Re: Regression associated with commit c8628155ece3 - "tcp: reduceout_of_order memory use"

[Larry Finger]

On 08/22/2012 12:15 AM, Eric Dumazet wrote:
> This particular commit is the start of a patches batch that ended in the
> generic TCP coalescing mechanism.
>
> It is known to have problem on drivers doing skb_clone() in their rx
> path.
>
> Current kernels should be ok, because coalescing doesnt happen if the
> destination skb is cloned (skb_cloned(to) in skb_try_coalesce())

The skb_clone() call is not the source of the problem for r8712u, as it is only 
used when a memory allocation fails, which is not happening. The suggestion did 
lead to another patch that I had been preparing. The initial allocation of RX 
buffers used a size of 30720 bytes, while 9100 is sufficient to allow 
aggregation. Upon reducing the buffer size, the driver now works for me. I am 
now awaiting tests by the OP on the Red Hat bugzilla before sending the patch 
upstream.

So far, no ideas for the problem in connecting to WPA1 networks.

Larry


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/