From: Tejun Heo <tj@kernel.org>
Date: Sat, 29 Jun 2013 04:08:27 +0000 (-0700)
Subject: cgroup: remove gratuituous BUG_ON()s from rebind_subsystems()
X-Git-Tag: accepted/tizen/common/20141203.182822~1610^2~60
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a698b4488ab98deef6c3beeba3e27fea17650132;p=platform%2Fkernel%2Flinux-arm64.git

cgroup: remove gratuituous BUG_ON()s from rebind_subsystems()

rebind_subsystems() performs santiy checks even on subsystems which
aren't specified to be added or removed and the checks aren't all that
useful given that these are in a very cold path while the violations
they check would trip up in much hotter paths.

Let's remove these from rebind_subsystems().

Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
---

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 2a8cf1a..345fac8 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1077,15 +1077,6 @@ static int rebind_subsystems(struct cgroupfs_root *root,
 			/* subsystem is now free - drop reference on module */
 			module_put(ss->module);
 			root->subsys_mask &= ~bit;
-		} else if (bit & root->subsys_mask) {
-			/* Subsystem state should already exist */
-			BUG_ON(!cgrp->subsys[i]);
-#ifdef CONFIG_MODULE_UNLOAD
-			BUG_ON(ss->module && !module_refcount(ss->module));
-#endif
-		} else {
-			/* Subsystem state shouldn't exist */
-			BUG_ON(cgrp->subsys[i]);
 		}
 	}