Re: [PATCH net-next v10 06/14] page_pool: convert to use netmem

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)
  

);