Commit eff782fd authored by Tejun Heo's avatar Tejun Heo
Browse files

sched_ext: Convert scx_dump_state() spinlock to raw spinlock 



The scx_dump_state() function uses a regular spinlock to serialize
access. In a subsequent patch, this function will be called while
holding scx_sched_lock, which is a raw spinlock, creating a lock
nesting violation.

Convert the dump_lock to a raw spinlock and use the guard macro for
cleaner lock management.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Reviewed-by: default avatarAndrea Righi <arighi@nvidia.com>
parent cde94c03

kernel/sched/ext.c

+2 −5
Original line number Diff line number Diff line
@@ -5220,7 +5220,7 @@ static void scx_dump_task(struct seq_buf *s, struct scx_dump_ctx *dctx, 


static void scx_dump_state(struct scx_exit_info *ei, size_t dump_len)

{

	static DEFINE_SPINLOCK(dump_lock);

	static DEFINE_RAW_SPINLOCK(dump_lock);

	static const char trunc_marker[] = "\n\n~~~~ TRUNCATED ~~~~\n";

	struct scx_sched *sch = scx_root;

	struct scx_dump_ctx dctx = {
@@ -5232,11 +5232,10 @@ static void scx_dump_state(struct scx_exit_info *ei, size_t dump_len) 
	};

	struct seq_buf s;

	struct scx_event_stats events;

	unsigned long flags;

	char *buf;

	int cpu;



	spin_lock_irqsave(&dump_lock, flags);

	guard(raw_spinlock_irqsave)(&dump_lock);



	seq_buf_init(&s, ei->dump, dump_len);
@@ -5361,8 +5360,6 @@ static void scx_dump_state(struct scx_exit_info *ei, size_t dump_len) 
	if (seq_buf_has_overflowed(&s) && dump_len >= sizeof(trunc_marker))

		memcpy(ei->dump + dump_len - sizeof(trunc_marker),

		       trunc_marker, sizeof(trunc_marker));



	spin_unlock_irqrestore(&dump_lock, flags);

}



static void scx_error_irq_workfn(struct irq_work *irq_work)