Merge branch 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

Pull cgroup updates from Tejun Heo:
 "Three minor cleanup patches"

* 'for-5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  Use kvmalloc in cgroups-v1
  cgroup: minor tweak for logic to get cgroup css
  cgroup: Replace a seq_printf() call by seq_puts() in cgroup_print_ss_mask()

kernel/cgroup/cgroup-v1.c

@@ -193,25 +193,6 @@ struct cgroup_pidlist {
 	struct delayed_work destroy_dwork;
 };
 
-/*
- * The following two functions "fix" the issue where there are more pids
- * than kmalloc will give memory for; in such cases, we use vmalloc/vfree.
- * TODO: replace with a kernel-wide solution to this problem
- */
-#define PIDLIST_TOO_LARGE(c) ((c) * sizeof(pid_t) > (PAGE_SIZE * 2))
-static void *pidlist_allocate(int count)
-{
-	if (PIDLIST_TOO_LARGE(count))
-		return vmalloc(array_size(count, sizeof(pid_t)));
-	else
-		return kmalloc_array(count, sizeof(pid_t), GFP_KERNEL);
-}
-
-static void pidlist_free(void *p)
-{
-	kvfree(p);
-}
-
 /*
  * Used to destroy all pidlists lingering waiting for destroy timer.  None
  * should be left afterwards.
@@ -244,7 +225,7 @@ static void cgroup_pidlist_destroy_work_fn(struct work_struct *work)
 	 */
 	if (!delayed_work_pending(dwork)) {
 		list_del(&l->links);
-		pidlist_free(l->list);
+		kvfree(l->list);
 		put_pid_ns(l->key.ns);
 		tofree = l;
 	}
@@ -365,7 +346,7 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
 	 * show up until sometime later on.
 	 */
 	length = cgroup_task_count(cgrp);
-	array = pidlist_allocate(length);
+	array = kvmalloc_array(length, sizeof(pid_t), GFP_KERNEL);
 	if (!array)
 		return -ENOMEM;
 	/* now, populate the array */
@@ -390,12 +371,12 @@ static int pidlist_array_load(struct cgroup *cgrp, enum cgroup_filetype type,
 
 	l = cgroup_pidlist_find_create(cgrp, type);
 	if (!l) {
-		pidlist_free(array);
+		kvfree(array);
 		return -ENOMEM;
 	}
 
 	/* store array, freeing old if necessary */
-	pidlist_free(l->list);
+	kvfree(l->list);
 	l->list = array;
 	l->length = length;
 	*lp = l;

kernel/cgroup/cgroup.c

@@ -488,7 +488,7 @@ static struct cgroup_subsys_state *cgroup_tryget_css(struct cgroup *cgrp,
 
 	rcu_read_lock();
 	css = cgroup_css(cgrp, ss);
-	if (!css || !css_tryget_online(css))
+	if (css && !css_tryget_online(css))
 		css = NULL;
 	rcu_read_unlock();
 
@@ -2894,7 +2894,7 @@ static void cgroup_print_ss_mask(struct seq_file *seq, u16 ss_mask)
 	do_each_subsys_mask(ss, ssid, ss_mask) {
 		if (printed)
 			seq_putc(seq, ' ');
-		seq_printf(seq, "%s", ss->name);
+		seq_puts(seq, ss->name);
 		printed = true;
 	} while_each_subsys_mask();
 	if (printed)