Re: [PATCH v2] mm/page_alloc: trace PCP refills and PCP zone lock usage

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 27 Apr 2026 14:01:42 +0800
Bunyod Suvonov <b.suvonov@sjtu.edu.cn> wrote:

> +	TP_STRUCT__entry(
> +		__field(int, nid)
> +		__field(int, zid)
> +		__field(unsigned long, nr_pages)
> +	),
> +
> +	TP_fast_assign(
> +		__entry->nid		= nid;
> +		__entry->zid		= zid;
> +		__entry->nr_pages	= nr_pages;
> +	),
> +
> +	TP_printk("nid=%d zid=%d nr_pages=%lu",
> +		__entry->nid, __entry->zid, __entry->nr_pages)
> +);
> +
> +DEFINE_EVENT(mm_page_pcpu_zone_locked, mm_page_pcpu_refill_zone_locked,
> +
> +	TP_PROTO(int nid, int zid, unsigned long nr_pages),
> +
> +	TP_ARGS(nid, zid, nr_pages)
> +);
> +
> +DEFINE_EVENT(mm_page_pcpu_zone_locked, mm_page_pcpu_drain_zone_locked,
> +
> +	TP_PROTO(int nid, int zid, unsigned long nr_pages),
> +
> +	TP_ARGS(nid, zid, nr_pages)
> +);
> +
> +DECLARE_EVENT_CLASS(mm_page_pcpu,
>  
>  	TP_PROTO(struct page *page, unsigned int order, int migratetype),
>  
>  	TP_ARGS(page, order, migratetype),
>  
>  	TP_STRUCT__entry(
> -		__field(	unsigned long,	pfn		)
> -		__field(	unsigned int,	order		)
> -		__field(	int,		migratetype	)
> +		__field(unsigned long, pfn)
> +		__field(unsigned int, order)
> +		__field(int, migratetype)

Why this change? It makes it much harder to understand.

The above is not a normal macro. Ignore any checkpatch warnings about it.
The proper way to do the TP_STRUCT__entry() is to make it just like a struct:

struct {
	unsigned long		pfn;
	unsigned int		order;
	int			migratetype;
};

Thus, the macro should be:

	TP_STRUCT__entry(
		__field(	unsigned long,	pfn		)
		__field(	unsigned int,	order		)
		__field(	int,		migratetype	)
	),

-- Steve



>  	),
>