Messages in this thread | | | Date | Thu, 23 Aug 2012 15:57:09 -0500 | From | Larry Finger <> | Subject | Re: Regression associated with commit c8628155ece3 - "tcp: reduce out_of_order memory use" |
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On 08/22/2012 11:03 PM, Eric Dumazet wrote: > > Changing the allocation size removes the problem ? thats really strange. > > If you try different sizes in the 9100-30720 range, can you pinpoint the > failure threshold ?
The allocation size change did not fix the problem. It turned out that 10 tries from a secure web page were not enough to trigger this intermittent problem that particular test.
Based on DaveM's comment that skb->truesize could be wrong, I tried setting truesize after every netdev_alloc_skb() call. Of course, that had no effect. I then found https://lkml.org/lkml/2010/11/19/505I, which clearly states why this need not be done.
What skb modifications require that truesize be adjusted? The driver never resets skb->len or skb->data_len for any buffers, other than setting skb->len to zero.
Thanks,
Larry
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