[PATCH v2 15/23] mm: introduce bpf_task_is_oom_victim() kfunc

Roman Gushchin
2025-10-27T23:22:38Z

Export tsk_is_oom_victim() helper as a BPF kfunc.
It's very useful to avoid redundant oom kills.

Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
---
mm/oom_kill.c | 14 ++++++++++++++
1 file changed, 14 insertions(+)

diff --git a/mm/oom_kill.c b/mm/oom_kill.c
index 72a346261c79..90bb86dee3cf 100644
--- a/mm/oom_kill.c
+++ b/mm/oom_kill.c
@@ -1397,11 +1397,25 @@ __bpf_kfunc int bpf_out_of_memory(struct mem_cgroup *memcg__nullable,
return ret;
}

+/**
+ * bpf_task_is_oom_victim - Check if the task has been marked as an OOM victim
+ * @task: task to check
+ *
+ * Returns true if the task has been previously selected by the OOM killer
+ * to be killed. It's expected that the task will be destroyed soon and some
+ * memory will be freed, so maybe no additional actions required.
+ */
+__bpf_kfunc bool bpf_task_is_oom_victim(struct task_struct *task)
+{
+ return tsk_is_oom_victim(task);
+}
+
__bpf_kfunc_end_defs();

BTF_KFUNCS_START(bpf_oom_kfuncs)
BTF_ID_FLAGS(func, bpf_oom_kill_process, KF_SLEEPABLE | KF_TRUSTED_ARGS)
BTF_ID_FLAGS(func, bpf_out_of_memory, KF_SLEEPABLE | KF_TRUSTED_ARGS)
+BTF_ID_FLAGS(func, bpf_task_is_oom_victim, KF_TRUSTED_ARGS)
BTF_KFUNCS_END(bpf_oom_kfuncs)

BTF_SET_START(bpf_oom_declare_oom_kfuncs)
--
2.51.0