Re: [PATCH net] tcp: fix wraparound issue in tcp_lp

On Mon, 2017-05-01 at 18:04 -0700, Eric Dumazet wrote:

Simply to not perform (tcp_time_stamp - tp->rx_opt.rcv_tsecr) twice.

jiffies being volatile, this can not be optimized by the compiler.

I have a patch series (for linux-4.13) that will switch TCP stack to 1ms
TS options, regardless of CONFIG_HZ value, and when cooking it I found
this bug.

I forgot to say that after this upcoming patch series, tcp_time_stamp
will become a more expensive function, no longer a plain (u32)jiffies.