bpf: use rcu_read_lock_dont_migrate() for bpf_prog_run_array_cg()

Use rcu_read_lock_dont_migrate() and rcu_read_unlock_migrate() in
bpf_prog_run_array_cg to obtain better performance when PREEMPT_RCU is
not enabled.

Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Link: https://lore.kernel.org/r/20250821090609.42508-7-dongml2@chinatelecom.cn
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 180b630..9912c7b 100644 (file)
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -71,8 +71,7 @@ bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
        u32 func_ret;
 
        run_ctx.retval = retval;
-       migrate_disable();
-       rcu_read_lock();
+       rcu_read_lock_dont_migrate();
        array = rcu_dereference(cgrp->effective[atype]);
        item = &array->items[0];
        old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
@@ -88,8 +87,7 @@ bpf_prog_run_array_cg(const struct cgroup_bpf *cgrp,
                item++;
        }
        bpf_reset_run_ctx(old_run_ctx);
-       rcu_read_unlock();
-       migrate_enable();
+       rcu_read_unlock_migrate();
        return run_ctx.retval;
 }