Re: [dpdk-dev] [PATCH] vhost: make vhost lockless enqueue configurable

["Xie, Huawei" <huawei.xie@intel.com>]

On 4/29/2015 7:57 PM, Thomas Monjalon wrote:
> 2015-04-29 13:38 GMT+02:00 Panu Matilainen <pmatilai@redhat.com>:
>> On 04/29/2015 02:29 PM, Huawei Xie wrote:
>>> vhost enabled vSwitch could have their own thread-safe vring enqueue
>>> policy.
>>> Add the RTE_LIBRTE_VHOST_LOCKLESS_ENQ macro for vhost lockless enqueue.
>>> Turn it off by default.
>>>
>>> Signed-off-by: Huawei Xie <huawei.xie@intel.com>
>>> ---
>>>   config/common_linuxapp        |  1 +
>>>   lib/librte_vhost/vhost_rxtx.c | 24 +++++++++++++++++++++++-
>>>   2 files changed, 24 insertions(+), 1 deletion(-)
>>>
>>> diff --git a/config/common_linuxapp b/config/common_linuxapp
>>> index 0078dc9..7f59499 100644
>>> --- a/config/common_linuxapp
>>> +++ b/config/common_linuxapp
>>> @@ -421,6 +421,7 @@ CONFIG_RTE_KNI_VHOST_DEBUG_TX=n
>>>   #
>>>   CONFIG_RTE_LIBRTE_VHOST=n
>>>   CONFIG_RTE_LIBRTE_VHOST_USER=y
>>> +CONFIG_RTE_LIBRTE_VHOST_LOCKLESS_ENQ=n
>>>   CONFIG_RTE_LIBRTE_VHOST_DEBUG=n
> [...]
>> These things should be runtime configurable, not build options. Please do
>> not assume everybody builds DPDK separately for each and every application
>> that might ever be.
> +1
> Adding new build options must be exceptions and very well justified.

Thomas:
Though we could make per queue/device run time configurable, i feel it
might not make sense that per queue/device has different behavior.
 To ease the implementation, i would provide an API to configure the
global lock less behavior, and by default, lockess enqueue will be disabled.
Thoughts?

>
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