Re: [net-next,v3] tcp: Improve setsockopt() TCP_USER_TIMEOUT accuracy

On Tue, Jul 10, 2018 at 10:48 PM, Eric Dumazet [off-list ref] wrote:

On 07/10/2018 05:38 AM, Eric Dumazet wrote:

quoted

Note that if we always do jiffies_to_msecs(icsk->icsk_user_timeout) in TCP,
we also could change the convention and store msecs in this field instead of jiffies.

That would eliminate the msecs_to_jiffies() and jiffies_to_msecs() dance.

(That would be done in a patch of its own, of course)

tcp_keepalive_timer() does use icsk->icsk_user_timeout directly in jiffies unit,
but considering keeapalive timers are rarely used, this point would have to
do the msecs_to_jiffies() conversion.

and also if icsk->icsk_user_timeout = 0, then timeout in retransmits_timed_out()
is in jiffies and that would need to addressed.