Re: [dpdk-dev] 【Some Questions About Multi-Process Resource Cleaning】

[oulijun <oulijun@huawei.com>]

在 2021/2/10 23:59, Burakov, Anatoly 写道:
> On 04-Feb-21 11:47 AM, oulijun wrote:
>>
>>
>>> Hi,
>>>
>>> Sorry your questions are quite confused.
>>> Please start explaining what is the problem you are trying to solve.
>> Start the master and slave processes at the same time, and then run 
>> the kill -9 command to kill the slave processes.
>> The slave process should call rte_eal_cleanup to release resources. 
>> But I find that there is no release from the process,
>> and I think there is a resource leak.
> 
> To add to others, not only there will be a resource leak whenever you're 
> killing processes with SIGKILL, the cleanup is up to individual 
> applications to perform. It is not the responsibility of the DPDK 
> library itself to install signal handlers and handle SIGINT or others.
> 
> So, if the application leaks resources, it's up to the application to 
> catch termination signals and clean up after itself. Unfortunately, 
> there's also no way to recover any leaked memory that has gone out this 
> way: there is no garbage collection or any similar mechanism in DPDK. 
> Therefore, while primary-secondary process model is slightly more 
> resilient than single-process model, there are no mechanisms to reclaim 
> memory from a crashed process, and crashing secondary process still 
> leads to undefined behavior.
> 
> For example, a crashing secondary process may crash while holding a 
> lock, and there's no way to release the lock without reinitializing the 
> lock (which often means restart). The secondary process may also crash 
> while processing buffers, and those in-flight buffers will be lost. 
> There's nothing we can do about it, at least for now.
> 
Thank you very much for your response.