Re: txqueuelen has wrong units; should be time

From: Albert Cahalan
Date: Sun Feb 27 2011 - 03:27:55 EST


On Sun, Feb 27, 2011 at 2:54 AM, Eric Dumazet <eric.dumazet@xxxxxxxxx> 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 linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/