[PATCH 5/9] RFC cgroup/cpuset-v1: Add deprecation warnings to mem_exclusive and mem_hardwall

From: Michal Koutný
Date: Tue Mar 04 2025 - 11:04:49 EST


The concept of exclusive memory affinity may require complex approaches
like with cpuset v2 cpu partitions. There is so far no implementation in
cpuset v2.
Specific kernel memory affinity may cause unintended (global)
bottlenecks like kmem limits.

Cc: Paul Menage <menage@xxxxxxxxxx>
Cc: Paul Jackson <pj@xxxxxxx>
Signed-off-by: Michal Koutný <mkoutny@xxxxxxxx>
---
kernel/cgroup/cpuset-v1.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/kernel/cgroup/cpuset-v1.c b/kernel/cgroup/cpuset-v1.c
index 9aae6dabb0b56..05d3622ea41e5 100644
--- a/kernel/cgroup/cpuset-v1.c
+++ b/kernel/cgroup/cpuset-v1.c
@@ -424,9 +424,11 @@ static int cpuset_write_u64(struct cgroup_subsys_state *css, struct cftype *cft,
retval = cpuset_update_flag(CS_CPU_EXCLUSIVE, cs, val);
break;
case FILE_MEM_EXCLUSIVE:
+ pr_warn_once("cpuset.%s is deprecated\n", cft->name);
retval = cpuset_update_flag(CS_MEM_EXCLUSIVE, cs, val);
break;
case FILE_MEM_HARDWALL:
+ pr_warn_once("cpuset.%s is deprecated\n", cft->name);
retval = cpuset_update_flag(CS_MEM_HARDWALL, cs, val);
break;
case FILE_SCHED_LOAD_BALANCE:
--
2.48.1