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

[Jonathan Maxwell]

On Tue, Jul 10, 2018 at 10:48 PM, Eric Dumazet <eric.dumazet@xxxxxxxxx> wrote:
>
>
> On 07/10/2018 05:38 AM, Eric Dumazet wrote:
>
>> 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.