[v4,2/2] mempool/ring: add support for new ring sync modes

Message ID 20200713155050.27743-3-konstantin.ananyev@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series mempool/ring: add support for new ring sync modes |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/travis-robot success Travis build: passed
ci/Intel-compilation success Compilation OK

Commit Message

Ananyev, Konstantin July 13, 2020, 3:50 p.m. UTC
  Two new sync modes were introduced into rte_ring:
relaxed tail sync (RTS) and head/tail sync (HTS).
This change provides user with ability to select these
modes for ring based mempool via mempool ops API.

Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
Acked-by: Gage Eads <gage.eads@intel.com>
---
 doc/guides/mempool/ring.rst             | 10 +++
 doc/guides/rel_notes/release_20_08.rst  |  6 ++
 drivers/mempool/ring/rte_mempool_ring.c | 88 ++++++++++++++++++++++---
 3 files changed, 95 insertions(+), 9 deletions(-)
  

Comments

Thomas Monjalon July 13, 2020, 5:37 p.m. UTC | #1
13/07/2020 17:50, Konstantin Ananyev:
> Two new sync modes were introduced into rte_ring:
> relaxed tail sync (RTS) and head/tail sync (HTS).
> This change provides user with ability to select these
> modes for ring based mempool via mempool ops API.
> 
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> Acked-by: Gage Eads <gage.eads@intel.com>
> ---
>  doc/guides/mempool/ring.rst             | 10 +++
>  doc/guides/rel_notes/release_20_08.rst  |  6 ++
>  drivers/mempool/ring/rte_mempool_ring.c | 88 ++++++++++++++++++++++---
>  3 files changed, 95 insertions(+), 9 deletions(-)
> 
> diff --git a/doc/guides/mempool/ring.rst b/doc/guides/mempool/ring.rst
> index b8659c03f..9e2824070 100644
> --- a/doc/guides/mempool/ring.rst
> +++ b/doc/guides/mempool/ring.rst
> @@ -29,6 +29,16 @@ and can be selected via mempool ops API:
>    Underlying **rte_ring** operates in multi-thread producer,
>    single-thread consumer sync mode.
>  
> +- ``ring_mt_rts``
> +
> +  For underlying **rte_ring** both producer and consumer operate in
> +  multi-thread Relaxed Tail Sync (RTS) mode.
> +
> +- ``ring_mt_hts``
> +
> +  For underlying **rte_ring** both producer and consumer operate in
> +  multi-thread Haad-Tail Sync (HTS) mode.

Typo Haad -> Head

Please explain what these modes mean and why/when use them.
  
Ananyev, Konstantin July 14, 2020, 9:16 a.m. UTC | #2
> 
> 13/07/2020 17:50, Konstantin Ananyev:
> > Two new sync modes were introduced into rte_ring:
> > relaxed tail sync (RTS) and head/tail sync (HTS).
> > This change provides user with ability to select these
> > modes for ring based mempool via mempool ops API.
> >
> > Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > Acked-by: Gage Eads <gage.eads@intel.com>
> > ---
> >  doc/guides/mempool/ring.rst             | 10 +++
> >  doc/guides/rel_notes/release_20_08.rst  |  6 ++
> >  drivers/mempool/ring/rte_mempool_ring.c | 88 ++++++++++++++++++++++---
> >  3 files changed, 95 insertions(+), 9 deletions(-)
> >
> > diff --git a/doc/guides/mempool/ring.rst b/doc/guides/mempool/ring.rst
> > index b8659c03f..9e2824070 100644
> > --- a/doc/guides/mempool/ring.rst
> > +++ b/doc/guides/mempool/ring.rst
> > @@ -29,6 +29,16 @@ and can be selected via mempool ops API:
> >    Underlying **rte_ring** operates in multi-thread producer,
> >    single-thread consumer sync mode.
> >
> > +- ``ring_mt_rts``
> > +
> > +  For underlying **rte_ring** both producer and consumer operate in
> > +  multi-thread Relaxed Tail Sync (RTS) mode.
> > +
> > +- ``ring_mt_hts``
> > +
> > +  For underlying **rte_ring** both producer and consumer operate in
> > +  multi-thread Haad-Tail Sync (HTS) mode.
> 
> Typo Haad -> Head

Will fix.

> 
> Please explain what these modes mean and why/when use them.
> 

We have quite detailed explanation in ring library guide:
https://doc.dpdk.org/guides/prog_guide/ring_lib.html
7.6. Producer/consumer synchronization modes
So here, I put a link to ring library guide for those who need more details.
I can copy&paste same text here too,
but it probably not much point in such duplication.
  
Thomas Monjalon July 15, 2020, 9:59 a.m. UTC | #3
14/07/2020 11:16, Ananyev, Konstantin:
> > 
> > 13/07/2020 17:50, Konstantin Ananyev:
> > > Two new sync modes were introduced into rte_ring:
> > > relaxed tail sync (RTS) and head/tail sync (HTS).
> > > This change provides user with ability to select these
> > > modes for ring based mempool via mempool ops API.
> > >
> > > Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > > Acked-by: Gage Eads <gage.eads@intel.com>
> > > ---
> > > --- a/doc/guides/mempool/ring.rst
> > > +++ b/doc/guides/mempool/ring.rst
> > > @@ -29,6 +29,16 @@ and can be selected via mempool ops API:
> > >    Underlying **rte_ring** operates in multi-thread producer,
> > >    single-thread consumer sync mode.
> > >
> > > +- ``ring_mt_rts``
> > > +
> > > +  For underlying **rte_ring** both producer and consumer operate in
> > > +  multi-thread Relaxed Tail Sync (RTS) mode.
> > > +
> > > +- ``ring_mt_hts``
> > > +
> > > +  For underlying **rte_ring** both producer and consumer operate in
> > > +  multi-thread Haad-Tail Sync (HTS) mode.
> > 
> > Typo Haad -> Head
> 
> Will fix.
> 
> > 
> > Please explain what these modes mean and why/when use them.
> > 
> 
> We have quite detailed explanation in ring library guide:
> https://doc.dpdk.org/guides/prog_guide/ring_lib.html
> 7.6. Producer/consumer synchronization modes
> So here, I put a link to ring library guide for those who need more details.
> I can copy&paste same text here too,
> but it probably not much point in such duplication.

Do not duplicate.
Please add a direct link to the section:
https://doc.dpdk.org/guides/prog_guide/ring_lib.html#mp-rts-mc-rts

From a user perspective, I was looking for recommendation about
which mode is preferred in which case.
Maybe few words about what is an "overcommitted systems"?
  

Patch

diff --git a/doc/guides/mempool/ring.rst b/doc/guides/mempool/ring.rst
index b8659c03f..9e2824070 100644
--- a/doc/guides/mempool/ring.rst
+++ b/doc/guides/mempool/ring.rst
@@ -29,6 +29,16 @@  and can be selected via mempool ops API:
   Underlying **rte_ring** operates in multi-thread producer,
   single-thread consumer sync mode.
 
+- ``ring_mt_rts``
+
+  For underlying **rte_ring** both producer and consumer operate in
+  multi-thread Relaxed Tail Sync (RTS) mode.
+
+- ``ring_mt_hts``
+
+  For underlying **rte_ring** both producer and consumer operate in
+  multi-thread Haad-Tail Sync (HTS) mode.
+
 
 For more information about ``rte_ring`` structure, behaviour and available
 synchronisation modes please refer to: :doc:`../prog_guide/ring_lib`.
diff --git a/doc/guides/rel_notes/release_20_08.rst b/doc/guides/rel_notes/release_20_08.rst
index 17d70e7c1..db25c6f9c 100644
--- a/doc/guides/rel_notes/release_20_08.rst
+++ b/doc/guides/rel_notes/release_20_08.rst
@@ -69,6 +69,12 @@  New Features
   barriers. rte_*mb APIs, for ARMv8 platforms, are changed to use DMB
   instruction to reflect this.
 
+* **Added support for new sync modes into mempool ring driver.**
+
+  Added ability to select new ring synchronisation modes:
+  ``relaxed tail sync (ring_mt_rts)`` and ``head/tail sync (ring_mt_hts)``
+  via mempool ops API.
+
 * **Added the support for vfio-pci new VF token interface.**
 
   From Linux 5.7, vfio-pci supports to bind both SR-IOV PF and the created VFs,
diff --git a/drivers/mempool/ring/rte_mempool_ring.c b/drivers/mempool/ring/rte_mempool_ring.c
index bc123fc52..b1f09ff28 100644
--- a/drivers/mempool/ring/rte_mempool_ring.c
+++ b/drivers/mempool/ring/rte_mempool_ring.c
@@ -25,6 +25,22 @@  common_ring_sp_enqueue(struct rte_mempool *mp, void * const *obj_table,
 			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
 }
 
+static int
+rts_ring_mp_enqueue(struct rte_mempool *mp, void * const *obj_table,
+	unsigned int n)
+{
+	return rte_ring_mp_rts_enqueue_bulk(mp->pool_data,
+			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
+}
+
+static int
+hts_ring_mp_enqueue(struct rte_mempool *mp, void * const *obj_table,
+	unsigned int n)
+{
+	return rte_ring_mp_hts_enqueue_bulk(mp->pool_data,
+			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
+}
+
 static int
 common_ring_mc_dequeue(struct rte_mempool *mp, void **obj_table, unsigned n)
 {
@@ -39,17 +55,30 @@  common_ring_sc_dequeue(struct rte_mempool *mp, void **obj_table, unsigned n)
 			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
 }
 
+static int
+rts_ring_mc_dequeue(struct rte_mempool *mp, void **obj_table, unsigned int n)
+{
+	return rte_ring_mc_rts_dequeue_bulk(mp->pool_data,
+			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
+}
+
+static int
+hts_ring_mc_dequeue(struct rte_mempool *mp, void **obj_table, unsigned int n)
+{
+	return rte_ring_mc_hts_dequeue_bulk(mp->pool_data,
+			obj_table, n, NULL) == 0 ? -ENOBUFS : 0;
+}
+
 static unsigned
 common_ring_get_count(const struct rte_mempool *mp)
 {
 	return rte_ring_count(mp->pool_data);
 }
 
-
 static int
-common_ring_alloc(struct rte_mempool *mp)
+ring_alloc(struct rte_mempool *mp, uint32_t rg_flags)
 {
-	int rg_flags = 0, ret;
+	int ret;
 	char rg_name[RTE_RING_NAMESIZE];
 	struct rte_ring *r;
 
@@ -60,12 +89,6 @@  common_ring_alloc(struct rte_mempool *mp)
 		return -rte_errno;
 	}
 
-	/* ring flags */
-	if (mp->flags & MEMPOOL_F_SP_PUT)
-		rg_flags |= RING_F_SP_ENQ;
-	if (mp->flags & MEMPOOL_F_SC_GET)
-		rg_flags |= RING_F_SC_DEQ;
-
 	/*
 	 * Allocate the ring that will be used to store objects.
 	 * Ring functions will return appropriate errors if we are
@@ -82,6 +105,31 @@  common_ring_alloc(struct rte_mempool *mp)
 	return 0;
 }
 
+static int
+common_ring_alloc(struct rte_mempool *mp)
+{
+	uint32_t rg_flags = 0;
+
+	if (mp->flags & MEMPOOL_F_SP_PUT)
+		rg_flags |= RING_F_SP_ENQ;
+	if (mp->flags & MEMPOOL_F_SC_GET)
+		rg_flags |= RING_F_SC_DEQ;
+
+	return ring_alloc(mp, rg_flags);
+}
+
+static int
+rts_ring_alloc(struct rte_mempool *mp)
+{
+	return ring_alloc(mp, RING_F_MP_RTS_ENQ | RING_F_MC_RTS_DEQ);
+}
+
+static int
+hts_ring_alloc(struct rte_mempool *mp)
+{
+	return ring_alloc(mp, RING_F_MP_HTS_ENQ | RING_F_MC_HTS_DEQ);
+}
+
 static void
 common_ring_free(struct rte_mempool *mp)
 {
@@ -130,7 +178,29 @@  static const struct rte_mempool_ops ops_sp_mc = {
 	.get_count = common_ring_get_count,
 };
 
+/* ops for mempool with ring in MT_RTS sync mode */
+static const struct rte_mempool_ops ops_mt_rts = {
+	.name = "ring_mt_rts",
+	.alloc = rts_ring_alloc,
+	.free = common_ring_free,
+	.enqueue = rts_ring_mp_enqueue,
+	.dequeue = rts_ring_mc_dequeue,
+	.get_count = common_ring_get_count,
+};
+
+/* ops for mempool with ring in MT_HTS sync mode */
+static const struct rte_mempool_ops ops_mt_hts = {
+	.name = "ring_mt_hts",
+	.alloc = hts_ring_alloc,
+	.free = common_ring_free,
+	.enqueue = hts_ring_mp_enqueue,
+	.dequeue = hts_ring_mc_dequeue,
+	.get_count = common_ring_get_count,
+};
+
 MEMPOOL_REGISTER_OPS(ops_mp_mc);
 MEMPOOL_REGISTER_OPS(ops_sp_sc);
 MEMPOOL_REGISTER_OPS(ops_mp_sc);
 MEMPOOL_REGISTER_OPS(ops_sp_mc);
+MEMPOOL_REGISTER_OPS(ops_mt_rts);
+MEMPOOL_REGISTER_OPS(ops_mt_hts);