[PATCH v2] net/mlx5: fix flow workspace destruction

[Matan Azrad]

From: Bing Zhao <bingz at nvidia.com>
> PMD uses pthread key to allocate and access per thread flow workspace
> memory buffers.
> 
> PMD registered a key destructor function to clean up flow workspace buffers.
> However, the key destructor was not called by the pthread library.
> 
> The patch keeps track of per-thread flow workspaces in PMD.
> Flow workspaces memory release is activated from PMD destructor.
> 
> In the meanwhile, workspace buffer and RSS queues array are allocated in a
> single memory chunk with this patch. The maximal number of queues
> RTE_ETH_RSS_RETA_SIZE_512 is chosen. Then the workspace adjustment can
> be removed to reduce the software hiccup:
>   1. realloc and content copy
>   2. spinlock acquire and release
> 
> Fixes: 5d55a494f4e6 ("net/mlx5: split multi-thread flow handling per OS")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Gregory Etelson <getelson at nvidia.com>
> Signed-off-by: Bing Zhao <bingz at nvidia.com>
Acked-by: Matan Azrad <matan at nvidia.com>