[PATCH v2] eal: add seqlock

[Mattias Rönnblom]

On 2022-03-30 16:26, Mattias Rönnblom wrote:
> A sequence lock (seqlock) is synchronization primitive which allows
> for data-race free, low-overhead, high-frequency reads, especially for
> data structures shared across many cores and which are updated with
> relatively infrequently.
>
>

<snip>

Some questions I have:

Is a variant of the seqlock without the spinlock required? The reason I 
left such out was that I thought that in most cases where only a single 
writer is used (or serialization is external to the seqlock), the 
spinlock overhead is negligible, since updates are relatively infrequent.

Should the rte_seqlock_read_retry() be called rte_seqlock_read_end(), or 
some third alternative? I wanted to make clear it's not just a "release 
the lock" function. You could use 
the|||__attribute__((warn_unused_result)) annotation to make clear the 
return value cannot be ignored, although I'm not sure DPDK ever use that 
attribute.


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