Messages in this thread | | | Date | Thu, 19 May 2011 19:01:53 -0700 | Subject | Re: [PATCH] tcp: Expose the initial RTO via a new sysctl. | From | "H.K. Jerry Chu" <> |
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On Wed, May 18, 2011 at 12:40 PM, tsuna <tsunanet@gmail.com> wrote: > On Wed, May 18, 2011 at 12:26 PM, David Miller <davem@davemloft.net> wrote: >> If you read the ietf draft that reduces the initial RTO down to 1 >> second, it states that if we take a timeout during the initial >> connection handshake then we have to revert the RTO back up to 3 >> seconds. >> >> This fallback logic conflicts with being able to only change the >> initial RTO via sysctl, I think. Because there are actually two >> values at stake and they depend upon eachother, the initial RTO and >> the value we fallback to on initial handshake retransmissions. >> >> So I'd rather get a patch that implements the 1 second initial >> RTO with the 3 second fallback on SYN retransmit, than this patch. >> >> We already have too many knobs. > > I was hoping this knob would be accepted because this is such an > important issue that it even warrants an IETF draft to attempt to > change the standard. I'm not sure how long it will take for this > draft to be accepted and then implemented, so I thought adding this > simple knob today would really help in the future.
As one of the co-authors of rfc2988bis I was planning to provide a patch as soon as the draft gets approved but it looks like you have beaten me to it :)
Personally I'm in favor of a knob too. We at Google has added such a knob for years.
Jerry
> > Plus, should the draft be accepted, this knob will still be just as > useful (e.g. to revert back to today's behavior), and people might > want to consider adding another knob for the fallback initRTO (this is > debatable). I don't believe this knob conflicts with the proposed > change to the standard, it actually goes along with it pretty well and > helps us prepare better for this upcoming change. > > I agree that there are too many knobs, and I hate feature creep too, > but I've found many of these knobs to be really useful, and the degree > to which Linux's TCP stack can be tuned is part of what makes it so > versatile. > > -- > Benoit "tsuna" Sigoure > Software Engineer @ www.StumbleUpon.com > -- > To unsubscribe from this list: send the line "unsubscribe netdev" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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