Re: [dpdk-dev] [PATCH 1/2] ethdev: make flow API primary/secondary process safe

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 4/16/2021 2:41 AM, fengchengwen wrote:
> We make a test on this patch, test result show that it works fine. Below is the detail:
> 
> HW: Kunpeng920 ARM Platform which is ARMv8
> NIC: Kunpeng920 SOC NIC
> OS: Linux centos-C3 5.12.0-rc4+
> DPDK: 21.02
> DRV: hns3
> 
> Start three process:
> ./testpmd -w 0000:bd:00.0 -l 67-68 --proc-type=auto -- -i --num-procs=3 --proc-id=0
> ./testpmd -w 0000:bd:00.0 -l 67-68 --proc-type=auto -- -i --num-procs=3 --proc-id=1
> ./testpmd -w 0000:bd:00.0 -l 69-70 --proc-type=auto -- -i --num-procs=3 --proc-id=2
> 
> Every process execute following steps:
> 1. create one fdir rule, eg: flow create 0 ingress pattern eth / ipv4 src is 192.168.110.26 / end actions queue index 0 / end
>     note: each process has different rules, so they will create success
> 2. create one rss rule
>     note: all process create the same rules, so they may create fail
> 3. flush all rules
> 4. goto step 1, loop again
> note: there are +10ms delay after step 1/2/3 because we run VBS script to inject command on windows.
> 
> The test lasted 12 hours, and there are no process crashes.
> 

Thanks Chengwen for testing, appreciated.

> 
> On 2021/4/14 21:06, Ferruh Yigit wrote:
>> On 3/16/2021 11:48 PM, Suanming Mou wrote:
>>> Hi Stephen,
>>>
>>>> -----Original Message-----
>>>> From: Stephen Hemminger <stephen@networkplumber.org>
>>>> Sent: Tuesday, March 16, 2021 3:27 AM
>>>> To: dev@dpdk.org
>>>> Cc: Stephen Hemminger <stephen@networkplumber.org>; Suanming Mou
>>>> <suanmingm@nvidia.com>
>>>> Subject: [PATCH 1/2] ethdev: make flow API primary/secondary process safe
>>>>
>>>> Posix mutex are not by default safe for protecting for usage from multiple
>>>> processes. The flow ops mutex could be used by both primary and secondary
>>>> processes.
>>>
>>> Process safe is something more widely scope. I assume it should be another feature but not a bugfix for thread-safe?
>>> And the fag RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE we have added is just thread safe.
>>>
>>
>> Hi Suanming,
>>
>> I think 'RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE' flag and what this patch address are different issues.
>>
>> 'RTE_ETH_DEV_FLOW_OPS_THREAD_SAFE' is to add/remove synchronization support for flow APIs, that is for thread safety as flag name suggests.
>>
>> This patch is to solve the problem for multi process, where commit log describes as posix mutex is not safe for multiple process.
>>
>>
>> Stephen,
>> Are you aware of any downside setting 'PTHREAD_PROCESS_SHARED' attribute to the mutex? Any possible performance implications?
>>
>> Ori,
>> Since mlx is heavily using the flow API, is it possible to test this patch? If there is no negative impact, I think we can get this patch, what do you think?
>>
>>>>
>>>> Bugzilla ID: 662
>>>> Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
>>>> Fixes: 80d1a9aff7f6 ("ethdev: make flow API thread safe")
>>>> Cc: suanmingm@nvidia.com
>>>> ---
>>>>    lib/librte_ethdev/rte_ethdev.c | 6 +++++-
>>>>    1 file changed, 5 insertions(+), 1 deletion(-)
>>>>
>>>> diff --git a/lib/librte_ethdev/rte_ethdev.c b/lib/librte_ethdev/rte_ethdev.c index
>>>> 6f514c388b4e..d1024df408a5 100644
>>>> --- a/lib/librte_ethdev/rte_ethdev.c
>>>> +++ b/lib/librte_ethdev/rte_ethdev.c
>>>> @@ -470,6 +470,7 @@ rte_eth_dev_allocate(const char *name)  {
>>>>        uint16_t port_id;
>>>>        struct rte_eth_dev *eth_dev = NULL;
>>>> +    pthread_mutexattr_t attr;
>>>>        size_t name_len;
>>>>
>>>>        name_len = strnlen(name, RTE_ETH_NAME_MAX_LEN); @@ -506,7
>>>> +507,10 @@ rte_eth_dev_allocate(const char *name)
>>>>        strlcpy(eth_dev->data->name, name, sizeof(eth_dev->data->name));
>>>>        eth_dev->data->port_id = port_id;
>>>>        eth_dev->data->mtu = RTE_ETHER_MTU;
>>>> -    pthread_mutex_init(&eth_dev->data->flow_ops_mutex, NULL);
>>>> +
>>>> +    pthread_mutexattr_init(&attr);
>>>> +    pthread_mutexattr_setpshared(&attr, PTHREAD_PROCESS_SHARED);
>>>>
>>>> +    pthread_mutex_init(&eth_dev->data->flow_ops_mutex, &attr);
>>>>
>>>>    unlock:
>>>>        rte_spinlock_unlock(&eth_dev_shared_data->ownership_lock);
>>>> -- 
>>>> 2.30.2
>>>
>>
>>
>> .
>