[dpdk-dev] [PATCH v3 1/5] net/ixgbevf: set the inter-interrupt interval for EITR.

[Tonghao Zhang]

On Thu, Apr 26, 2018 at 9:14 PM, Zhang, Qi Z <qi.z.zhang at intel.com> wrote:
> Hi Tonghao:
>         Would you submit v4 with Ferruh' s fix and also do a rebase on next-net?
Yes

> Thanks
> Qi
>
>> -----Original Message-----
>> From: dev [mailto:dev-bounces at dpdk.org] On Behalf Of Ferruh Yigit
>> Sent: Thursday, April 19, 2018 12:10 AM
>> To: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> Cc: Lu, Wenzhuo <wenzhuo.lu at intel.com>; Ananyev, Konstantin
>> <konstantin.ananyev at intel.com>; Xing, Beilei <beilei.xing at intel.com>; Dai,
>> Wei <wei.dai at intel.com>; dev at dpdk.org
>> Subject: Re: [dpdk-dev] [PATCH v3 1/5] net/ixgbevf: set the inter-interrupt
>> interval for EITR.
>>
>> On 4/18/2018 2:01 AM, Tonghao Zhang wrote:
>> > On Tue, Apr 17, 2018 at 7:00 PM, Ferruh Yigit <ferruh.yigit at intel.com>
>> wrote:
>> >> On 3/22/2018 1:01 PM, xiangxia.m.yue at gmail.com wrote:
>> >>> From: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> >>>
>> >>> Set EITR interval as default. This patch can improve the performance
>> >>> when we enable the rx-intrrupt to process the packets because we
>> >>> hope rx-intrrupt reduce CPU. For example, the 200us value of EITR
>> >>> makes the performance better with the low CPU.
>> >>>
>> >>> Users can configure the value of ITR via DPDK configuration.
>> >>>
>> >>> The default value of ITR is 500us, compatible with RSC of ixgbe PF,
>> >>> and next patch will use the default value.
>> >>>
>> >>> Signed-off-by: Tonghao Zhang <xiangxia.m.yue at gmail.com>
>> >>> ---
>> >>> v1 --> v2:
>> >>> use the configure file, for different user.
>> >>> suggested by Beilei Xing, http://dpdk.org/dev/patchwork/patch/32989
>> >>> ---
>> >>>  config/common_base               |  2 ++
>> >>>  drivers/net/ixgbe/ixgbe_ethdev.c |  7 +++++++
>> >>> drivers/net/ixgbe/ixgbe_ethdev.h | 12 ++++++++++++
>> >>>  3 files changed, 21 insertions(+)
>> >>>
>> >>> diff --git a/config/common_base b/config/common_base index
>> >>> e74febe..2e9fded 100644
>> >>> --- a/config/common_base
>> >>> +++ b/config/common_base
>> >>> @@ -196,6 +196,8 @@ CONFIG_RTE_LIBRTE_IXGBE_DEBUG_DRIVER=n
>> >>>  CONFIG_RTE_LIBRTE_IXGBE_PF_DISABLE_STRIP_CRC=n
>> >>>  CONFIG_RTE_IXGBE_INC_VECTOR=y
>> >>>  CONFIG_RTE_LIBRTE_IXGBE_BYPASS=n
>> >>> +# interval up to 1024 us
>> >>> +CONFIG_RTE_LIBRTE_IXGBE_ITR_INTERVAL=-1
>> >>
>> >> I can understand this is to let user to ability to fine tune this
>> >> value, the down side is when number of these kind of tune parameters
>> >> increased, it become confusing and config options because less useful or
>> perhaps useless.
>> >>
>> >> And overall we are trying to reduce config options we have.
>> >>
>> >> I can see there is already some default values in the header file,
>> >> what do you think removing the config option and go with default values
>> defined in header?
>> > v2 used the default value in header, but for configuring it like as
>> > i40e option (CONFIG_RTE_LIBRTE_IXGBE_ITR_INTERVAL).
>> > so v3 makes some changes. These patches may have been applied. For
>> > reducing config option, should we do it in individual patches to fix
>> > the ixgbe/i40e option ?
>>
>> Patches are still in Helin's tree, so this up to him how manage.
>> Since patches are not in main repo yet I would suggest making new version if
>> fits to Helin.
>>
>> >
>> >>>
>> >>>  #
>> >>>  # Compile burst-oriented I40E PMD driver diff --git
>> >>> a/drivers/net/ixgbe/ixgbe_ethdev.c
>> >>> b/drivers/net/ixgbe/ixgbe_ethdev.c
>> >>> index e67389f..495e72c 100644
>> >>> --- a/drivers/net/ixgbe/ixgbe_ethdev.c
>> >>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.c
>> >>> @@ -5780,6 +5780,13 @@ static void ixgbevf_set_vfta_all(struct
>> rte_eth_dev *dev, bool on)
>> >>>               if (vector_idx < base + intr_handle->nb_efd - 1)
>> >>>                       vector_idx++;
>> >>>       }
>> >>> +
>> >>> +     /* As RX queue setting above show, all queues use the vector 0.
>> >>> +      * Set only the ITR value of IXGBE_MISC_VEC_ID.
>> >>> +      */
>> >>> +     IXGBE_WRITE_REG(hw, IXGBE_VTEITR(IXGBE_MISC_VEC_ID),
>> >>> +
>> ixgbe_calc_itr_interval(RTE_LIBRTE_IXGBE_ITR_INTERVAL)
>> >>> +                     | IXGBE_EITR_CNT_WDIS);
>> >>>  }
>> >>>
>> >>>  /**
>> >>> diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h
>> >>> b/drivers/net/ixgbe/ixgbe_ethdev.h
>> >>> index 1db29bd..c779001 100644
>> >>> --- a/drivers/net/ixgbe/ixgbe_ethdev.h
>> >>> +++ b/drivers/net/ixgbe/ixgbe_ethdev.h
>> >>> @@ -58,6 +58,18 @@
>> >>>               IXGBE_EITR_ITR_INT_MASK)
>> >>>
>> >>>
>> >>> +#define IXGBE_QUEUE_ITR_INTERVAL_MAX 1024 /* 1024us */
>> >>> +#define IXGBE_QUEUE_ITR_INTERVAL_DEFAULT     500 /* 500us */
>> >>> +
>> >>> +static inline uint16_t
>> >>> +ixgbe_calc_itr_interval(int16_t interval) {
>> >>> +     if (interval < 0 || interval > IXGBE_QUEUE_ITR_INTERVAL_MAX)
>> >>> +             interval = IXGBE_QUEUE_ITR_INTERVAL_DEFAULT;
>> >>> +
>> >>> +     return IXGBE_EITR_INTERVAL_US(interval); }
>> >>> +
>> >>>  /* Loopback operation modes */
>> >>>  /* 82599 specific loopback operation types */
>> >>>  #define IXGBE_LPBK_82599_NONE   0x0 /* Default value. Loopback
>> is disabled. */
>> >>>
>> >>
>