sched_ext: Use btf_ids to resolve task_struct

Save the searching time during bpf_scx_init.

Signed-off-by: Tianchen Ding <dtcccc@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index fe8acae35166b401d11dfd5907fad68305f2ebe1..06c45d6c5be1f921f212c2b08959b63e1bc68c91 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -5324,7 +5324,6 @@ err_disable:
 
 extern struct btf *btf_vmlinux;
 static const struct btf_type *task_struct_type;
-static u32 task_struct_type_id;
 
 static bool set_arg_maybe_null(const char *op, int arg_n, int off, int size,
                               enum bpf_access_type type,
@@ -5376,7 +5375,7 @@ static bool set_arg_maybe_null(const char *op, int arg_n, int off, int size,
                 */
                info->reg_type = PTR_MAYBE_NULL | PTR_TO_BTF_ID | PTR_TRUSTED;
                info->btf = btf_vmlinux;
-               info->btf_id = task_struct_type_id;
+               info->btf_id = btf_tracing_ids[BTF_TRACING_TYPE_TASK];
 
                return true;
        }
@@ -5528,13 +5527,7 @@ static void bpf_scx_unreg(void *kdata, struct bpf_link *link)
 
 static int bpf_scx_init(struct btf *btf)
 {
-       s32 type_id;
-
-       type_id = btf_find_by_name_kind(btf, "task_struct", BTF_KIND_STRUCT);
-       if (type_id < 0)
-               return -EINVAL;
-       task_struct_type = btf_type_by_id(btf, type_id);
-       task_struct_type_id = type_id;
+       task_struct_type = btf_type_by_id(btf, btf_tracing_ids[BTF_TRACING_TYPE_TASK]);
 
        return 0;
 }