netdev - Re: txqueuelen has wrong units; should be time

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: <AANLkTinyE10wtM_xJsufT_3s3hvti7CN+9nyqScWa6SA@mail.gmail.com>
Date:	Sun, 27 Feb 2011 03:27:45 -0500
From:	Albert Cahalan <acahalan@...il.com>
To:	Eric Dumazet <eric.dumazet@...il.com>
Cc:	Mikael Abrahamsson <swmike@....pp.se>,
	linux-kernel <linux-kernel@...r.kernel.org>,
	netdev@...r.kernel.org
Subject: Re: txqueuelen has wrong units; should be time

On Sun, Feb 27, 2011 at 2:54 AM, Eric Dumazet <eric.dumazet@...il.com> wrote:
> Le dimanche 27 février 2011 à 08:02 +0100, Mikael Abrahamsson a écrit :
>> On Sun, 27 Feb 2011, Albert Cahalan wrote:
>>
>> > Nanoseconds seems fine; it's unlikely you'd ever want
>> > more than 4.2 seconds (32-bit unsigned) of queue.
...
> Problem is some machines have slow High Resolution timing services.
>
> _If_ we have a time limit, it will probably use the low resolution (aka
> jiffies), unless high resolution services are cheap.

As long as that is totally internal to the kernel and never
getting exposed by some API for setting the amount, sure.

> I was thinking not having an absolute hard limit, but an EWMA based one.

The whole point is to prevent stale packets, especially to prevent
them from messing with TCP, so I really don't think so. I suppose
you do get this to some extent via early drop.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html