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Date: Wed, 5 Jun 2024 21:48:37 -0400
From: Steven Rostedt <rostedt@goodmis.org>
To: Mina Almasry <almasrymina@google.com>
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Subject: Re: [PATCH net-next v10 06/14] page_pool: convert to use netmem
Message-ID: <20240605214837.44efcc6f@gandalf.local.home>
In-Reply-To: <20240530201616.1316526-7-almasrymina@google.com>
References: <20240530201616.1316526-1-almasrymina@google.com>
	<20240530201616.1316526-7-almasrymina@google.com>
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On Thu, 30 May 2024 20:16:05 +0000
Mina Almasry <almasrymina@google.com> wrote:

> @@ -42,51 +42,52 @@ TRACE_EVENT(page_pool_release,
>  TRACE_EVENT(page_pool_state_release,
>  
>  	TP_PROTO(const struct page_pool *pool,
> -		 const struct page *page, u32 release),
> +		 netmem_ref netmem, u32 release),
>  
> -	TP_ARGS(pool, page, release),
> +	TP_ARGS(pool, netmem, release),
>  
>  	TP_STRUCT__entry(
>  		__field(const struct page_pool *,	pool)
> -		__field(const struct page *,		page)
> +		__field(netmem_ref,			netmem)

Why make this of type "netmem_ref" and not just "unsigned long"?

>  		__field(u32,				release)
>  		__field(unsigned long,			pfn)
>  	),
>  
>  	TP_fast_assign(
>  		__entry->pool		= pool;
> -		__entry->page		= page;
> +		__entry->netmem		= netmem;

You could have this be:

		__entry->netmem		= (__force unsigned long)netmem;

>  		__entry->release	= release;
> -		__entry->pfn		= page_to_pfn(page);
> +		__entry->pfn		= netmem_to_pfn(netmem);
>  	),
>  
> -	TP_printk("page_pool=%p page=%p pfn=0x%lx release=%u",
> -		  __entry->pool, __entry->page, __entry->pfn, __entry->release)
> +	TP_printk("page_pool=%p netmem=%lu pfn=0x%lx release=%u",
> +		  __entry->pool, (__force unsigned long)__entry->netmem,

And not have to expose the above text to user space (look at the format
file it produces).

It being of type "netmem_ref" in the ring buffer is useless.

-- Steve


> +		  __entry->pfn, __entry->release)
>  );
>