Hello,
I was wondering what queues/buffers does netem use and how does one control or monitor them?
I could not find this information anywhere and I am not that good in reading the sources to be able to tell enough about this :) If we talk only about the situation where netem is the root qdisc for a particular interface, I would imagine it might be using the txqueue of that interface, but I am not sure if that's really the case...
Thanks,
Petr MOTEJLEK
Hello Hagen,
Could you please give me some example of such a tc command that would tell me the statistics? I am not sure what you mean.
Is there a way I can manipulate the internal rbtree queue size, please?
Thank you
Petr MOTEJLEK
________________________________________
From: Hagen Paul Pfeifer <redacted>
Sent: Thursday, July 16, 2015 2:42 PM
To: netdev@vger.kernel.org; Motejlek, Petr
Cc: netem@osdl.org
Subject: Re: What queues/buffers does tc-netem use?
On July 16, 2015 at 1:28 PM "Motejlek, Petr" [off-list ref]
wrote:
I was wondering what queues/buffers does netem use and how does one
control or monitor them?
netem uses his own rbtree based queue. You can use tc(1) to get
statistics.
I could not find this information anywhere and I am not that good in
reading the sources to be able to tell enough about this :) If we talk
only about the situation where netem is the root qdisc for a particular
interface, I would imagine it might be using the txqueue of that
interface, but I am not sure if that's really the case...
Saddly there is no netem implementation documentation, but the source code
is straightforward. You may take a look:
http://lxr.free-electrons.com/source/net/sched/sch_netem.c
Cheers, Hagen
On July 16, 2015 at 1:28 PM "Motejlek, Petr" [off-list ref]
wrote:
I was wondering what queues/buffers does netem use and how does one
control or monitor them?
netem uses his own rbtree based queue. You can use tc(1) to get
statistics.
I could not find this information anywhere and I am not that good in
reading the sources to be able to tell enough about this :) If we talk
only about the situation where netem is the root qdisc for a particular
interface, I would imagine it might be using the txqueue of that
interface, but I am not sure if that's really the case...
Saddly there is no netem implementation documentation, but the source code
is straightforward. You may take a look:
http://lxr.free-electrons.com/source/net/sched/sch_netem.c
Cheers, Hagen
On July 16, 2015 at 2:48 PM "Motejlek, Petr" [off-list ref]
wrote:
Could you please give me some example of such a tc command that
would tell me the statistics? I am not sure what you mean.
tc -s qdisc show dev eth0
Is there a way I can manipulate the internal rbtree queue size, please?
Sure, the option is called limit.
Thank you
You are welcome!
Hagen