[PATCH 1/2] ehea: fix delayed packet processing
David Miller
davem at davemloft.net
Thu Jun 17 11:05:40 EST 2010
From: Jay Vosburgh <fubar at us.ibm.com>
Date: Tue, 15 Jun 2010 09:45:47 -0700
> Jan-Bernd Themann <ossthema at de.ibm.com> wrote:
>
>>In the eHEA poll function an rmb() is required. Without that some packets
>>on the receive queue are not seen and thus delayed until the next interrupt
>>is handled for the same receive queue.
>>
>>Signed-off-by: Jan-Bernd Themann <themann at de.ibm.com>
>
> To add a bit of background, this could manifest during a netperf
> TCP_RR or UDP_RR on an otherwise idle network. TCP would occasionally
> retransmit, but then both the original segment and the retransmission
> would simultaneously appear at the receiver. For UDP_RR, message sizes
> in excess of the mtu would occasionally "lose" an IP fragment, and
> eventually IP reassembly would time out.
>
> -J
>
> Signed-off-by: Jay Vosburgh <fubar at us.ibm.com>
Applied.
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