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Diffstat (limited to 'tools/perf/util/bpf_skel/off_cpu.bpf.c')
-rw-r--r--tools/perf/util/bpf_skel/off_cpu.bpf.c18
1 files changed, 14 insertions, 4 deletions
diff --git a/tools/perf/util/bpf_skel/off_cpu.bpf.c b/tools/perf/util/bpf_skel/off_cpu.bpf.c
index c4ba2bcf179f..38e3b287dbb2 100644
--- a/tools/perf/util/bpf_skel/off_cpu.bpf.c
+++ b/tools/perf/util/bpf_skel/off_cpu.bpf.c
@@ -94,6 +94,8 @@ const volatile bool has_prev_state = false;
const volatile bool needs_cgroup = false;
const volatile bool uses_cgroup_v1 = false;
+int perf_subsys_id = -1;
+
/*
* Old kernel used to call it task_struct->state and now it's '__state'.
* Use BPF CO-RE "ignored suffix rule" to deal with it like below:
@@ -119,11 +121,19 @@ static inline __u64 get_cgroup_id(struct task_struct *t)
{
struct cgroup *cgrp;
- if (uses_cgroup_v1)
- cgrp = BPF_CORE_READ(t, cgroups, subsys[perf_event_cgrp_id], cgroup);
- else
- cgrp = BPF_CORE_READ(t, cgroups, dfl_cgrp);
+ if (!uses_cgroup_v1)
+ return BPF_CORE_READ(t, cgroups, dfl_cgrp, kn, id);
+
+ if (perf_subsys_id == -1) {
+#if __has_builtin(__builtin_preserve_enum_value)
+ perf_subsys_id = bpf_core_enum_value(enum cgroup_subsys_id,
+ perf_event_cgrp_id);
+#else
+ perf_subsys_id = perf_event_cgrp_id;
+#endif
+ }
+ cgrp = BPF_CORE_READ(t, cgroups, subsys[perf_subsys_id], cgroup);
return BPF_CORE_READ(cgrp, kn, id);
}