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/ >> --- 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
