Re: [dpdk-dev] [PATCH v3] mbuf: minor cleanup

[Thomas Monjalon <thomas@monjalon.net>]

Hi Morten,
Any update about this patch please?

07/10/2020 11:16, Olivier Matz:
> Hi Morten,
> 
> Thanks for this cleanup. Please see some comments below.
> 
> On Wed, Sep 16, 2020 at 12:40:13PM +0200, Morten Brørup wrote:
> > The mbuf header files had some commenting style errors that affected the
> > API documentation.
> > Also, the RTE_ prefix was missing on a macro and a definition.
> > 
> > Note: This patch does not touch the offload and attachment flags that are
> > also missing the RTE_ prefix.
> > 
> > Changes only affecting documentation:
> > * Removed the MBUF_INVALID_PORT definition from rte_mbuf.h; it is
> >   already defined in rte_mbuf_core.h.
> >   This removal also reestablished the description of the
> >   rte_pktmbuf_reset() function.
> > * Corrected the comment related to RTE_MBUF_MAX_NB_SEGS.
> > * Corrected the comment related to PKT_TX_QINQ_PKT.
> > 
> > Changes regarding missing RTE_ prefix:
> > * Converted the MBUF_RAW_ALLOC_CHECK() macro to an
> >   __rte_mbuf_raw_sanity_check() inline function.
> >   Added backwards compatible macro with the original name.
> > * Renamed the MBUF_INVALID_PORT definition to RTE_MBUF_PORT_INVALID.
> >   Added backwards compatible definition with the original name.
> > 
> > v2:
> > * Use RTE_MBUF_PORT_INVALID instead of MBUF_INVALID_PORT in rte_mbuf.c.
> > 
> > v3:
> > * The functions/macros used in __rte_mbuf_raw_sanity_check() require
> >   RTE_ENABLE_ASSERT or RTE_LIBRTE_MBUF_DEBUG, or they don't use the mbuf
> >   parameter, which generates a compiler waning. So mark the mbuf parameter
> >   __rte_unused if none of them are defined.
> > 
> > Signed-off-by: Morten Brørup <mb@smartsharesystems.com>
> > ---
> >  doc/guides/rel_notes/deprecation.rst |  7 ----
> >  lib/librte_mbuf/rte_mbuf.c           |  4 +-
> >  lib/librte_mbuf/rte_mbuf.h           | 55 +++++++++++++++++++---------
> >  lib/librte_mbuf/rte_mbuf_core.h      |  9 +++--
> >  4 files changed, 45 insertions(+), 30 deletions(-)
> > 
> > diff --git a/doc/guides/rel_notes/deprecation.rst b/doc/guides/rel_notes/deprecation.rst
> > index 279eccb04..88d7d0761 100644
> > --- a/doc/guides/rel_notes/deprecation.rst
> > +++ b/doc/guides/rel_notes/deprecation.rst
> > @@ -294,13 +294,6 @@ Deprecation Notices
> >    - https://patches.dpdk.org/patch/71457/
> >    - https://patches.dpdk.org/patch/71456/
> >  
> > -* rawdev: The rawdev APIs which take a device-specific structure as
> > -  parameter directly, or indirectly via a "private" pointer inside another
> > -  structure, will be modified to take an additional parameter of the
> > -  structure size. The affected APIs will include ``rte_rawdev_info_get``,
> > -  ``rte_rawdev_configure``, ``rte_rawdev_queue_conf_get`` and
> > -  ``rte_rawdev_queue_setup``.
> > -
> >  * acl: ``RTE_ACL_CLASSIFY_NUM`` enum value will be removed.
> >    This enum value is not used inside DPDK, while it prevents to add new
> >    classify algorithms without causing an ABI breakage.
> 
> I think this change is not related.
> 
> This makes me think that a deprecation notice could be done for the
> old names without the RTE_ prefix, to be removed in 21.11.
> 
> 
> > diff --git a/lib/librte_mbuf/rte_mbuf.c b/lib/librte_mbuf/rte_mbuf.c
> > index 8a456e5e6..53a015311 100644
> > --- a/lib/librte_mbuf/rte_mbuf.c
> > +++ b/lib/librte_mbuf/rte_mbuf.c
> > @@ -104,7 +104,7 @@ rte_pktmbuf_init(struct rte_mempool *mp,
> >  	/* init some constant fields */
> >  	m->pool = mp;
> >  	m->nb_segs = 1;
> > -	m->port = MBUF_INVALID_PORT;
> > +	m->port = RTE_MBUF_PORT_INVALID;
> >  	rte_mbuf_refcnt_set(m, 1);
> >  	m->next = NULL;
> >  }
> > @@ -207,7 +207,7 @@ __rte_pktmbuf_init_extmem(struct rte_mempool *mp,
> >  	/* init some constant fields */
> >  	m->pool = mp;
> >  	m->nb_segs = 1;
> > -	m->port = MBUF_INVALID_PORT;
> > +	m->port = RTE_MBUF_PORT_INVALID;
> >  	m->ol_flags = EXT_ATTACHED_MBUF;
> >  	rte_mbuf_refcnt_set(m, 1);
> >  	m->next = NULL;
> > diff --git a/lib/librte_mbuf/rte_mbuf.h b/lib/librte_mbuf/rte_mbuf.h
> > index 7259575a7..406d3abb2 100644
> > --- a/lib/librte_mbuf/rte_mbuf.h
> > +++ b/lib/librte_mbuf/rte_mbuf.h
> > @@ -554,12 +554,36 @@ __rte_experimental
> >  int rte_mbuf_check(const struct rte_mbuf *m, int is_header,
> >  		   const char **reason);
> >  
> > -#define MBUF_RAW_ALLOC_CHECK(m) do {				\
> > -	RTE_ASSERT(rte_mbuf_refcnt_read(m) == 1);		\
> > -	RTE_ASSERT((m)->next == NULL);				\
> > -	RTE_ASSERT((m)->nb_segs == 1);				\
> > -	__rte_mbuf_sanity_check(m, 0);				\
> > -} while (0)
> > +#if defined(RTE_ENABLE_ASSERT) || defined(RTE_LIBRTE_MBUF_DEBUG)
> 
> I don't see why this #if is needed. Wouldn't it work to have only
> one function definition with the __rte_unused attribute?
> 
> > +/**
> > + * Sanity checks on a reinitialized mbuf.
> > + *
> > + * Check the consistency of the given reinitialized mbuf.
> > + * The function will cause a panic if corruption is detected.
> > + *
> > + * Check that the mbuf is properly reinitialized (refcnt=1, next=NULL,
> > + * nb_segs=1), as done by rte_pktmbuf_prefree_seg().
> > + *
> 
> Maybe indicate that these checks are only done when debug is on.
> 
> > + * @param m
> > + *   The mbuf to be checked.
> > + */
> > +static __rte_always_inline void
> > +__rte_mbuf_raw_sanity_check(const struct rte_mbuf *m)
> > +{
> > +	RTE_ASSERT(rte_mbuf_refcnt_read(m) == 1);
> > +	RTE_ASSERT(m->next == NULL);
> > +	RTE_ASSERT(m->nb_segs == 1);
> > +	__rte_mbuf_sanity_check(m, 0);
> > +}
> > +#else
> > +static __rte_always_inline void
> > +__rte_mbuf_raw_sanity_check(const struct rte_mbuf *m __rte_unused)
> > +{
> > +    /* Nothing here. */
> > +}
> > +#endif
> > +/** For backwards compatibility. */
> > +#define MBUF_RAW_ALLOC_CHECK(m) __rte_mbuf_raw_sanity_check(m)
> 
> It looks that MBUF_RAW_ALLOC_CHECK() is also used in drivers/net/sfc,
> I think it should be updated too.
> 
> >  
> >  /**
> >   * Allocate an uninitialized mbuf from mempool *mp*.
> > @@ -586,7 +610,7 @@ static inline struct rte_mbuf *rte_mbuf_raw_alloc(struct rte_mempool *mp)
> >  
> >  	if (rte_mempool_get(mp, (void **)&m) < 0)
> >  		return NULL;
> > -	MBUF_RAW_ALLOC_CHECK(m);
> > +	__rte_mbuf_raw_sanity_check(m);
> >  	return m;
> >  }
> >  
> > @@ -609,10 +633,7 @@ rte_mbuf_raw_free(struct rte_mbuf *m)
> >  {
> >  	RTE_ASSERT(!RTE_MBUF_CLONED(m) &&
> >  		  (!RTE_MBUF_HAS_EXTBUF(m) || RTE_MBUF_HAS_PINNED_EXTBUF(m)));
> > -	RTE_ASSERT(rte_mbuf_refcnt_read(m) == 1);
> > -	RTE_ASSERT(m->next == NULL);
> > -	RTE_ASSERT(m->nb_segs == 1);
> > -	__rte_mbuf_sanity_check(m, 0);
> > +	__rte_mbuf_raw_sanity_check(m);
> >  	rte_mempool_put(m->pool, m);
> >  }
> >  
> > @@ -858,8 +879,6 @@ static inline void rte_pktmbuf_reset_headroom(struct rte_mbuf *m)
> >   * @param m
> >   *   The packet mbuf to be reset.
> >   */
> > -#define MBUF_INVALID_PORT UINT16_MAX
> > -
> >  static inline void rte_pktmbuf_reset(struct rte_mbuf *m)
> >  {
> >  	m->next = NULL;
> > @@ -868,7 +887,7 @@ static inline void rte_pktmbuf_reset(struct rte_mbuf *m)
> >  	m->vlan_tci = 0;
> >  	m->vlan_tci_outer = 0;
> >  	m->nb_segs = 1;
> > -	m->port = MBUF_INVALID_PORT;
> > +	m->port = RTE_MBUF_PORT_INVALID;
> >  
> >  	m->ol_flags &= EXT_ATTACHED_MBUF;
> >  	m->packet_type = 0;
> > @@ -931,22 +950,22 @@ static inline int rte_pktmbuf_alloc_bulk(struct rte_mempool *pool,
> >  	switch (count % 4) {
> >  	case 0:
> >  		while (idx != count) {
> > -			MBUF_RAW_ALLOC_CHECK(mbufs[idx]);
> > +			__rte_mbuf_raw_sanity_check(mbufs[idx]);
> >  			rte_pktmbuf_reset(mbufs[idx]);
> >  			idx++;
> >  			/* fall-through */
> >  	case 3:
> > -			MBUF_RAW_ALLOC_CHECK(mbufs[idx]);
> > +			__rte_mbuf_raw_sanity_check(mbufs[idx]);
> >  			rte_pktmbuf_reset(mbufs[idx]);
> >  			idx++;
> >  			/* fall-through */
> >  	case 2:
> > -			MBUF_RAW_ALLOC_CHECK(mbufs[idx]);
> > +			__rte_mbuf_raw_sanity_check(mbufs[idx]);
> >  			rte_pktmbuf_reset(mbufs[idx]);
> >  			idx++;
> >  			/* fall-through */
> >  	case 1:
> > -			MBUF_RAW_ALLOC_CHECK(mbufs[idx]);
> > +			__rte_mbuf_raw_sanity_check(mbufs[idx]);
> >  			rte_pktmbuf_reset(mbufs[idx]);
> >  			idx++;
> >  			/* fall-through */
> > diff --git a/lib/librte_mbuf/rte_mbuf_core.h b/lib/librte_mbuf/rte_mbuf_core.h
> > index 8cd7137ac..4ac5609e3 100644
> > --- a/lib/librte_mbuf/rte_mbuf_core.h
> > +++ b/lib/librte_mbuf/rte_mbuf_core.h
> > @@ -272,7 +272,7 @@ extern "C" {
> >   * mbuf 'vlan_tci' & 'vlan_tci_outer' must be valid when this flag is set.
> >   */
> >  #define PKT_TX_QINQ        (1ULL << 49)
> > -/* this old name is deprecated */
> > +/** This old name is deprecated. */
> >  #define PKT_TX_QINQ_PKT    PKT_TX_QINQ
> >  
> >  /**
> > @@ -686,7 +686,7 @@ struct rte_mbuf_ext_shared_info {
> >  	};
> >  };
> >  
> > -/**< Maximum number of nb_segs allowed. */
> > +/** Maximum number of nb_segs allowed. */
> >  #define RTE_MBUF_MAX_NB_SEGS	UINT16_MAX
> >  
> >  /**
> > @@ -714,7 +714,10 @@ struct rte_mbuf_ext_shared_info {
> >  #define RTE_MBUF_DIRECT(mb) \
> >  	(!((mb)->ol_flags & (IND_ATTACHED_MBUF | EXT_ATTACHED_MBUF)))
> >  
> > -#define MBUF_INVALID_PORT UINT16_MAX
> > +/** NULL value for the uint16_t port type. */
> > +#define RTE_MBUF_PORT_INVALID UINT16_MAX
> 
> I don't really like talking about "NULL". What do you think instead of
> this wording?
> 
>   /** Uninitialized or unspecified port */
> 
> > +/** For backwards compatibility. */
> > +#define MBUF_INVALID_PORT RTE_MBUF_PORT_INVALID
> >  
> >  /**
> >   * A macro that points to an offset into the data in the mbuf.
> 
> Thanks,
> Olivier
>