Hi Hemant,
On Thursday 07 September 2017 02:51 PM, Hemant Agrawal wrote: > On 9/4/2017 6:44 PM, santosh wrote: >> Hi Olivier, >> >> >> On Monday 04 September 2017 05:41 PM, Olivier MATZ wrote: >>> Hi Santosh, >>> >>> On Tue, Aug 15, 2017 at 01:37:17PM +0530, Santosh Shukla wrote: >>>> Now that dpdk supports more than one mempool drivers and >>>> each mempool driver works best for specific PMD, example: >>>> - sw ring based mempool for Intel PMD drivers >>>> - dpaa2 HW mempool manager for dpaa2 PMD driver. >>>> - fpa HW mempool manager for Octeontx PMD driver. >>>> >>>> Application like to know `preferred mempool vs PMD driver` >>>> information in advance before port setup. >>>> >>>> Introducing rte_eth_dev_get_preferred_pool_ops() API, >>>> which allows PMD driver to advertise their pool capability to application. >>>> >>>> Application side programing sequence would be: >>>> >>>> char pref_mempool[RTE_MEMPOOL_OPS_NAMESIZE]; >>>> rte_eth_dev_get_preferred_pool_ops(ethdev_port_id, pref_mempoolx /*out*/); >>>> rte_mempool_create_empty(); >>>> rte_mempool_set_ops_byname( , pref_memppol, ); >>>> rte_mempool_populate_default(); >>>> >>>> Signed-off-by: Santosh Shukla <santosh.shu...@caviumnetworks.com> >>>> --- >>>> v2 --> v3: >>>> - Updated version.map entry to DPDK_v17.11. >>>> >>>> v1 --> v2: >>>> - Renamed _get_preferred_pool to _get_preferred_pool_ops(). >>>> Per v1 review feedback, Olivier suggested to rename api >>>> to rte_eth_dev_pool_ops_supported(), considering that 2nd param >>>> for that api will return pool handle 'priority' for that port. >>>> However, per v1 [1], we're opting for approach 1) where >>>> ethdev API returns _preferred_ pool handle to application and Its upto >>>> application to decide on policy - whether application wants to create >>>> pool with received preferred pool handle or not. For more discussion >>>> details >>>> on this topic refer [1]. >>> Well, I still think it would be more flexible to have an API like >>> rte_eth_dev_pool_ops_supported(uint8_t port_id, const char *pool) >>> >>> It supports the easy case (= one preferred mempool) without much pain, >>> and provides a more precise manner to describe what is supported or not >>> by the driver. Example: "pmd_foo" prefers "mempool_foo" (best perf), but >>> also supporst "mempool_stack" and "mempool_ring", but "mempool_bar" >>> won't work at all. >>> >>> Having only one preferred pool_ops also prevents from smoothly renaming >>> a pool (supporting both during some time) or to have 2 names for >>> different variants of the same pool_ops (ex: ring_mp_mc, ring_sp_sc). >>> >>> But if the users (I guess at least Cavium and NXP) are happy with >>> what you propose, I'm fine with it. >> >> preferred handle based upon real world use-case and same thing raised >> at [1]. >> >> Hi Hemant, Are you ok with proposed preferred API? >> >> [1] http://dpdk.org/dev/patchwork/patch/24944/ >> > > The current patch is ok, but it is better if you can extend it to provide > list of preferred pools (in preference order) instead of just one pool. This > will become helpful. I will avoid providing list of not-supported pools etc. > > A driver can have more than one preferred pool, depend on the resource > availability one or other can be used. I am also proposing this in my > proposal[1]. > > [1] http://dpdk.org/dev/patchwork/patch/26377/ > Ok, then sticking to Olivier api but slight change in param, example: /** * Get list of supported pools for a port * * @param port_id [in] * Pointer to port identifier of the device. * @param pools [out] * Pointer to the list of supported pools for that port. * Returns with array of pool ops name handler of size * RTE_MEMPOOL_OPS_NAMESIZE. * @return * >=0: Success; PMD has updated supported pool list. * <0: Failure; */ int rte_eth_dev_pools_ops_supported(uint8_t port_id, char **pools) Hemant, Olivier: Does above api make sense? Pl. confirm. Thanks. > > >>>> --- a/lib/librte_ether/rte_ethdev.c >>>> +++ b/lib/librte_ether/rte_ethdev.c >>>> @@ -3409,3 +3409,21 @@ rte_eth_dev_adjust_nb_rx_tx_desc(uint8_t port_id, >>>> >>>> return 0; >>>> } >>>> + >>>> +int >>>> +rte_eth_dev_get_preferred_pool_ops(uint8_t port_id, char *pool) >>>> +{ >>>> + struct rte_eth_dev *dev; >>>> + const char *tmp; >>>> + >>>> + RTE_ETH_VALID_PORTID_OR_ERR_RET(port_id, -ENODEV); >>>> + >>>> + dev = &rte_eth_devices[port_id]; >>>> + >>>> + if (*dev->dev_ops->get_preferred_pool_ops == NULL) { >>>> + tmp = rte_eal_mbuf_default_mempool_ops(); >>>> + snprintf(pool, RTE_MBUF_POOL_OPS_NAMESIZE, "%s", tmp); >>>> + return 0; >>>> + } >>>> + return (*dev->dev_ops->get_preferred_pool_ops)(dev, pool); >>>> +} >>> I think adding the length of the pool buffer to the function arguments >>> would be better: only documenting that the length is >>> RTE_MBUF_POOL_OPS_NAMESIZE looks a bit weak to me, because if one day it >>> changes to another value, the users of the function may not notice it >>> (no ABI/API change). >>> >>> >>> One more comment: it would be helpful to have one user of this API in >>> the example apps or testpmd. >> >> Yes. I will add in v3. Thanks. >> >>> Olivier >> >> >
