[dpdk-dev] [EXT] Re: [PATCH v9 1/5] mempool: populate mempool with the page sized chunks of memory

[Vamsi Krishna Attunuru]

> -----Original Message-----
> From: Andrew Rybchenko <arybchenko at solarflare.com>
> Sent: Monday, July 29, 2019 6:12 PM
> To: Vamsi Krishna Attunuru <vattunuru at marvell.com>; dev at dpdk.org
> Cc: thomas at monjalon.net; Jerin Jacob Kollanukkaran <jerinj at marvell.com>;
> olivier.matz at 6wind.com; ferruh.yigit at intel.com;
> anatoly.burakov at intel.com; Kiran Kumar Kokkilagadda
> <kirankumark at marvell.com>
> Subject: [EXT] Re: [dpdk-dev] [PATCH v9 1/5] mempool: populate mempool
> with the page sized chunks of memory
> 
> External Email
> 
> ----------------------------------------------------------------------
> On 7/29/19 3:13 PM, vattunuru at marvell.com wrote:
> > From: Vamsi Attunuru <vattunuru at marvell.com>
> >
> > Patch adds a routine to populate mempool from page aligned and page
> > sized chunks of memory to ensure memory objs do not fall across the
> > page boundaries. It's useful for applications that require physically
> > contiguous mbuf memory while running in IOVA=VA mode.
> >
> > Signed-off-by: Vamsi Attunuru <vattunuru at marvell.com>
> > Signed-off-by: Kiran Kumar K <kirankumark at marvell.com>
> 
> When two below issues fixed:
> Acked-by: Andrew Rybchenko <arybchenko at solarflare.com>
> 
> As I understand it is likely to be a temporary solution until the problem is
> fixed in a generic way.
> 
> > ---
> >   lib/librte_mempool/rte_mempool.c           | 64
> ++++++++++++++++++++++++++++++
> >   lib/librte_mempool/rte_mempool.h           | 17 ++++++++
> >   lib/librte_mempool/rte_mempool_version.map |  1 +
> >   3 files changed, 82 insertions(+)
> >
> > diff --git a/lib/librte_mempool/rte_mempool.c
> > b/lib/librte_mempool/rte_mempool.c
> > index 7260ce0..00619bd 100644
> > --- a/lib/librte_mempool/rte_mempool.c
> > +++ b/lib/librte_mempool/rte_mempool.c
> > @@ -414,6 +414,70 @@ rte_mempool_populate_virt(struct rte_mempool
> *mp, char *addr,
> >   	return ret;
> >   }
> >
> > +/* Function to populate mempool from page sized mem chunks, allocate
> > +page size
> > + * of memory in memzone and populate them. Return the number of
> > +objects added,
> > + * or a negative value on error.
> > + */
> > +int
> > +rte_mempool_populate_from_pg_sz_chunks(struct rte_mempool *mp) {
> > +	char mz_name[RTE_MEMZONE_NAMESIZE];
> > +	size_t align, pg_sz, pg_shift;
> > +	const struct rte_memzone *mz;
> > +	unsigned int mz_id, n;
> > +	size_t min_chunk_size;
> > +	int ret;
> > +
> > +	ret = mempool_ops_alloc_once(mp);
> > +	if (ret != 0)
> > +		return ret;
> > +
> > +	if (mp->nb_mem_chunks != 0)
> > +		return -EEXIST;
> > +
> > +	pg_sz = get_min_page_size(mp->socket_id);
> > +	pg_shift = rte_bsf32(pg_sz);
> > +
> > +	for (mz_id = 0, n = mp->size; n > 0; mz_id++, n -= ret) {
> > +
> > +		ret = rte_mempool_ops_calc_mem_size(mp, n,
> > +				pg_shift, &min_chunk_size, &align);
> > +
> > +		if (ret < 0 || min_chunk_size > pg_sz)
> 
> If min_chunk_size is greater than pg_sz, ret is 0 and function returns success.

Ack, will fix it in next version.

> 
> > +			goto fail;
> > +
> > +		ret = snprintf(mz_name, sizeof(mz_name),
> > +			RTE_MEMPOOL_MZ_FORMAT "_%d", mp->name,
> mz_id);
> > +		if (ret < 0 || ret >= (int)sizeof(mz_name)) {
> > +			ret = -ENAMETOOLONG;
> > +			goto fail;
> > +		}
> > +
> > +		mz = rte_memzone_reserve_aligned(mz_name,
> min_chunk_size,
> > +				mp->socket_id, 0, align);
> > +
> > +		if (mz == NULL) {
> > +			ret = -rte_errno;
> > +			goto fail;
> > +		}
> > +
> > +		ret = rte_mempool_populate_iova(mp, mz->addr,
> > +				mz->iova, mz->len,
> > +				rte_mempool_memchunk_mz_free,
> > +				(void *)(uintptr_t)mz);
> > +		if (ret < 0) {
> > +			rte_memzone_free(mz);
> > +			goto fail;
> > +		}
> > +	}
> > +
> > +	return mp->size;
> > +
> > +fail:
> > +	rte_mempool_free_memchunks(mp);
> > +	return ret;
> > +}
> > +
> >   /* Default function to populate the mempool: allocate memory in
> memzones,
> >    * and populate them. Return the number of objects added, or a negative
> >    * value on error.
> > diff --git a/lib/librte_mempool/rte_mempool.h
> > b/lib/librte_mempool/rte_mempool.h
> > index 8053f7a..3046e4f 100644
> > --- a/lib/librte_mempool/rte_mempool.h
> > +++ b/lib/librte_mempool/rte_mempool.h
> > @@ -1062,6 +1062,23 @@ rte_mempool_populate_virt(struct
> rte_mempool *mp, char *addr,
> >   	void *opaque);
> >
> >   /**
> 
>   * @warning
>   * @b EXPERIMENTAL: this API may change without prior notice.
> 
> is missing

Ack

> 
> > + * Add memory from page sized memzones for objects in the pool at
> > +init
> > + *
> > + * This is the function used to populate the mempool with page
> > +aligned and
> > + * page sized memzone memory to avoid spreading object memory across
> > +two pages
> > + * and to ensure all mempool objects reside on the page memory.
> > + *
> > + * @param mp
> > + *   A pointer to the mempool structure.
> > + * @return
> > + *   The number of objects added on success.
> > + *   On error, the chunk is not added in the memory list of the
> > + *   mempool and a negative errno is returned.
> > + */
> > +__rte_experimental
> > +int rte_mempool_populate_from_pg_sz_chunks(struct rte_mempool
> *mp);
> > +
> > +/**
> >    * Add memory for objects in the pool at init
> >    *
> >    * This is the default function used by rte_mempool_create() to
> > populate diff --git a/lib/librte_mempool/rte_mempool_version.map
> > b/lib/librte_mempool/rte_mempool_version.map
> > index 17cbca4..9a6fe65 100644
> > --- a/lib/librte_mempool/rte_mempool_version.map
> > +++ b/lib/librte_mempool/rte_mempool_version.map
> > @@ -57,4 +57,5 @@ EXPERIMENTAL {
> >   	global:
> >
> >   	rte_mempool_ops_get_info;
> > +	rte_mempool_populate_from_pg_sz_chunks;
> >   };