[dpdk-dev] [PATCH v2] mbuf: enforce alignment of mbuf private area

[Ananyev, Konstantin]

> -----Original Message-----
> From: Olivier Matz [mailto:olivier.matz at 6wind.com]
> Sent: Thursday, July 30, 2015 5:22 PM
> To: dev at dpdk.org
> Cc: Ananyev, Konstantin; olivier.matz at 6wind.com; Zhang, Helin; martin.weiser at allegro-packets.com; thomas.monjalon at 6wind.com
> Subject: [PATCH v2] mbuf: enforce alignment of mbuf private area
> 
> It looks better to have a data buffer address that is aligned to
> 8 bytes. This is the case when there is no mbuf private area, but
> if there is one, the alignment depends on the size of this area
> that is located between the mbuf structure and the data buffer.
> 
> Indeed, some drivers expects to have the buffer address aligned
> to an even address, and moreover an unaligned buffer may impact
> the performance when accessing to network headers.
> 
> Add a check in rte_pktmbuf_pool_create() to verify the alignment
> constraint before creating the mempool. For applications that use
> the alternative way (direct call to rte_mempool_create), also
> add an assertion in rte_pktmbuf_init().
> 
> By the way, also add the MBUF log type.
> 
> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> ---

Acked-by: Konstantin Ananyev <konstantin.ananyev at intel.com>