On Wed, 31 Oct 2007 22:42:57 +0800 Herbert Xu <[EMAIL PROTECTED]> wrote:
> On Wed, Oct 31, 2007 at 11:05:45PM +0900, Mitsuru Chinen wrote: > > > > > > 1. udp6InDatagrams is incremented instead of udpInErrors > > > > 2. In userland, recvfrom() replies an error with EAGAIN. > > > > recvfrom() wasn't aware of such a packet before. > > > > > > > > Are these changes intentional? > > > > As far as I tested, this doesn't happen with the old code even if > > a filter is attached. However, this happen with the new code > > without a filter and I don't see this rather when a filter is > > attached. So, I'm afraid it's new. > > Sorry, I read the patch the wrong way around :) > > 1) is just an accounting issue. It shouldn't be too difficult > to fix it up. In fact, I think udpInErrors will still be > incremented once we detect the error. > > 2) shouldn't be an issue because we've already solved the > problem by making poll/select do the checksum verification > before indiciating that the socket is readable. > > > > And, we're not sure how much the "optimization"'s benefit is. > > > It is even worse when we are hand > > The checksum verification is costly because we have to bring > the payload into cache. Since filters are very rare it's > worthwhile to postpone the checksum verification for the common > case. > > Also as a general rule, we want to avoid divergent behaviour > between IPv4 and IPv6. So for changes like this we should > really modify both stacks in future rather than have each > stack do its own thing. I got it. OK. I will submit a patch to postpone the udpInError counter incrementation, either. Thanks for your detailed explanation! Best Regards, ---- Mitsuru Chinen <[EMAIL PROTECTED]> - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
