mempool/ring: support RTS and HTS ring modes

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>
This commit is contained in:
Konstantin Ananyev 2020-07-15 15:58:15 +01:00 committed by David Marchand
parent b7ea4b1635
commit e1187407b4
4 changed files with 113 additions and 11 deletions

View File

@ -12,12 +12,14 @@ and can be selected via mempool ops API:
- ``ring_mp_mc``
The underlying **rte_ring** operates in multi-thread producer,
multi-thread consumer sync mode.
multi-thread consumer sync mode. For more information please refer to:
:ref:`Ring_Library_MPMC_Mode`.
- ``ring_sp_sc``
The underlying **rte_ring** operates in single-thread producer,
single-thread consumer sync mode.
single-thread consumer sync mode. For more information please refer to:
:ref:`Ring_Library_SPSC_Mode`.
- ``ring_sp_mc``
@ -29,6 +31,22 @@ and can be selected via mempool ops API:
The 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. For more information please
refer to: :ref:`Ring_Library_MT_RTS_Mode`.
- ``ring_mt_hts``
For underlying **rte_ring** both producer and consumer operate in
multi-thread Head-Tail Sync (HTS) mode. For more information please
refer to: :ref:`Ring_Library_MT_HTS_Mode`.
For 'classic' DPDK deployments (with one thread per core) the ``ring_mp_mc``
mode is usually the most suitable and the fastest one. For overcommitted
scenarios (multiple threads share same set of cores) the ``ring_mt_rts`` or
``ring_mt_hts`` modes usually provide a better alternative.
For more information about ``rte_ring`` structure, behaviour and available
synchronisation modes please refer to: :doc:`../prog_guide/ring_lib`.

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@ -359,6 +359,8 @@ That should help users to configure ring in the most suitable way for his
specific usage scenarios.
Currently supported modes:
.. _Ring_Library_MPMC_Mode:
MP/MC (default one)
~~~~~~~~~~~~~~~~~~~
@ -369,11 +371,15 @@ per core) this is usually the most suitable and fastest synchronization mode.
As a well known limitation - it can perform quite pure on some overcommitted
scenarios.
.. _Ring_Library_SPSC_Mode:
SP/SC
~~~~~
Single-producer (/single-consumer) mode. In this mode only one thread at a time
is allowed to enqueue (/dequeue) objects to (/from) the ring.
.. _Ring_Library_MT_RTS_Mode:
MP_RTS/MC_RTS
~~~~~~~~~~~~~
@ -390,6 +396,8 @@ one for head update, second for tail update.
In comparison the original MP/MC algorithm requires one 32-bit CAS
for head update and waiting/spinning on tail value.
.. _Ring_Library_MT_HTS_Mode:
MP_HTS/MC_HTS
~~~~~~~~~~~~~

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@ -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 RTS and HTS 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,

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@ -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);