sched_ext: Extract scx_dump_cpu() from scx_dump_state()

Factor out the per-CPU state dump logic from the for_each_possible_cpu
loop in scx_dump_state() into a new scx_dump_cpu() helper to improve
readability. No functional change.

Signed-off-by: Changwoo Min <changwoo@igalia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 11893f00be06439d2942e5490f082c6303eb8f79..fff3c8ab017519e0896afb3cc6a9197a715ca022 100644 (file)
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -6254,6 +6254,94 @@ static void scx_dump_task(struct scx_sched *sch, struct seq_buf *s, struct scx_d
        }
 }
 
+static void scx_dump_cpu(struct scx_sched *sch, struct seq_buf *s,
+                        struct scx_dump_ctx *dctx, int cpu,
+                        bool dump_all_tasks)
+{
+       struct rq *rq = cpu_rq(cpu);
+       struct rq_flags rf;
+       struct task_struct *p;
+       struct seq_buf ns;
+       size_t avail, used;
+       char *buf;
+       bool idle;
+
+       rq_lock_irqsave(rq, &rf);
+
+       idle = list_empty(&rq->scx.runnable_list) &&
+               rq->curr->sched_class == &idle_sched_class;
+
+       if (idle && !SCX_HAS_OP(sch, dump_cpu))
+               goto next;
+
+       /*
+        * We don't yet know whether ops.dump_cpu() will produce output
+        * and we may want to skip the default CPU dump if it doesn't.
+        * Use a nested seq_buf to generate the standard dump so that we
+        * can decide whether to commit later.
+        */
+       avail = seq_buf_get_buf(s, &buf);
+       seq_buf_init(&ns, buf, avail);
+
+       dump_newline(&ns);
+       dump_line(&ns, "CPU %-4d: nr_run=%u flags=0x%x cpu_rel=%d ops_qseq=%lu ksync=%lu",
+                 cpu, rq->scx.nr_running, rq->scx.flags,
+                 rq->scx.cpu_released, rq->scx.ops_qseq,
+                 rq->scx.kick_sync);
+       dump_line(&ns, "          curr=%s[%d] class=%ps",
+                 rq->curr->comm, rq->curr->pid,
+                 rq->curr->sched_class);
+       if (!cpumask_empty(rq->scx.cpus_to_kick))
+               dump_line(&ns, "  cpus_to_kick   : %*pb",
+                         cpumask_pr_args(rq->scx.cpus_to_kick));
+       if (!cpumask_empty(rq->scx.cpus_to_kick_if_idle))
+               dump_line(&ns, "  idle_to_kick   : %*pb",
+                         cpumask_pr_args(rq->scx.cpus_to_kick_if_idle));
+       if (!cpumask_empty(rq->scx.cpus_to_preempt))
+               dump_line(&ns, "  cpus_to_preempt: %*pb",
+                         cpumask_pr_args(rq->scx.cpus_to_preempt));
+       if (!cpumask_empty(rq->scx.cpus_to_wait))
+               dump_line(&ns, "  cpus_to_wait   : %*pb",
+                         cpumask_pr_args(rq->scx.cpus_to_wait));
+       if (!cpumask_empty(rq->scx.cpus_to_sync))
+               dump_line(&ns, "  cpus_to_sync   : %*pb",
+                         cpumask_pr_args(rq->scx.cpus_to_sync));
+
+       used = seq_buf_used(&ns);
+       if (SCX_HAS_OP(sch, dump_cpu)) {
+               ops_dump_init(&ns, "  ");
+               SCX_CALL_OP(sch, dump_cpu, rq, dctx, cpu, idle);
+               ops_dump_exit();
+       }
+
+       /*
+        * If idle && nothing generated by ops.dump_cpu(), there's
+        * nothing interesting. Skip.
+        */
+       if (idle && used == seq_buf_used(&ns))
+               goto next;
+
+       /*
+        * $s may already have overflowed when $ns was created. If so,
+        * calling commit on it will trigger BUG.
+        */
+       if (avail) {
+               seq_buf_commit(s, seq_buf_used(&ns));
+               if (seq_buf_has_overflowed(&ns))
+                       seq_buf_set_overflow(s);
+       }
+
+       if (rq->curr->sched_class == &ext_sched_class &&
+           (dump_all_tasks || scx_task_on_sched(sch, rq->curr)))
+               scx_dump_task(sch, s, dctx, rq, rq->curr, '*');
+
+       list_for_each_entry(p, &rq->scx.runnable_list, scx.runnable_node)
+               if (dump_all_tasks || scx_task_on_sched(sch, p))
+                       scx_dump_task(sch, s, dctx, rq, p, ' ');
+next:
+       rq_unlock_irqrestore(rq, &rf);
+}
+
 /*
  * Dump scheduler state. If @dump_all_tasks is true, dump all tasks regardless
  * of which scheduler they belong to. If false, only dump tasks owned by @sch.
@@ -6274,7 +6362,6 @@ static void scx_dump_state(struct scx_sched *sch, struct scx_exit_info *ei,
        };
        struct seq_buf s;
        struct scx_event_stats events;
-       char *buf;
        int cpu;
 
        guard(raw_spinlock_irqsave)(&scx_dump_lock);
@@ -6314,87 +6401,7 @@ static void scx_dump_state(struct scx_sched *sch, struct scx_exit_info *ei,
        dump_line(&s, "----------");
 
        for_each_possible_cpu(cpu) {
-               struct rq *rq = cpu_rq(cpu);
-               struct rq_flags rf;
-               struct task_struct *p;
-               struct seq_buf ns;
-               size_t avail, used;
-               bool idle;
-
-               rq_lock_irqsave(rq, &rf);
-
-               idle = list_empty(&rq->scx.runnable_list) &&
-                       rq->curr->sched_class == &idle_sched_class;
-
-               if (idle && !SCX_HAS_OP(sch, dump_cpu))
-                       goto next;
-
-               /*
-                * We don't yet know whether ops.dump_cpu() will produce output
-                * and we may want to skip the default CPU dump if it doesn't.
-                * Use a nested seq_buf to generate the standard dump so that we
-                * can decide whether to commit later.
-                */
-               avail = seq_buf_get_buf(&s, &buf);
-               seq_buf_init(&ns, buf, avail);
-
-               dump_newline(&ns);
-               dump_line(&ns, "CPU %-4d: nr_run=%u flags=0x%x cpu_rel=%d ops_qseq=%lu ksync=%lu",
-                         cpu, rq->scx.nr_running, rq->scx.flags,
-                         rq->scx.cpu_released, rq->scx.ops_qseq,
-                         rq->scx.kick_sync);
-               dump_line(&ns, "          curr=%s[%d] class=%ps",
-                         rq->curr->comm, rq->curr->pid,
-                         rq->curr->sched_class);
-               if (!cpumask_empty(rq->scx.cpus_to_kick))
-                       dump_line(&ns, "  cpus_to_kick   : %*pb",
-                                 cpumask_pr_args(rq->scx.cpus_to_kick));
-               if (!cpumask_empty(rq->scx.cpus_to_kick_if_idle))
-                       dump_line(&ns, "  idle_to_kick   : %*pb",
-                                 cpumask_pr_args(rq->scx.cpus_to_kick_if_idle));
-               if (!cpumask_empty(rq->scx.cpus_to_preempt))
-                       dump_line(&ns, "  cpus_to_preempt: %*pb",
-                                 cpumask_pr_args(rq->scx.cpus_to_preempt));
-               if (!cpumask_empty(rq->scx.cpus_to_wait))
-                       dump_line(&ns, "  cpus_to_wait   : %*pb",
-                                 cpumask_pr_args(rq->scx.cpus_to_wait));
-               if (!cpumask_empty(rq->scx.cpus_to_sync))
-                       dump_line(&ns, "  cpus_to_sync   : %*pb",
-                                 cpumask_pr_args(rq->scx.cpus_to_sync));
-
-               used = seq_buf_used(&ns);
-               if (SCX_HAS_OP(sch, dump_cpu)) {
-                       ops_dump_init(&ns, "  ");
-                       SCX_CALL_OP(sch, dump_cpu, rq, &dctx, cpu, idle);
-                       ops_dump_exit();
-               }
-
-               /*
-                * If idle && nothing generated by ops.dump_cpu(), there's
-                * nothing interesting. Skip.
-                */
-               if (idle && used == seq_buf_used(&ns))
-                       goto next;
-
-               /*
-                * $s may already have overflowed when $ns was created. If so,
-                * calling commit on it will trigger BUG.
-                */
-               if (avail) {
-                       seq_buf_commit(&s, seq_buf_used(&ns));
-                       if (seq_buf_has_overflowed(&ns))
-                               seq_buf_set_overflow(&s);
-               }
-
-               if (rq->curr->sched_class == &ext_sched_class &&
-                   (dump_all_tasks || scx_task_on_sched(sch, rq->curr)))
-                       scx_dump_task(sch, &s, &dctx, rq, rq->curr, '*');
-
-               list_for_each_entry(p, &rq->scx.runnable_list, scx.runnable_node)
-                       if (dump_all_tasks || scx_task_on_sched(sch, p))
-                               scx_dump_task(sch, &s, &dctx, rq, p, ' ');
-       next:
-               rq_unlock_irqrestore(rq, &rf);
+               scx_dump_cpu(sch, &s, &dctx, cpu, dump_all_tasks);
        }
 
        dump_newline(&s);