>>> On 08.07.13 at 17:22, Eric Dumazet <[email protected]> wrote: > On Mon, 2013-07-08 at 15:20 +0100, Jan Beulich wrote: > >> Okay, so with that done (see below) Dion is now seeing the >> WARN_ON_ONCE(delta < len) in skb_try_coalesce() triggering. Of >> course, with it having crashed before, it's hard to tell whether the >> triggering now is an effect of the patch, or just got unmasked by it. > > Please note this warning is not the sign of an error.
Thanks for pointing this out. > It can be triggered because network stack (IP + TCP) had to reallocate > skb->head to hold all the headers. > > pskb_may_pull() doesn't change skb->truesize, for various reasons, so we > can have a situation where the warning triggers. > > For example, it can happen when drivers use a really small skb->head, > like 64 bytes, as its not big enough to hold ethernet+IP+TCP headers. We know from the crashes prior to the patch here that this is exactly what is happening. Jan -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
