Merge branch 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "All trivial changes - simplification, typo fix and adding
  cond_resched() in a netclassid update loop"

* 'for-4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup, netclassid: add a preemption point to write_classid
  rdmacg: fix a typo in rdmacg documentation
  cgroup: Simplify cgroup_ancestor

3 files changed, 5 insertions, 13 deletions

diff --git a/Documentation/cgroup-v1/rdma.txt b/Documentation/cgroup-v1/rdma.txt
index af618171e0eb..9bdb7fd03f83 100644
--- a/Documentation/cgroup-v1/rdma.txt
+++ b/Documentation/cgroup-v1/rdma.txt
@@ -27,7 +27,7 @@ cgroup.
 Currently user space applications can easily take away all the rdma verb
 specific resources such as AH, CQ, QP, MR etc. Due to which other applications
 in other cgroup or kernel space ULPs may not even get chance to allocate any
-rdma resources. This can leads to service unavailability.
+rdma resources. This can lead to service unavailability.
 
 Therefore RDMA controller is needed through which resource consumption
 of processes can be limited. Through this controller different rdma
diff --git a/include/linux/cgroup.h b/include/linux/cgroup.h
index b8bcbdeb2eac..b622d6608605 100644
--- a/include/linux/cgroup.h
+++ b/include/linux/cgroup.h
@@ -569,20 +569,11 @@ static inline bool cgroup_is_descendant(struct cgroup *cgrp,
 static inline struct cgroup *cgroup_ancestor(struct cgroup *cgrp,
 					     int ancestor_level)
 {
-	struct cgroup *ptr;
-
 	if (cgrp->level < ancestor_level)
 		return NULL;
-
-	for (ptr = cgrp;
-	     ptr && ptr->level > ancestor_level;
-	     ptr = cgroup_parent(ptr))
-		;
-
-	if (ptr && ptr->level == ancestor_level)
-		return ptr;
-
-	return NULL;
+	while (cgrp && cgrp->level > ancestor_level)
+		cgrp = cgroup_parent(cgrp);
+	return cgrp;
 }
 
 /**
diff --git a/net/core/netclassid_cgroup.c b/net/core/netclassid_cgroup.c
index 5e4f04004a49..7bf833598615 100644
--- a/net/core/netclassid_cgroup.c
+++ b/net/core/netclassid_cgroup.c
@@ -106,6 +106,7 @@ static int write_classid(struct cgroup_subsys_state *css, struct cftype *cft,
 		iterate_fd(p->files, 0, update_classid_sock,
 			   (void *)(unsigned long)cs->classid);
 		task_unlock(p);
+		cond_resched();
 	}
 	css_task_iter_end(&it);