netdev - Re: [RFC net-next 0/5] TSN: Add qdisc-based config interfaces for traffic shapers

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: <20171019203949.pyv44i5sy6lnuavh@localhost>
Date:   Thu, 19 Oct 2017 13:39:49 -0700
From:   Richard Cochran <richardcochran@...il.com>
To:     Jesus Sanchez-Palencia <jesus.sanchez-palencia@...el.com>
Cc:     Vinicius Costa Gomes <vinicius.gomes@...el.com>,
        netdev@...r.kernel.org, jhs@...atatu.com, xiyou.wangcong@...il.com,
        jiri@...nulli.us, intel-wired-lan@...ts.osuosl.org,
        andre.guedes@...el.com, ivan.briano@...el.com,
        boon.leong.ong@...el.com, Levi Pearson <levipearson@...il.com>,
        Henrik Austad <henrik@...tad.us>
Subject: Re: [RFC net-next 0/5] TSN: Add qdisc-based config interfaces for
 traffic shapers

On Wed, Oct 18, 2017 at 03:37:35PM -0700, Jesus Sanchez-Palencia wrote:
> I also did some tests with when you don't set valid launch times, but here using
> your idea from above, so with the driver calculating a valid launch time (i.e.
> current NIC time + X ns, varying X across tests) for packets that didn't have it
> set by the user, and I wasn't too happy with its reliability. It could
> definitely be improved, but it has left me wondering: instead, what about
> documenting that if you enable TXTIME, then you *must* provide a valid Launch
> time for all packets on traffic classes that are affected?

If txtime is enabled, then CBS is pointless because the txtime already
specifies the bandwidth implicitly.

The problem is when one program uses txtime and another uses CBS, then
the CBS user will experience really wrong performance.

Thanks,
Richard