (!pos) {
pos = root;
- else
+ /* return NULL if this subtree is not on-list */
+ if (!cgroup_rstat_cpu(pos, cpu)->updated_next)
+ return NULL;
+ } else {
pos = cgroup_parent(pos);
+ }
/* walk down to the first leaf */
while (true) {
@@ -115,33 +120,25 @@ static struct cgroup *cgroup_rstat_cpu_pop_updated(struct cgroup *pos,
* However, due to the way we traverse, @pos will be the first
* child in most cases. The only exception is @root.
*/
- if (rstatc->updated_next) {
- struct cgroup *parent = cgroup_parent(pos);
-
- if (parent) {
- struct cgroup_rstat_cpu *prstatc;
- struct cgroup **nextp;
-
- prstatc = cgroup_rstat_cpu(parent, cpu);
- nextp = &prstatc->updated_children;
- while (true) {
- struct cgroup_rstat_cpu *nrstatc;
-
- nrstatc = cgroup_rstat_cpu(*nextp, cpu);
- if (*nextp == pos)
- break;
- WARN_ON_ONCE(*nextp == parent);
- nextp = &nrstatc->updated_next;
- }
- *nextp = rstatc->updated_next;
- }
+ parent = cgroup_parent(pos);
+ if (parent) {
+ struct cgroup_rstat_cpu *prstatc;
+ struct cgroup **nextp;
- rstatc->updated_next = NULL;
- return pos;
+ prstatc = cgroup_rstat_cpu(parent, cpu);
+ nextp = &prstatc->updated_children;
+ while (*nextp != pos) {
+ struct cgroup_rstat_cpu *nrstatc;
+
+ nrstatc = cgroup_rstat_cpu(*nextp, cpu);
+ WARN_ON_ONCE(*nextp == parent);
+ nextp = &nrstatc->updated_next;
+ }
+ *nextp = rstatc->updated_next;
}
- /* only happens for @root */
- return NULL;
+ rstatc->updated_next = NULL;
+ return pos;
}
/* see cgroup_rstat_flush() */