sched_ext: Remove SCX_OPS_PREPPING

The distinction between SCX_OPS_PREPPING and SCX_OPS_ENABLING is not used
anywhere and only adds confusion. Drop SCX_OPS_PREPPING.

Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index e8ab7e5ee2dde4a521bc532e3aa98b39c4e74dc4..daeb8446ff32c9f422390832e809f2e819c85ef8 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -779,7 +779,6 @@ enum scx_tg_flags {
 };
 
 enum scx_ops_enable_state {
-       SCX_OPS_PREPPING,
        SCX_OPS_ENABLING,
        SCX_OPS_ENABLED,
        SCX_OPS_DISABLING,
@@ -787,7 +786,6 @@ enum scx_ops_enable_state {
 };
 
 static const char *scx_ops_enable_state_str[] = {
-       [SCX_OPS_PREPPING]      = "prepping",
        [SCX_OPS_ENABLING]      = "enabling",
        [SCX_OPS_ENABLED]       = "enabled",
        [SCX_OPS_DISABLING]     = "disabling",
@@ -5016,12 +5014,12 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
        }
 
        /*
-        * Set scx_ops, transition to PREPPING and clear exit info to arm the
+        * Set scx_ops, transition to ENABLING and clear exit info to arm the
         * disable path. Failure triggers full disabling from here on.
         */
        scx_ops = *ops;
 
-       WARN_ON_ONCE(scx_ops_set_enable_state(SCX_OPS_PREPPING) !=
+       WARN_ON_ONCE(scx_ops_set_enable_state(SCX_OPS_ENABLING) !=
                     SCX_OPS_DISABLED);
 
        atomic_set(&scx_exit_kind, SCX_EXIT_NONE);
@@ -5174,23 +5172,6 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
         */
        preempt_disable();
 
-       /*
-        * From here on, the disable path must assume that tasks have ops
-        * enabled and need to be recovered.
-        *
-        * Transition to ENABLING fails iff the BPF scheduler has already
-        * triggered scx_bpf_error(). Returning an error code here would lose
-        * the recorded error information. Exit indicating success so that the
-        * error is notified through ops.exit() with all the details.
-        */
-       if (!scx_ops_tryset_enable_state(SCX_OPS_ENABLING, SCX_OPS_PREPPING)) {
-               preempt_enable();
-               spin_unlock_irq(&scx_tasks_lock);
-               WARN_ON_ONCE(atomic_read(&scx_exit_kind) == SCX_EXIT_NONE);
-               ret = 0;
-               goto err_disable_unlock_all;
-       }
-
        /*
         * We're fully committed and can't fail. The PREPPED -> ENABLED
         * transitions here are synchronized against sched_ext_free() through
@@ -5221,7 +5202,11 @@ static int scx_ops_enable(struct sched_ext_ops *ops, struct bpf_link *link)
        cpus_read_unlock();
        percpu_up_write(&scx_fork_rwsem);
 
-       /* see above ENABLING transition for the explanation on exiting with 0 */
+       /*
+        * Returning an error code here would lose the recorded error
+        * information. Exit indicating success so that the error is notified
+        * through ops.exit() with all the details.
+        */
        if (!scx_ops_tryset_enable_state(SCX_OPS_ENABLED, SCX_OPS_ENABLING)) {
                WARN_ON_ONCE(atomic_read(&scx_exit_kind) == SCX_EXIT_NONE);
                ret = 0;