[dpdk-dev] [PATCH] eal: support using 0 as coremask for no-affinitization

[Burakov, Anatoly]

On 16-Feb-21 10:46 AM, Bruce Richardson wrote:
> On Tue, Feb 16, 2021 at 10:36:13AM +0000, Burakov, Anatoly wrote:
>> On 16-Feb-21 9:43 AM, Bruce Richardson wrote:
>>> Allow the user to specify that they don't want any core pinning from DPDK
>>> by passing in the coremask of 0.
>>> ---
>>
>> I haven't checked what happens yet, but down the line we also set affinity
>> for service cores as well as interrupt thread. what would be the semantics
>> of those in this particular case? do we want the same ability for service
>> cores (i.e. pick a non-affinitized core)? And where does interrupt thread
>> affinitize in this case (presumably, nowhere too)?
>>
> I have not checked the service core setup, because a) I forgot about them
> and b) I'm not sure how their affinity rules work with respect to the main
> lcore mask. On the other hand I did check out that the lcore mask for all
> non-pinned threads, or control threads, is the full set of bits as
> expected.
> 
> /Bruce
> 

+Harry,

I believe service core mask must not overlap with lcore masks, so 
presumably using 0 as lcore mask would make it so that any service core 
mask will be valid (which is presumably what we want?). Should service 
cores also have a "just pick a core" parameter?

I'm assuming this use-case is explicitly avoiding the CPU/memory/NIA 
NUMA affinity question, so i'm not bringing it up :)

-- 
Thanks,
Anatoly