Re: [RFC PATCH] sock: add SO_RCVQUEUE_SIZE getsockopt

[Eric Dumazet <edumazet@google.com>]

On Mon, Mar 13, 2017 at 8:59 AM, Josh Hunt <johunt@akamai.com> wrote:
> Allows application to read the amount of data sitting in the receive
> queue.
>
> Signed-off-by: Josh Hunt <johunt@akamai.com>
> ---
>
> A team here is looking for a way to get the amount of data in a UDP socket's
> receive queue. It seems like this should be SIOCINQ, but for UDP sockets that
> returns the size of the next pending datagram. I implemented the patch below,
> but am wondering if this is the right place for this change? I was debating
> between this or a new UDP ioctl.

But what is the 'amount of data' exactly ?
Number of packets, amount of bytes to read from these packets ?

You chose to report kernel memory usage, which is not guaranteed to be
the same among kernels versions (or kernel configs)

If we export these internals, I would export the whole thing, like we
did with netlink

ie tweak sock_diag_put_meminfo() and export the SK_MEMINFO_VARS

So that we avoid adding other options in the future.