Messages in this thread | | | Date | Thu, 19 May 2011 00:14:26 -0400 (EDT) | Subject | Re: [PATCH] tcp: Implement a two-level initial RTO as per draft RFC 2988bis-02. | From | David Miller <> |
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From: tsuna <tsunanet@gmail.com> Date: Wed, 18 May 2011 20:56:33 -0700
> On Wed, May 18, 2011 at 7:36 PM, David Miller <davem@davemloft.net> wrote: >> From: Benoit Sigoure <tsunanet@gmail.com> >> Date: Wed, 18 May 2011 19:22:24 -0700 >> >>> Prior to this patch, Linux would always use 3 seconds (compile-time >>> constant) as the initial RTO. Draft RFC 2988bis-02 proposes to tune >>> this down to 1 second and, in case of a timeout during the TCP 3WHS, >>> revert the RTO back up to 3 seconds when data transmission begins. >> >> We just had a discussion where it was determined that changes to >> these settings are "network specific" and therefore that if it >> is appropriate at all (I'm still not convinced) it is only suitable >> as a routing metric. > > Fair enough. I'll take another stab at it and see if I can change > this to be on a per network basis. Do I need any patch that's not yet > in Linus' tree? I'm referring to this:
Keep in mind another thing I do not like about this knob.
The IETF draft has a requirement that we fallback to 3 seconds if the initial RTO is 1 second.
Nothing in your facilities ensure this, or provide a way for the kernel to make sure this is the case.
And for other values of initial RTO, what fallback is appropriate?
As a result of all of this, I do not really think this is something the user should control at all.
I really would rather see the initial RTO be static and be set to 1 with fallback RTO of 3. -- 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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