Re: [dpdk-dev] [PATCH v3] ring: add function to free a ring

["De Lara Guarch, Pablo" <pablo.de.lara.guarch@intel.com>]

Hi Bruce,

> -----Original Message-----
> From: Richardson, Bruce
> Sent: Friday, October 02, 2015 3:10 PM
> To: De Lara Guarch, Pablo
> Cc: dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3] ring: add function to free a ring
> 
> On Fri, Oct 02, 2015 at 03:01:25PM +0100, Pablo de Lara wrote:
> > From: "Pablo de Lara" <pablo.de.lara.guarch@intel.com>
> >
> > When creating a ring, a memzone is created to allocate it in memory,
> > but the ring could not be freed, as memzones could not be.
> >
> > Since memzones can be freed now, then rings can be as well,
> > taking into account if they were initialized using pre-allocated memory
> > (in which case, memory should be freed externally) or using
> rte_memzone_reserve
> > (with rte_ring_create), freeing the memory with rte_memzone_free.
> >
> > Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
> > ---
> > Changes in v3:
> >  - Simplify patch using stored memzone address in ring structure
> >  - Change copyright date
> 
> I think you need to call out that this patch depends upon
> http://dpdk.org/dev/patchwork/patch/7308/

I did below, probably I should have included the patch ID :S

> 
> >
> > Changes in v2:
> >  - Include note in release notes
> >  - Add error log when ring cannot be freed
> >
> > This patch depends on patch "rte_ring: store memzone pointer inside ring"
> >
> >  doc/guides/rel_notes/release_2_2.rst |  4 +++
> >  lib/librte_ring/rte_ring.c           | 47
> +++++++++++++++++++++++++++++++++++-
> >  lib/librte_ring/rte_ring.h           |  7 ++++++
> >  lib/librte_ring/rte_ring_version.map |  7 ++++++
> >  4 files changed, 64 insertions(+), 1 deletion(-)
> >
> > diff --git a/doc/guides/rel_notes/release_2_2.rst
> b/doc/guides/rel_notes/release_2_2.rst
> > index 5687676..24937ac 100644
> > --- a/doc/guides/rel_notes/release_2_2.rst
> > +++ b/doc/guides/rel_notes/release_2_2.rst
> > @@ -4,6 +4,10 @@ DPDK Release 2.2
> >  New Features
> >  ------------
> >
> > +* **Enabled freeing of rte_ring.**
> > +
> > +  New function rte_ring_free() allows the user to free a ring
> > +  if it was created with rte_ring_create().
> >
> >  Resolved Issues
> >  ---------------
> > diff --git a/lib/librte_ring/rte_ring.c b/lib/librte_ring/rte_ring.c
> > index 4e78e14..d80faf3 100644
> > --- a/lib/librte_ring/rte_ring.c
> > +++ b/lib/librte_ring/rte_ring.c
> > @@ -1,7 +1,7 @@
> >  /*-
> >   *   BSD LICENSE
> >   *
> > - *   Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
> > + *   Copyright(c) 2010-2015 Intel Corporation. All rights reserved.
> >   *   All rights reserved.
> >   *
> >   *   Redistribution and use in source and binary forms, with or without
> > @@ -209,6 +209,51 @@ rte_ring_create(const char *name, unsigned
> count, int socket_id,
> >  	return r;
> >  }
> >
> > +/* free the ring */
> > +void
> > +rte_ring_free(struct rte_ring *r)
> > +{
> > +	struct rte_ring_list *ring_list = NULL;
> > +	struct rte_tailq_entry *te;
> > +
> > +	if (r == NULL)
> > +		return;
> > +
> > +	/*
> > +	 * Ring was not created with rte_ring_create,
> > +	 * therefore, there is no memzone to free.
> > +	 */
> > +	if (r->memzone == NULL) {
> > +		RTE_LOG(ERR, RING, "Cannot free ring (not created with
> rte_ring_create()");
> > +		return;
> > +	}
> > +
> > +	if (rte_memzone_free(r->memzone) != 0) {
> > +		RTE_LOG(ERR, RING, "Cannot free memory\n");
> > +		return;
> > +	}
> > +
> > +	ring_list = RTE_TAILQ_CAST(rte_ring_tailq.head, rte_ring_list);
> > +	rte_rwlock_write_lock(RTE_EAL_TAILQ_RWLOCK);
> > +
> > +	/* find out tailq entry */
> > +	TAILQ_FOREACH(te, ring_list, next) {
> > +		if (te->data == (void *) r)
> > +			break;
> > +	}
> > +
> > +	if (te == NULL) {
> > +		rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
> > +		return;
> > +	}
> > +
> > +	TAILQ_REMOVE(ring_list, te, next);
> > +
> > +	rte_rwlock_write_unlock(RTE_EAL_TAILQ_RWLOCK);
> > +
> > +	rte_free(te);
> > +}
> > +
> >  /*
> >   * change the high water mark. If *count* is 0, water marking is
> >   * disabled
> > diff --git a/lib/librte_ring/rte_ring.h b/lib/librte_ring/rte_ring.h
> > index df45f3f..fb5a626 100644
> > --- a/lib/librte_ring/rte_ring.h
> > +++ b/lib/librte_ring/rte_ring.h
> > @@ -304,6 +304,13 @@ int rte_ring_init(struct rte_ring *r, const char
> *name, unsigned count,
> >   */
> >  struct rte_ring *rte_ring_create(const char *name, unsigned count,
> >  				 int socket_id, unsigned flags);
> > +/**
> > + * De-allocate all memory used by the ring.
> > + *
> > + * @param r
> > + *   Ring to free
> > + */
> > +void rte_ring_free(struct rte_ring *r);
> >
> >  /**
> >   * Change the high water mark.
> > diff --git a/lib/librte_ring/rte_ring_version.map
> b/lib/librte_ring/rte_ring_version.map
> > index 982fdd1..5474b98 100644
> > --- a/lib/librte_ring/rte_ring_version.map
> > +++ b/lib/librte_ring/rte_ring_version.map
> > @@ -11,3 +11,10 @@ DPDK_2.0 {
> >
> >  	local: *;
> >  };
> > +
> > +DPDK_2.2 {
> > +	global:
> > +
> > +	rte_ring_free;
> > +
> > +} DPDK_2.0;
> > --
> > 2.4.3
> >