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Date: Fri, 27 Feb 2026 14:46:49 -0500
From: Steven Rostedt <rostedt@goodmis.org>
To: Dmitry Ilvokhin <d@ilvokhin.com>
Cc: Andrew Morton <akpm@linux-foundation.org>, David Hildenbrand
 <david@kernel.org>, Lorenzo Stoakes <lorenzo.stoakes@oracle.com>, "Liam R.
 Howlett" <Liam.Howlett@oracle.com>, Vlastimil Babka <vbabka@suse.cz>, Mike
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 linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org,
 linux-pm@vger.kernel.org, "linux-cxl@vger.kernel.orgkernel-team"@meta.com
Subject: Re: [PATCH v4 5/5] mm: add tracepoints for zone lock
Message-ID: <20260227144649.3dbff742@gandalf.local.home>
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On Fri, 27 Feb 2026 16:00:27 +0000
Dmitry Ilvokhin <d@ilvokhin.com> wrote:

>  static inline void zone_lock_init(struct zone *zone)
>  {
> @@ -12,26 +59,41 @@ static inline void zone_lock_init(struct zone *zone)
>  
>  #define zone_lock_irqsave(zone, flags)				\
>  do {								\
> +	bool success = true;					\
> +								\
> +	__zone_lock_trace_start_locking(zone);			\
>  	spin_lock_irqsave(&(zone)->_lock, flags);		\
> +	__zone_lock_trace_acquire_returned(zone, success);	\

Why the "success" variable and not just:

	__zone_lock_trace_acquire_returned(zone, true);

 ?


>  } while (0)
>  
>  #define zone_trylock_irqsave(zone, flags)			\
>  ({								\
> -	spin_trylock_irqsave(&(zone)->_lock, flags);		\
> +	bool success;						\
> +								\
> +	__zone_lock_trace_start_locking(zone);			\
> +	success = spin_trylock_irqsave(&(zone)->_lock, flags);	\
> +	__zone_lock_trace_acquire_returned(zone, success);	\
> +	success;						\
>  })
>  
>  static inline void zone_unlock_irqrestore(struct zone *zone, unsigned long flags)
>  {
> +	__zone_lock_trace_released(zone);
>  	spin_unlock_irqrestore(&zone->_lock, flags);
>  }
>  
>  static inline void zone_lock_irq(struct zone *zone)
>  {
> +	bool success = true;
> +
> +	__zone_lock_trace_start_locking(zone);
>  	spin_lock_irq(&zone->_lock);
> +	__zone_lock_trace_acquire_returned(zone, success);

Same here.

>  }
>  
>  static inline void zone_unlock_irq(struct zone *zone)
>  {
> +	__zone_lock_trace_released(zone);
>  	spin_unlock_irq(&zone->_lock);
>  }
>

-- Steve