netdev - Re: [PATCH net-next v2 1/6] tcp: instrument tcp sender limits chronographs

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CADVnQy=xJCneqv7YL+1C8kOUuZB9pEGYrAOSyih1xTN_NbqwtA@mail.gmail.com>
Date:   Mon, 28 Nov 2016 12:23:14 -0500
From:   Neal Cardwell <ncardwell@...gle.com>
To:     Yuchung Cheng <ycheng@...gle.com>
Cc:     David Miller <davem@...emloft.net>,
        Soheil Hassas Yeganeh <soheil@...gle.com>,
        francisyyan@...il.com, Netdev <netdev@...r.kernel.org>,
        Eric Dumazet <edumazet@...gle.com>
Subject: Re: [PATCH net-next v2 1/6] tcp: instrument tcp sender limits chronographs

On Mon, Nov 28, 2016 at 2:07 AM, Yuchung Cheng <ycheng@...gle.com> wrote:
> From: Francis Yan <francisyyan@...il.com>
>
> This patch implements the skeleton of the TCP chronograph
> instrumentation on sender side limits:
>
>         1) idle (unspec)
>         2) busy sending data other than 3-4 below
>         3) rwnd-limited
>         4) sndbuf-limited
>
> The limits are enumerated 'tcp_chrono'. Since a connection in
> theory can idle forever, we do not track the actual length of this
> uninteresting idle period. For the rest we track how long the sender
> spends in each limit. At any point during the life time of a
> connection, the sender must be in one of the four states.
>
> If there are multiple conditions worthy of tracking in a chronograph
> then the highest priority enum takes precedence over
> the other conditions. So that if something "more interesting"
> starts happening, stop the previous chrono and start a new one.
>
> The time unit is jiffy(u32) in order to save space in tcp_sock.
> This implies application must sample the stats no longer than every
> 49 days of 1ms jiffy.
>
> Signed-off-by: Francis Yan <francisyyan@...il.com>
> Signed-off-by: Yuchung Cheng <ycheng@...gle.com>
> Signed-off-by: Soheil Hassas Yeganeh <soheil@...gle.com>
> ---

Acked-by: Neal Cardwell <ncardwell@...gle.com>

neal