Re: [PATCH net-next 0/9] inet_diag: remove three mutexes in diag dumps

[Willem de Bruijn <willemdebruijn.kernel@gmail.com>]

Eric Dumazet wrote:
> Surprisingly, inet_diag operations are serialized over a stack
> of three mutexes, giving legacy /proc based files an unfair
> advantage on modern hosts.
> 
> This series removes all of them, making inet_diag operations
> (eg iproute2/ss) fully parallel.
> 
> 1-2) Two first patches are adding data-race annotations
>      and can be backported to stable kernels.
> 
> 3-4) inet_diag_table_mutex can be replaced with RCU protection,
>      if we add corresponding protection against module unload.
> 
> 5-7) sock_diag_table_mutex can be replaced with RCU protection,
>      if we add corresponding protection against module unload.
> 
>  8)  sock_diag_mutex is removed, as the old bug it was
>      working around has been fixed more elegantly.
> 
>  9)  inet_diag_dump_icsk() can skip over empty buckets to reduce
>      spinlock contention.
> 
> Eric Dumazet (9):
>   sock_diag: annotate data-races around sock_diag_handlers[family]
>   inet_diag: annotate data-races around inet_diag_table[]
>   inet_diag: add module pointer to "struct inet_diag_handler"
>   inet_diag: allow concurrent operations
>   sock_diag: add module pointer to "struct sock_diag_handler"
>   sock_diag: allow concurrent operations
>   sock_diag: allow concurrent operation in sock_diag_rcv_msg()
>   sock_diag: remove sock_diag_mutex
>   inet_diag: skip over empty buckets

For the series:

Reviewed-by: Willem de Bruijn <willemb@google.com>