Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 303abfdf authored by Dennis Zhou's avatar Dennis Zhou Committed by Tejun Heo
Browse files

percpu: fix early calls for spinlock in pcpu_stats 



From 2c06e795162cb306c9707ec51d3e1deadb37f573 Mon Sep 17 00:00:00 2001
From: Dennis Zhou <dennisz@fb.com>
Date: Wed, 21 Jun 2017 10:17:09 -0700

Commit 30a5b536 ("percpu: expose statistics about percpu memory via
debugfs") introduces percpu memory statistics. pcpu_stats_chunk_alloc
takes the spin lock and disables/enables irqs on creation of a chunk. Irqs
are not enabled when the first chunk is initialized and thus kernels are
failing to boot with kernel debugging enabled. Fixed by changing _irq to
_irqsave and _irqrestore.

Fixes: 30a5b536 ("percpu: expose statistics about percpu memory via debugfs")
Signed-off-by: default avatarDennis Zhou <dennisz@fb.com>
Reported-by: default avatarAlexander Levin <alexander.levin@verizon.com>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent 11df02bf

mm/percpu-internal.h

+6 −4
Original line number Diff line number Diff line
@@ -116,13 +116,14 @@ static inline void pcpu_stats_area_dealloc(struct pcpu_chunk *chunk) 
 */

static inline void pcpu_stats_chunk_alloc(void)

{

	spin_lock_irq(&pcpu_lock);

	unsigned long flags;

	spin_lock_irqsave(&pcpu_lock, flags);



	pcpu_stats.nr_chunks++;

	pcpu_stats.nr_max_chunks =

		max(pcpu_stats.nr_max_chunks, pcpu_stats.nr_chunks);



	spin_unlock_irq(&pcpu_lock);

	spin_unlock_irqrestore(&pcpu_lock, flags);

}



/*
@@ -130,11 +131,12 @@ static inline void pcpu_stats_chunk_alloc(void) 
 */

static inline void pcpu_stats_chunk_dealloc(void)

{

	spin_lock_irq(&pcpu_lock);

	unsigned long flags;

	spin_lock_irqsave(&pcpu_lock, flags);



	pcpu_stats.nr_chunks--;



	spin_unlock_irq(&pcpu_lock);

	spin_unlock_irqrestore(&pcpu_lock, flags);

}



#else