From: Eric Dumazet <eric.dumazet@gmail.com>
To: David Miller <davem@davemloft.net>
Cc: netdev <netdev@vger.kernel.org>,
Hagen Paul Pfeifer <hagen@jauu.net>,
Yuchung Cheng <ycheng@google.com>,
Andreas Terzis <aterzis@google.com>, Mark Gordon <msg@google.com>
Subject: Re: [PATCH] netem: fix rate extension and drop accounting
Date: Tue, 03 Jul 2012 11:54:17 +0200 [thread overview]
Message-ID: <1341309257.2583.153.camel@edumazet-glaptop> (raw)
In-Reply-To: <1341307524.2583.115.camel@edumazet-glaptop>
On Tue, 2012-07-03 at 11:25 +0200, Eric Dumazet wrote:
> From: Eric Dumazet <edumazet@google.com>
>
> commit 7bc0f28c7a0c (netem: rate extension) did wrong maths when packet
> is enqueued while queue is not empty.
>
> Result is unexpected cumulative delays
>
> # tc qd add dev eth0 root est 1sec 4sec netem delay 200ms rate 100kbit
> # ping -i 0.1 172.30.42.18
> PING 172.30.42.18 (172.30.42.18) 56(84) bytes of data.
> 64 bytes from 172.30.42.18: icmp_req=1 ttl=64 time=208 ms
> 64 bytes from 172.30.42.18: icmp_req=2 ttl=64 time=424 ms
> 64 bytes from 172.30.42.18: icmp_req=3 ttl=64 time=838 ms
> 64 bytes from 172.30.42.18: icmp_req=4 ttl=64 time=1142 ms
> 64 bytes from 172.30.42.18: icmp_req=5 ttl=64 time=1335 ms
> 64 bytes from 172.30.42.18: icmp_req=6 ttl=64 time=1949 ms
> 64 bytes from 172.30.42.18: icmp_req=7 ttl=64 time=2450 ms
> 64 bytes from 172.30.42.18: icmp_req=8 ttl=64 time=2840 ms
> 64 bytes from 172.30.42.18: icmp_req=9 ttl=64 time=3121 ms
> 64 bytes from 172.30.42.18: icmp_req=10 ttl=64 time=3291 ms
> 64 bytes from 172.30.42.18: icmp_req=11 ttl=64 time=3784 ms
>
> This patch also fixes a double drop accounting in case packet is dropped
> in tfifo_enqueue()
>
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Yuchung Cheng <ycheng@google.com>
> Cc: Andreas Terzis <aterzis@google.com>
> Cc: Mark Gordon <msg@google.com>
> Cc: Hagen Paul Pfeifer <hagen@jauu.net>
> ---
Hmm, I'll send a v2
next prev parent reply other threads:[~2012-07-03 9:54 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 [this message]
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
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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