Re: [dpdk-dev] [PATCH v4 1/4] ethdev: rename memzones allocated for DMA

[Thomas Monjalon <thomas@monjalon.net>]

12/10/2018 19:18, Thomas Monjalon:
> 12/10/2018 18:46, Andrew Rybchenko:
> > On 10/12/18 7:42 PM, Andrew Rybchenko wrote:
> > > On 10/12/18 7:40 PM, Thomas Monjalon wrote:
> > >> 12/10/2018 09:53, Andrew Rybchenko:
> > >>> On 10/12/18 12:02 AM, Thomas Monjalon wrote:
> > >>>> The helper rte_eth_dma_zone_reserve() is called by PMDs
> > >>>> when probing a new port.
> > >>>> It creates a new memzone with an unique name.
> > >>>> The name of this memzone was using the name of the driver
> > >>>> doing the probe.
> > >>>>
> > >>>> In order to avoid assigning the driver before the end of the probing
> > >>>> (next patch), the driver name is removed from these memzone names.
> > >>>> The ethdev name (data->name) is not used because it may be too long
> > >>>> and may be not set at this stage of probing.
> > >>>>
> > >>>> Syntax of old name: <driver>_<ring>_<port>_<queue>
> > >>>> Syntax of new name: eth_p<port>_q<queue>_<ring>
> > >>>>
> > >>>> Signed-off-by: Thomas Monjalon <thomas@monjalon.net>
> > >>>> ---
> > >>>>    lib/librte_ethdev/rte_ethdev.c | 5 ++---
> > >>>>    1 file changed, 2 insertions(+), 3 deletions(-)
> > >>>>
> > >>>> diff --git a/lib/librte_ethdev/rte_ethdev.c 
> > >>>> b/lib/librte_ethdev/rte_ethdev.c
> > >>>> index ef99f7068..ec443def5 100644
> > >>>> --- a/lib/librte_ethdev/rte_ethdev.c
> > >>>> +++ b/lib/librte_ethdev/rte_ethdev.c
> > >>>> @@ -3441,9 +3441,8 @@ rte_eth_dma_zone_reserve(const struct 
> > >>>> rte_eth_dev *dev, const char *ring_name,
> > >>>>        char z_name[RTE_MEMZONE_NAMESIZE];
> > >>>>        const struct rte_memzone *mz;
> > >>>>    -    snprintf(z_name, sizeof(z_name), "%s_%s_%d_%d",
> > >>>> -         dev->device->driver->name, ring_name,
> > >>>> -         dev->data->port_id, queue_id);
> > >>>> +    snprintf(z_name, sizeof(z_name), "eth_p%d_q%d_%s",
> > >>>> +         dev->data->port_id, queue_id, ring_name);
> > >>>>           mz = rte_memzone_lookup(z_name);
> > >>>>        if (mz)
> > >>> LGTM, but I've found more places where the pattern is duplicate
> > >>> and testpmd frightens me:
> > >>>    - app/test-pmd/config.c ring_dma_zone_lookup() which is used
> > >>>      to look at descriptors (looks like Intel specific since has
> > >>>      RTE_LIBRTE_I40E_16BYTE_RX_DESC conditional code)
> > >> >From what I see there is no access to rte_device.driver here,
> > >> except one in exit function.
> > >
> > > Yes, but testpmd will fail to find the memzone and command to
> > > take a look at descriptors will be broken.
> > >
> > > May be it is already broken etc. I think someone from Intel should
> > > comment it.
> > 
> > Potentially the following drivers may use it:
> > $ git grep -w \"rx_ring\" drivers/net/
> > drivers/net/avf/avf_rxtx.c:380: mz = rte_eth_dma_zone_reserve(dev, 
> > "rx_ring", queue_idx,
> > drivers/net/axgbe/axgbe_rxtx.c:91:      dma = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx, size, 12
> > drivers/net/cxgbe/sge.c:1878:            fwevtq ? "fwq_ring" : "rx_ring",
> > drivers/net/e1000/em_rxtx.c:1437:       rz = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx, rsize,
> > drivers/net/e1000/igb_rxtx.c:1734:      rz = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx, size,
> > drivers/net/fm10k/fm10k_ethdev.c:1878:  mz = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_id,
> > drivers/net/i40e/i40e_rxtx.c:1853:      rz = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx,
> > drivers/net/ixgbe/ixgbe_rxtx.c:2966:    rz = 
> > rte_eth_dma_zone_reserve(dev, "rx_ring", queue_idx,
> > drivers/net/nfp/nfp_net.c:1516: tz = rte_eth_dma_zone_reserve(dev, 
> > "rx_ring", queue_idx,
> 
> Excuse me, I really don't understand what you mean.

Oh, got it!
You mean the call to rte_memzone_lookup() must expect the new memzone name.
So I must update it here too, right?