[PATCH v2 sched_ext/for-6.18] sched_ext: Add migration-disabled counter to error state dump

[PATCH v2 sched_ext/for-6.18] sched_ext: Add migration-disabled counter to error state dump

[Andrea Righi]

Include the task's migration-disabled counter when dumping task state
during an error exit.

This can help diagnose cases where tasks can get stuck, because they're
unable to migrate elsewhere.

Signed-off-by: Andrea Righi <arighi@nvidia.com>
---
Changes in v2:
 - Abbreviate migration_disabled= to nomig= (Tejun)
 - Link to v1: https://lore.kernel.org/all/20250918092928.402242-1-arighi@nvidia.com/

 kernel/sched/ext.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/sched/ext.c b/kernel/sched/ext.c
index 4e6d83b3b7775..d33e6edef65c8 100644
--- a/kernel/sched/ext.c
+++ b/kernel/sched/ext.c
@@ -4266,7 +4266,8 @@ static void scx_dump_task(struct seq_buf *s, struct scx_dump_ctx *dctx,
 		  p->scx.sticky_cpu, p->scx.holding_cpu, dsq_id_buf);
 	dump_line(s, "      dsq_vtime=%llu slice=%llu weight=%u",
 		  p->scx.dsq_vtime, p->scx.slice, p->scx.weight);
-	dump_line(s, "      cpus=%*pb", cpumask_pr_args(p->cpus_ptr));
+	dump_line(s, "      cpus=%*pb nomig=%u", cpumask_pr_args(p->cpus_ptr),
+		  p->migration_disabled);
 
 	if (SCX_HAS_OP(sch, dump_task)) {
 		ops_dump_init(s, "    ");
-- 
2.51.0

Re: [PATCH v2 sched_ext/for-6.18] sched_ext: Add migration-disabled counter to error state dump

[Tejun Heo]

On Thu, Sep 18, 2025 at 07:06:02PM +0200, Andrea Righi wrote:
> Include the task's migration-disabled counter when dumping task state
> during an error exit.
> 
> This can help diagnose cases where tasks can get stuck, because they're
> unable to migrate elsewhere.
> 
> Signed-off-by: Andrea Righi <arighi@nvidia.com>

I did s/nomig/no_mig/ for a bit better readability and because other keys
are using _ as word separators (e.g. dsq_id).

Applied to sched_ext/for-6.18.

Thanks.

-- 
tejun

Re: [PATCH v2 sched_ext/for-6.18] sched_ext: Add migration-disabled counter to error state dump

[Andrea Righi]

On Thu, Sep 18, 2025 at 08:57:06AM -1000, Tejun Heo wrote:
> On Thu, Sep 18, 2025 at 07:06:02PM +0200, Andrea Righi wrote:
> > Include the task's migration-disabled counter when dumping task state
> > during an error exit.
> > 
> > This can help diagnose cases where tasks can get stuck, because they're
> > unable to migrate elsewhere.
> > 
> > Signed-off-by: Andrea Righi <arighi@nvidia.com>
> 
> I did s/nomig/no_mig/ for a bit better readability and because other keys
> are using _ as word separators (e.g. dsq_id).

Ack, looks good to me.

Thanks!
-Andrea