[v5,2/7] ethdev: allocate max space for internal queue array
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Commit Message
At queue configure stage always allocate space for maximum possible
number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
pointer to internal queue data without extra checking of current number
of configured queues.
That would help in future to hide rte_eth_dev and related structures.
It means that from now on, each ethdev port will always consume:
((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
bytes of memory for its queue pointers.
With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
---
lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
1 file changed, 9 insertions(+), 27 deletions(-)
Comments
On 10/7/21 2:27 PM, Konstantin Ananyev wrote:
> At queue configure stage always allocate space for maximum possible
> number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
> That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
> pointer to internal queue data without extra checking of current number
> of configured queues.
> That would help in future to hide rte_eth_dev and related structures.
> It means that from now on, each ethdev port will always consume:
> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
> bytes of memory for its queue pointers.
> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
>
> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> ---
> lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
> 1 file changed, 9 insertions(+), 27 deletions(-)
>
> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> index ed37f8871b..c8abda6dd7 100644
> --- a/lib/ethdev/rte_ethdev.c
> +++ b/lib/ethdev/rte_ethdev.c
> @@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>
> if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
> dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
> - sizeof(dev->data->rx_queues[0]) * nb_queues,
> + sizeof(dev->data->rx_queues[0]) *
> + RTE_MAX_QUEUES_PER_PORT,
> RTE_CACHE_LINE_SIZE);
Looking at it I have few questions:
1. Why is nb_queues == 0 case kept as an exception? Yes,
strictly speaking it is not the problem of the patch,
DPDK will still segfault (non-debug build) if I
allocate Tx queues only but call rte_eth_rx_burst().
After reading the patch description I thought that
we're trying to address it.
2. Why do we need to allocate memory dynamically?
Can we just make rx_queues an array of appropriate size?
May be wasting 512K unconditionally is too much.
3. If wasting 512K is too much, I'd consider to move
allocation to eth_dev_get(). If
> if (dev->data->rx_queues == NULL) {
> dev->data->nb_rx_queues = 0;
> @@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>
> rxq = dev->data->rx_queues;
>
> - for (i = nb_queues; i < old_nb_queues; i++)
> + for (i = nb_queues; i < old_nb_queues; i++) {
> (*dev->dev_ops->rx_queue_release)(rxq[i]);
> - rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
> - RTE_CACHE_LINE_SIZE);
> - if (rxq == NULL)
> - return -(ENOMEM);
> - if (nb_queues > old_nb_queues) {
> - uint16_t new_qs = nb_queues - old_nb_queues;
> -
> - memset(rxq + old_nb_queues, 0,
> - sizeof(rxq[0]) * new_qs);
> + rxq[i] = NULL;
It looks like the patch should be rebased on top of
next-net main because of queue release patches.
[snip]
> > At queue configure stage always allocate space for maximum possible
> > number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
> > That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
> > pointer to internal queue data without extra checking of current number
> > of configured queues.
> > That would help in future to hide rte_eth_dev and related structures.
> > It means that from now on, each ethdev port will always consume:
> > ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
> > bytes of memory for its queue pointers.
> > With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
> >
> > Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> > ---
> > lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
> > 1 file changed, 9 insertions(+), 27 deletions(-)
> >
> > diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> > index ed37f8871b..c8abda6dd7 100644
> > --- a/lib/ethdev/rte_ethdev.c
> > +++ b/lib/ethdev/rte_ethdev.c
> > @@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
> >
> > if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
> > dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
> > - sizeof(dev->data->rx_queues[0]) * nb_queues,
> > + sizeof(dev->data->rx_queues[0]) *
> > + RTE_MAX_QUEUES_PER_PORT,
> > RTE_CACHE_LINE_SIZE);
>
> Looking at it I have few questions:
> 1. Why is nb_queues == 0 case kept as an exception? Yes,
> strictly speaking it is not the problem of the patch,
> DPDK will still segfault (non-debug build) if I
> allocate Tx queues only but call rte_eth_rx_burst().
eth_dev_rx_queue_config(.., nb_queues=0) is used in few places to clean-up things.
> After reading the patch description I thought that
> we're trying to address it.
We do, though I can't see how we can address it in this patch.
Though it is a good idea - I think I can add extra check in eth_dev_fp_ops_setup()
or around and setup RX function pointers only when dev->data->rx_queues != NULL.
Same for TX.
> 2. Why do we need to allocate memory dynamically?
> Can we just make rx_queues an array of appropriate size?
Pavan already asked same question.
My answer to him:
Yep we can, and yes it will simplify this peace of code.
The main reason I decided no to do this change now -
it will change layout of the_eth_dev_data structure.
In this series I tried to mininize(/avoid) changes in rte_eth_dev and rte_eth_dev_data,
as much as possible to avoid any unforeseen performance and functional impacts.
If we'll manage to make rte_eth_dev and rte_eth_dev_data private we can in future
consider that one and other changes in rte_eth_dev and rte_eth_dev_data layouts
without worrying about ABI breakage
> May be wasting 512K unconditionally is too much.
> 3. If wasting 512K is too much, I'd consider to move
> allocation to eth_dev_get(). If
Don't understand where 512KB came from.
each ethdev port will always consume:
((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
bytes of memory for its queue pointers.
With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
> > if (dev->data->rx_queues == NULL) {
> > dev->data->nb_rx_queues = 0;
> > @@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
> >
> > rxq = dev->data->rx_queues;
> >
> > - for (i = nb_queues; i < old_nb_queues; i++)
> > + for (i = nb_queues; i < old_nb_queues; i++) {
> > (*dev->dev_ops->rx_queue_release)(rxq[i]);
> > - rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
> > - RTE_CACHE_LINE_SIZE);
> > - if (rxq == NULL)
> > - return -(ENOMEM);
> > - if (nb_queues > old_nb_queues) {
> > - uint16_t new_qs = nb_queues - old_nb_queues;
> > -
> > - memset(rxq + old_nb_queues, 0,
> > - sizeof(rxq[0]) * new_qs);
> > + rxq[i] = NULL;
>
> It looks like the patch should be rebased on top of
> next-net main because of queue release patches.
>
> [snip]
On 10/11/21 7:25 PM, Ananyev, Konstantin wrote:
>
>
>>> At queue configure stage always allocate space for maximum possible
>>> number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
>>> That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
>>> pointer to internal queue data without extra checking of current number
>>> of configured queues.
>>> That would help in future to hide rte_eth_dev and related structures.
>>> It means that from now on, each ethdev port will always consume:
>>> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
>>> bytes of memory for its queue pointers.
>>> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
>>>
>>> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
>>> ---
>>> lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
>>> 1 file changed, 9 insertions(+), 27 deletions(-)
>>>
>>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
>>> index ed37f8871b..c8abda6dd7 100644
>>> --- a/lib/ethdev/rte_ethdev.c
>>> +++ b/lib/ethdev/rte_ethdev.c
>>> @@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>>>
>>> if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
>>> dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
>>> - sizeof(dev->data->rx_queues[0]) * nb_queues,
>>> + sizeof(dev->data->rx_queues[0]) *
>>> + RTE_MAX_QUEUES_PER_PORT,
>>> RTE_CACHE_LINE_SIZE);
>>
>> Looking at it I have few questions:
>> 1. Why is nb_queues == 0 case kept as an exception? Yes,
>> strictly speaking it is not the problem of the patch,
>> DPDK will still segfault (non-debug build) if I
>> allocate Tx queues only but call rte_eth_rx_burst().
>
> eth_dev_rx_queue_config(.., nb_queues=0) is used in few places to clean-up things.
No, as far as I know. For Tx only application (e.g. traffic generator)
it is 100% legal to configure with tx_queues=X, rx_queues=0.
The same is for Rx only application (e.g. packet capture).
>
>> After reading the patch description I thought that
>> we're trying to address it.
>
> We do, though I can't see how we can address it in this patch.
> Though it is a good idea - I think I can add extra check in eth_dev_fp_ops_setup()
> or around and setup RX function pointers only when dev->data->rx_queues != NULL.
> Same for TX.
You don't need to care about these pointers, if these arrays are
always allocated. See (3) below.
>
>> 2. Why do we need to allocate memory dynamically?
>> Can we just make rx_queues an array of appropriate size?
>
> Pavan already asked same question.
> My answer to him:
> Yep we can, and yes it will simplify this peace of code.
> The main reason I decided no to do this change now -
> it will change layout of the_eth_dev_data structure.
> In this series I tried to mininize(/avoid) changes in rte_eth_dev and rte_eth_dev_data,
> as much as possible to avoid any unforeseen performance and functional impacts.
> If we'll manage to make rte_eth_dev and rte_eth_dev_data private we can in future
> consider that one and other changes in rte_eth_dev and rte_eth_dev_data layouts
> without worrying about ABI breakage
Thanks a lot. Makes sense.
>> May be wasting 512K unconditionally is too much.
>> 3. If wasting 512K is too much, I'd consider to move
>> allocation to eth_dev_get(). If
>
> Don't understand where 512KB came from.
32 port * 1024 queues * 2 types * 8 pointer size
if we allocate as in (2) above.
> each ethdev port will always consume:
> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
> bytes of memory for its queue pointers.
> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
IMHO it will be a bit nicer if queue pointers arrays are allocated
on device get if size is fixed. It is just a suggestion. If you
disagree, feel free to drop it.
>>> if (dev->data->rx_queues == NULL) {
>>> dev->data->nb_rx_queues = 0;
>>> @@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>>>
>>> rxq = dev->data->rx_queues;
>>>
>>> - for (i = nb_queues; i < old_nb_queues; i++)
>>> + for (i = nb_queues; i < old_nb_queues; i++) {
>>> (*dev->dev_ops->rx_queue_release)(rxq[i]);
>>> - rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
>>> - RTE_CACHE_LINE_SIZE);
>>> - if (rxq == NULL)
>>> - return -(ENOMEM);
>>> - if (nb_queues > old_nb_queues) {
>>> - uint16_t new_qs = nb_queues - old_nb_queues;
>>> -
>>> - memset(rxq + old_nb_queues, 0,
>>> - sizeof(rxq[0]) * new_qs);
>>> + rxq[i] = NULL;
>>
>> It looks like the patch should be rebased on top of
>> next-net main because of queue release patches.
>>
>> [snip]
> >>> At queue configure stage always allocate space for maximum possible
> >>> number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
> >>> That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
> >>> pointer to internal queue data without extra checking of current number
> >>> of configured queues.
> >>> That would help in future to hide rte_eth_dev and related structures.
> >>> It means that from now on, each ethdev port will always consume:
> >>> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
> >>> bytes of memory for its queue pointers.
> >>> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
> >>>
> >>> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> >>> ---
> >>> lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
> >>> 1 file changed, 9 insertions(+), 27 deletions(-)
> >>>
> >>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
> >>> index ed37f8871b..c8abda6dd7 100644
> >>> --- a/lib/ethdev/rte_ethdev.c
> >>> +++ b/lib/ethdev/rte_ethdev.c
> >>> @@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
> >>>
> >>> if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
> >>> dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
> >>> - sizeof(dev->data->rx_queues[0]) * nb_queues,
> >>> + sizeof(dev->data->rx_queues[0]) *
> >>> + RTE_MAX_QUEUES_PER_PORT,
> >>> RTE_CACHE_LINE_SIZE);
> >>
> >> Looking at it I have few questions:
> >> 1. Why is nb_queues == 0 case kept as an exception? Yes,
> >> strictly speaking it is not the problem of the patch,
> >> DPDK will still segfault (non-debug build) if I
> >> allocate Tx queues only but call rte_eth_rx_burst().
> >
> > eth_dev_rx_queue_config(.., nb_queues=0) is used in few places to clean-up things.
>
> No, as far as I know. For Tx only application (e.g. traffic generator)
> it is 100% legal to configure with tx_queues=X, rx_queues=0.
> The same is for Rx only application (e.g. packet capture).
Yes, that is valid config for sure.
I just pointed that simply ignoring 'nb_queues' value and
always allocating space for max possible queues, i.e:
eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
{
....
- if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
+ if (dev->data->rx_queues == NULL) {
wouldn't work, as right now nb_queues == 0 has extra special meaning -
do final cleanup and free dev->data->rx_queues.
But re-reading the text below, it seems that I misunderstood you
and it probably wasn't your intention anyway.
>
> >
> >> After reading the patch description I thought that
> >> we're trying to address it.
> >
> > We do, though I can't see how we can address it in this patch.
> > Though it is a good idea - I think I can add extra check in eth_dev_fp_ops_setup()
> > or around and setup RX function pointers only when dev->data->rx_queues != NULL.
> > Same for TX.
>
> You don't need to care about these pointers, if these arrays are
> always allocated. See (3) below.
>
> >
> >> 2. Why do we need to allocate memory dynamically?
> >> Can we just make rx_queues an array of appropriate size?
> >
> > Pavan already asked same question.
> > My answer to him:
> > Yep we can, and yes it will simplify this peace of code.
> > The main reason I decided no to do this change now -
> > it will change layout of the_eth_dev_data structure.
> > In this series I tried to mininize(/avoid) changes in rte_eth_dev and rte_eth_dev_data,
> > as much as possible to avoid any unforeseen performance and functional impacts.
> > If we'll manage to make rte_eth_dev and rte_eth_dev_data private we can in future
> > consider that one and other changes in rte_eth_dev and rte_eth_dev_data layouts
> > without worrying about ABI breakage
>
> Thanks a lot. Makes sense.
>
> >> May be wasting 512K unconditionally is too much.
> >> 3. If wasting 512K is too much, I'd consider to move
> >> allocation to eth_dev_get(). If
> >
> > Don't understand where 512KB came from.
>
> 32 port * 1024 queues * 2 types * 8 pointer size
> if we allocate as in (2) above.
>
> > each ethdev port will always consume:
> > ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
> > bytes of memory for its queue pointers.
> > With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
>
> IMHO it will be a bit nicer if queue pointers arrays are allocated
> on device get if size is fixed. It is just a suggestion. If you
> disagree, feel free to drop it.
You mean - allocate these arrays somewhere at rte_eth_dev_allocate() path?
That sounds like an interesting idea, but seems too drastic to me at that stage.
>
> >>> if (dev->data->rx_queues == NULL) {
> >>> dev->data->nb_rx_queues = 0;
> >>> @@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
> >>>
> >>> rxq = dev->data->rx_queues;
> >>>
> >>> - for (i = nb_queues; i < old_nb_queues; i++)
> >>> + for (i = nb_queues; i < old_nb_queues; i++) {
> >>> (*dev->dev_ops->rx_queue_release)(rxq[i]);
> >>> - rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
> >>> - RTE_CACHE_LINE_SIZE);
> >>> - if (rxq == NULL)
> >>> - return -(ENOMEM);
> >>> - if (nb_queues > old_nb_queues) {
> >>> - uint16_t new_qs = nb_queues - old_nb_queues;
> >>> -
> >>> - memset(rxq + old_nb_queues, 0,
> >>> - sizeof(rxq[0]) * new_qs);
> >>> + rxq[i] = NULL;
> >>
> >> It looks like the patch should be rebased on top of
> >> next-net main because of queue release patches.
> >>
> >> [snip]
On 10/12/21 2:06 AM, Ananyev, Konstantin wrote:
>>>>> At queue configure stage always allocate space for maximum possible
>>>>> number (RTE_MAX_QUEUES_PER_PORT) of queue pointers.
>>>>> That will allow 'fast' inline functions (eth_rx_burst, etc.) to refer
>>>>> pointer to internal queue data without extra checking of current number
>>>>> of configured queues.
>>>>> That would help in future to hide rte_eth_dev and related structures.
>>>>> It means that from now on, each ethdev port will always consume:
>>>>> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
>>>>> bytes of memory for its queue pointers.
>>>>> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
>>>>>
>>>>> Signed-off-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
>>>>> ---
>>>>> lib/ethdev/rte_ethdev.c | 36 +++++++++---------------------------
>>>>> 1 file changed, 9 insertions(+), 27 deletions(-)
>>>>>
>>>>> diff --git a/lib/ethdev/rte_ethdev.c b/lib/ethdev/rte_ethdev.c
>>>>> index ed37f8871b..c8abda6dd7 100644
>>>>> --- a/lib/ethdev/rte_ethdev.c
>>>>> +++ b/lib/ethdev/rte_ethdev.c
>>>>> @@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>>>>>
>>>>> if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
>>>>> dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
>>>>> - sizeof(dev->data->rx_queues[0]) * nb_queues,
>>>>> + sizeof(dev->data->rx_queues[0]) *
>>>>> + RTE_MAX_QUEUES_PER_PORT,
>>>>> RTE_CACHE_LINE_SIZE);
>>>>
>>>> Looking at it I have few questions:
>>>> 1. Why is nb_queues == 0 case kept as an exception? Yes,
>>>> strictly speaking it is not the problem of the patch,
>>>> DPDK will still segfault (non-debug build) if I
>>>> allocate Tx queues only but call rte_eth_rx_burst().
>>>
>>> eth_dev_rx_queue_config(.., nb_queues=0) is used in few places to clean-up things.
>>
>> No, as far as I know. For Tx only application (e.g. traffic generator)
>> it is 100% legal to configure with tx_queues=X, rx_queues=0.
>> The same is for Rx only application (e.g. packet capture).
>
> Yes, that is valid config for sure.
> I just pointed that simply ignoring 'nb_queues' value and
> always allocating space for max possible queues, i.e:
>
> eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
> {
> ....
> - if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
> + if (dev->data->rx_queues == NULL) {
> wouldn't work, as right now nb_queues == 0 has extra special meaning -
> do final cleanup and free dev->data->rx_queues.
> But re-reading the text below, it seems that I misunderstood you
> and it probably wasn't your intention anyway.
>
>>
>>>
>>>> After reading the patch description I thought that
>>>> we're trying to address it.
>>>
>>> We do, though I can't see how we can address it in this patch.
>>> Though it is a good idea - I think I can add extra check in eth_dev_fp_ops_setup()
>>> or around and setup RX function pointers only when dev->data->rx_queues != NULL.
>>> Same for TX.
>>
>> You don't need to care about these pointers, if these arrays are
>> always allocated. See (3) below.
>>
>>>
>>>> 2. Why do we need to allocate memory dynamically?
>>>> Can we just make rx_queues an array of appropriate size?
>>>
>>> Pavan already asked same question.
>>> My answer to him:
>>> Yep we can, and yes it will simplify this peace of code.
>>> The main reason I decided no to do this change now -
>>> it will change layout of the_eth_dev_data structure.
>>> In this series I tried to mininize(/avoid) changes in rte_eth_dev and rte_eth_dev_data,
>>> as much as possible to avoid any unforeseen performance and functional impacts.
>>> If we'll manage to make rte_eth_dev and rte_eth_dev_data private we can in future
>>> consider that one and other changes in rte_eth_dev and rte_eth_dev_data layouts
>>> without worrying about ABI breakage
>>
>> Thanks a lot. Makes sense.
>>
>>>> May be wasting 512K unconditionally is too much.
>>>> 3. If wasting 512K is too much, I'd consider to move
>>>> allocation to eth_dev_get(). If
>>>
>>> Don't understand where 512KB came from.
>>
>> 32 port * 1024 queues * 2 types * 8 pointer size
>> if we allocate as in (2) above.
>>
>>> each ethdev port will always consume:
>>> ((2*sizeof(uintptr_t))* RTE_MAX_QUEUES_PER_PORT)
>>> bytes of memory for its queue pointers.
>>> With RTE_MAX_QUEUES_PER_PORT==1024 (default value) it is 16KB per port.
>>
>> IMHO it will be a bit nicer if queue pointers arrays are allocated
>> on device get if size is fixed. It is just a suggestion. If you
>> disagree, feel free to drop it.
>
> You mean - allocate these arrays somewhere at rte_eth_dev_allocate() path?
Yes, eth_dev_get() mentioned above is called from
rte_eth_dev_allocate().
> That sounds like an interesting idea, but seems too drastic to me at that stage.
Yes, of course, we can address it later.
>
>>
>>>>> if (dev->data->rx_queues == NULL) {
>>>>> dev->data->nb_rx_queues = 0;
>>>>> @@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
>>>>>
>>>>> rxq = dev->data->rx_queues;
>>>>>
>>>>> - for (i = nb_queues; i < old_nb_queues; i++)
>>>>> + for (i = nb_queues; i < old_nb_queues; i++) {
>>>>> (*dev->dev_ops->rx_queue_release)(rxq[i]);
>>>>> - rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
>>>>> - RTE_CACHE_LINE_SIZE);
>>>>> - if (rxq == NULL)
>>>>> - return -(ENOMEM);
>>>>> - if (nb_queues > old_nb_queues) {
>>>>> - uint16_t new_qs = nb_queues - old_nb_queues;
>>>>> -
>>>>> - memset(rxq + old_nb_queues, 0,
>>>>> - sizeof(rxq[0]) * new_qs);
>>>>> + rxq[i] = NULL;
>>>>
>>>> It looks like the patch should be rebased on top of
>>>> next-net main because of queue release patches.
>>>>
>>>> [snip]
>
@@ -897,7 +897,8 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
if (dev->data->rx_queues == NULL && nb_queues != 0) { /* first time configuration */
dev->data->rx_queues = rte_zmalloc("ethdev->rx_queues",
- sizeof(dev->data->rx_queues[0]) * nb_queues,
+ sizeof(dev->data->rx_queues[0]) *
+ RTE_MAX_QUEUES_PER_PORT,
RTE_CACHE_LINE_SIZE);
if (dev->data->rx_queues == NULL) {
dev->data->nb_rx_queues = 0;
@@ -908,21 +909,11 @@ eth_dev_rx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
rxq = dev->data->rx_queues;
- for (i = nb_queues; i < old_nb_queues; i++)
+ for (i = nb_queues; i < old_nb_queues; i++) {
(*dev->dev_ops->rx_queue_release)(rxq[i]);
- rxq = rte_realloc(rxq, sizeof(rxq[0]) * nb_queues,
- RTE_CACHE_LINE_SIZE);
- if (rxq == NULL)
- return -(ENOMEM);
- if (nb_queues > old_nb_queues) {
- uint16_t new_qs = nb_queues - old_nb_queues;
-
- memset(rxq + old_nb_queues, 0,
- sizeof(rxq[0]) * new_qs);
+ rxq[i] = NULL;
}
- dev->data->rx_queues = rxq;
-
} else if (dev->data->rx_queues != NULL && nb_queues == 0) {
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->rx_queue_release, -ENOTSUP);
@@ -1137,8 +1128,9 @@ eth_dev_tx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
if (dev->data->tx_queues == NULL && nb_queues != 0) { /* first time configuration */
dev->data->tx_queues = rte_zmalloc("ethdev->tx_queues",
- sizeof(dev->data->tx_queues[0]) * nb_queues,
- RTE_CACHE_LINE_SIZE);
+ sizeof(dev->data->tx_queues[0]) *
+ RTE_MAX_QUEUES_PER_PORT,
+ RTE_CACHE_LINE_SIZE);
if (dev->data->tx_queues == NULL) {
dev->data->nb_tx_queues = 0;
return -(ENOMEM);
@@ -1148,21 +1140,11 @@ eth_dev_tx_queue_config(struct rte_eth_dev *dev, uint16_t nb_queues)
txq = dev->data->tx_queues;
- for (i = nb_queues; i < old_nb_queues; i++)
+ for (i = nb_queues; i < old_nb_queues; i++) {
(*dev->dev_ops->tx_queue_release)(txq[i]);
- txq = rte_realloc(txq, sizeof(txq[0]) * nb_queues,
- RTE_CACHE_LINE_SIZE);
- if (txq == NULL)
- return -ENOMEM;
- if (nb_queues > old_nb_queues) {
- uint16_t new_qs = nb_queues - old_nb_queues;
-
- memset(txq + old_nb_queues, 0,
- sizeof(txq[0]) * new_qs);
+ txq[i] = NULL;
}
- dev->data->tx_queues = txq;
-
} else if (dev->data->tx_queues != NULL && nb_queues == 0) {
RTE_FUNC_PTR_OR_ERR_RET(*dev->dev_ops->tx_queue_release, -ENOTSUP);