From: Hagen Paul Pfeifer <hagen@jauu.net>
To: Mark Gordon <msg@google.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>,
David Miller <davem@davemloft.net>,
netdev <netdev@vger.kernel.org>,
Yuchung Cheng <ycheng@google.com>,
Andreas Terzis <aterzis@google.com>
Subject: Re: [PATCH] netem: fix rate extension and drop accounting
Date: Tue, 17 Jul 2012 01:26:01 +0200 [thread overview]
Message-ID: <20120716232600.GI3415@nuttenaction> (raw)
In-Reply-To: <CAPVr9VP7DniPZj4vZi_myJWfL5JLYKYTXXtrXcKHo9LjEQzjYw@mail.gmail.com>
Sorry Eric for the delay! I am a little bit under project pressure. But I will
test patches where I can.
* Mark Gordon | 2012-07-16 15:15:07 [-0700]:
>Sorry for the late reply on this. I'm still pretty unsure about the math
>we're doing on
>
>delay -= netem_skb_cb(skb_peek(list))->time_to_send - now;
>
>First, shouldn't it be skb_peek_tail(list)? Even if you do that the math
The delta is between now and when the _next_ packet is to send. New packets
are enqueued on the tail.
>doesn't really seem to work out. In my mind there ought to be at least one
>more non-linearity. The code before/after this patch does not work as I
>would expect and seems to have fairly random effects on the bandwidth and
>that the below patch does work for me. Here is what I'm suggesting
>(relative to the new patches)
As Eric said: there are problems in combination with a static delay. During
rate extension development we tested the raw/vanilla "rate" functionality.
The rate part works faultless[TM] - at least independet of any other
"delay-latency generator".
Hagen
next prev parent reply other threads:[~2012-07-16 23:26 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-03 9:25 [PATCH] netem: fix rate extension and drop accounting Eric Dumazet
2012-07-03 9:54 ` Eric Dumazet
2012-07-03 22:04 ` Hagen Paul Pfeifer
2012-07-04 5:58 ` Eric Dumazet
2012-07-04 16:51 ` Hagen Paul Pfeifer
2012-07-04 17:23 ` Eric Dumazet
2012-07-04 17:30 ` Hagen Paul Pfeifer
[not found] ` <CAPVr9VP7DniPZj4vZi_myJWfL5JLYKYTXXtrXcKHo9LjEQzjYw@mail.gmail.com>
2012-07-16 23:26 ` Hagen Paul Pfeifer [this message]
2012-07-17 5:12 ` Eric Dumazet
[not found] ` <CAPVr9VMCYFO-7uEzO6ft2vpPhVvRgHB3EWJJG62OqGqux1LsZQ@mail.gmail.com>
2012-07-17 17:39 ` Eric Dumazet
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