Subject: Re: why does skb->tstamp use getnstimeofday?

From: Rick Jones <[email-masked]>
Date: Mon, 16 Jan 2012 14:05:21 -0800

On 01/15/2012 09:55 AM, Anatoly Sivov wrote:
> I missed that field tstamp is used for things other than RTT and can be
> even user-spaced with SO_TIMESTAMP.
> However, timekeeper speed up/slow down (due to ntp) can seriously affect
> some congestion avoidance algorithm quality, I guess.
> Am I wrong?

Good question - not sure if we will see anything, but the upcoming 
leap-second might be interesting to watch - though I think contemporary 
NTP addresses that by a big slew rather than a step adjust.  Of course 
it can step-adjust the time on the system, but 99 times out of 10 (*) 
that will be just at system start-up, when there probably will not be 
all that many congestion controlled connections active.  Of course, who 
knows what that 100th out of 10 times will do.

rick jones
* 99 times out of 10 is an expression which if I recall correctly was 
coined or at least repeated by a high-school sports coach to mean 
"virtually all of the time"