From: David S. Miller Date: Wed, 17 May 2017 20:06:03 +0000 (-0400) Subject: Merge branch 'tcp-TCP-TS-option-use-1-ms-clock' X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e26925ec03b31f5ae4c1fc544515486229334ef9;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git Merge branch 'tcp-TCP-TS-option-use-1-ms-clock' Eric Dumazet says: ==================== tcp: TCP TS option use 1 ms clock TCP Timestamps option is defined in RFC 7323 Traditionally on linux, it has been tied to the internal 'jiffy' variable, because it had been a cheap and good enough generator. Unfortunately some distros use HZ=250 or even HZ=100 leading to not very useful TCP timestamps. For TCP flows in the DC, Google has used usec resolution for more than two years with great success [1]. RCVBUF autotuning is more precise. This series converts tp->tcp_mstamp to a plain u64 value storing a 1 usec TCP clock. This choice will allow us to upstream the 1 usec TS option as discussed in IETF 97. Kathleen Nichols [2] and others advocate for 1ms TS clocks for network analysis. (1ms being the lowest value supported by RFC 7323.) [1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf [2] http://netseminar.stanford.edu/seminars/02_02_17.pdf ==================== Signed-off-by: David S. Miller --- e26925ec03b31f5ae4c1fc544515486229334ef9