Re: [dpdk-dev] [PATCH] mbuf: remove inconsistent assert statements

[Adrien Mazarguil <adrien.mazarguil@6wind.com>]

On Wed, Jun 08, 2016 at 10:34:17AM +0000, Ananyev, Konstantin wrote:
> Hi Adrien,
> 
> > 
> > An assertion failure occurs in __rte_mbuf_raw_free() (called by a few PMDs)
> > when compiling DPDK with CONFIG_RTE_LOG_LEVEL=RTE_LOG_DEBUG and starting
> > applications with a log level high enough to trigger it.
> > 
> > While rte_mbuf_raw_alloc() sets refcount to 1, __rte_mbuf_raw_free()
> > expects it to be 0. 
> >Considering users are not expected to reset the
> > reference count to satisfy assert() and that raw functions are designed on
> > purpose without safety belts, remove these checks.
> 
> Yes, it refcnt supposed to be set to 0 by __rte_pktmbuf_prefree_seg().
> Wright now, it is a user responsibility to make sure refcnt==0 before pushing
> mbuf back to the pool.
> Not sure why do you consider that wrong?
> If the user calls __rte_mbuf_raw_free() manualy it is his responsibility to make
> sure mbuf's refcn==0.
> BTW, why are you doing it?
> The comment clearly states that the function is for internal use:
> /**
>  * @internal Put mbuf back into its original mempool.
>  * The use of that function is reserved for RTE internal needs.
>  * Please use rte_pktmbuf_free().
>  *
>  * @param m
>  *   The mbuf to be freed.
>  */
> static inline void __attribute__((always_inline))
> __rte_mbuf_raw_free(struct rte_mbuf *m)

Bottom line is that I'm dropping this patch for now. We'll update our last
mlx5 patchset to do it properly and keep these assert in place.

Thanks.

-- 
Adrien Mazarguil
6WIND