This is a note to let you know that I've just added the patch titled
cgroup/cpuset: Skip spread flags update on v2
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cgroup-cpuset-skip-spread-flags-update-on-v2.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 964498edc3a87e450ee8c127ce2700db134d67de
Author: Waiman Long <longman@xxxxxxxxxx>
Date: Sat Nov 12 17:19:38 2022 -0500
cgroup/cpuset: Skip spread flags update on v2
[ Upstream commit 18f9a4d47527772515ad6cbdac796422566e6440 ]
Cpuset v2 has no spread flags to set. So we can skip spread
flags update if cpuset v2 is being used. Also change the name to
cpuset_update_task_spread_flags() to indicate that there are multiple
spread flags.
Signed-off-by: Waiman Long <longman@xxxxxxxxxx>
Signed-off-by: Tejun Heo <tj@xxxxxxxxxx>
Stable-dep-of: 42a11bf5c543 ("cgroup/cpuset: Make cpuset_fork() handle CLONE_INTO_CGROUP properly")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c
index fb895eaf3a7c3..3d254498eb275 100644
--- a/kernel/cgroup/cpuset.c
+++ b/kernel/cgroup/cpuset.c
@@ -450,11 +450,15 @@ static void guarantee_online_mems(struct cpuset *cs, nodemask_t *pmask)
/*
* update task's spread flag if cpuset's page/slab spread flag is set
*
- * Call with callback_lock or cpuset_rwsem held.
+ * Call with callback_lock or cpuset_rwsem held. The check can be skipped
+ * if on default hierarchy.
*/
-static void cpuset_update_task_spread_flag(struct cpuset *cs,
+static void cpuset_update_task_spread_flags(struct cpuset *cs,
struct task_struct *tsk)
{
+ if (cgroup_subsys_on_dfl(cpuset_cgrp_subsys))
+ return;
+
if (is_spread_page(cs))
task_set_spread_page(tsk);
else
@@ -1941,7 +1945,7 @@ static void update_tasks_flags(struct cpuset *cs)
css_task_iter_start(&cs->css, 0, &it);
while ((task = css_task_iter_next(&it)))
- cpuset_update_task_spread_flag(cs, task);
+ cpuset_update_task_spread_flags(cs, task);
css_task_iter_end(&it);
}
@@ -2274,7 +2278,7 @@ static void cpuset_attach(struct cgroup_taskset *tset)
WARN_ON_ONCE(set_cpus_allowed_ptr(task, cpus_attach));
cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to);
- cpuset_update_task_spread_flag(cs, task);
+ cpuset_update_task_spread_flags(cs, task);
}
/*
