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

[fengchengwen <fengchengwen@huawei.com>]

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.


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
>>
> 
> 
> .