From 1815775e74541d7b498c0baf15726ad3d1247abf Mon Sep 17 00:00:00 2001 From: Wei Yang <richard.weiyang@gmail.com> Date: Tue, 14 Dec 2021 00:46:07 +0000 Subject: [PATCH] cgroup: return early if it is already on preloaded list If a cset is already on preloaded list, this means we have already setup this cset properly for migration. This patch just relocates the root cgrp lookup which isn't used anyway when the cset is already on the preloaded list. [tj@kernel.org: rephrase the commit log] Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org> --- kernel/cgroup/cgroup.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c index f522cee8e6506..4f77bf1eaf9ff 100644 --- a/kernel/cgroup/cgroup.c +++ b/kernel/cgroup/cgroup.c @@ -2650,11 +2650,11 @@ 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));