RE: [PATCH] net : rps : supoort a single flow to use rps

From: David Laight
Date: Wed Jun 29 2022 - 05:09:47 EST


....
> I'd suggest to use some flags bitfield instead, so it would be way
> more scalable and at the same time have the pre-determined size. Ar
> per several LKML discussions, `bool` may have different size and
> logics depending on architecture and compiler, so when using it not
> on the stack inside a function, but in a structure, it might be not
> easy then to track cacheline layout etc.
> So, maybe
>
> unsigned long rps_flags;
> #define RPS_SINGLE_FLOW_ENABLE BIT(0)
>
> or even
>
> DECLARE_BITMAP(rps_flags);
> #define RPS_SINGLE_FLOW_ENABLE 0

I don't think BITMAPs are a good idea unless you really
need a lot of bits and (probably) locked accesses.

You can use C bitfields - the compiler doesn't (usually)
make too much of a 'pigs breakfast' of them unless you
needs to set/test multiple ones at the same time.

David

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