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From: "Xie, Huawei" <huawei.xie@intel.com>
To: Ilya Maximets <i.maximets@samsung.com>, Yuanhan Liu
 <yuanhan.liu@linux.intel.com>, Thomas Monjalon <thomas.monjalon@6wind.com>
Thread-Topic: [PATCH RFC 4/4] doc: add note about rte_vhost_enqueue_burst
 thread safety.
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Date: Mon, 22 Feb 2016 02:07:56 +0000
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Cc: "dev@dpdk.org" <dev@dpdk.org>, Dyasly Sergey <s.dyasly@samsung.com>
Subject: Re: [dpdk-dev] [PATCH RFC 4/4] doc: add note about
 rte_vhost_enqueue_burst thread safety.
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On 2/19/2016 5:05 PM, Ilya Maximets wrote:=0A=
> On 19.02.2016 11:36, Xie, Huawei wrote:=0A=
>> On 2/19/2016 3:10 PM, Yuanhan Liu wrote:=0A=
>>> On Fri, Feb 19, 2016 at 09:32:43AM +0300, Ilya Maximets wrote:=0A=
>>>> Signed-off-by: Ilya Maximets <i.maximets@samsung.com>=0A=
>>>> ---=0A=
>>>>  doc/guides/prog_guide/thread_safety_dpdk_functions.rst | 1 +=0A=
>>>>  1 file changed, 1 insertion(+)=0A=
>>>>=0A=
>>>> diff --git a/doc/guides/prog_guide/thread_safety_dpdk_functions.rst b/=
doc/guides/prog_guide/thread_safety_dpdk_functions.rst=0A=
>>>> index 403e5fc..13a6c89 100644=0A=
>>>> --- a/doc/guides/prog_guide/thread_safety_dpdk_functions.rst=0A=
>>>> +++ b/doc/guides/prog_guide/thread_safety_dpdk_functions.rst=0A=
>>>> @@ -67,6 +67,7 @@ then locking, or some other form of mutual exclusion=
, is necessary.=0A=
>>>>  The ring library is based on a lockless ring-buffer algorithm that ma=
intains its original design for thread safety.=0A=
>>>>  Moreover, it provides high performance for either multi- or single-co=
nsumer/producer enqueue/dequeue operations.=0A=
>>>>  The mempool library is based on the DPDK lockless ring library and th=
erefore is also multi-thread safe.=0A=
>>>> +rte_vhost_enqueue_burst() is also thread safe because based on lockle=
ss ring-buffer algorithm like the ring library.=0A=
>>> FYI, Huawei meant to make rte_vhost_enqueue_burst() not be thread-safe,=
=0A=
>>> to aligh with the usage of rte_eth_tx_burst().=0A=
>>>=0A=
>>> 	--yliu=0A=
>> I have a patch to remove the lockless enqueue. Unless there is strong=0A=
>> reason, i prefer vhost PMD to behave like other PMDs, with no internal=
=0A=
>> lockless algorithm. In future, for people who really need it, we could=
=0A=
>> have dynamic/static switch to enable it.=0A=
=0A=
Thomas, what is your opinion on this and my patch removing lockless enqueue=
?=0A=
=0A=
> OK, got it. So, I think, this documentation patch may be dropped.=0A=
> Other patches of series still may be merged to fix existing issues and=0A=
> keep code in consistent state for the future.=0A=
> Am I right?=0A=
=0A=
Yes.=0A=
=0A=
> Best regards, Ilya Maximets.=0A=
>=0A=
=0A=