Thread (9 messages) 9 messages, 4 authors, 2021-04-29

Re: [PATCH net] openvswitch: meter: remove rate from the bucket size calculation

From: Jean Tourrilhes <hidden>
Date: 2021-04-28 17:18:45
Also in: lkml

On Wed, Apr 28, 2021 at 01:22:12PM +0200, Ilya Maximets wrote:
I didn't test it, but I looked at the implementation in
net/sched/act_police.c and net/sched/sch_tbf.c, and they should work
in a same way as this patch, i.e. it's a classic token bucket where
burst is a burst and nothing else.
	Actually, act_police.c and sch_tbf.c will behave completely
differently, even if they are both based on the token bucket
algorithm.
	The reason is that sch_tbf.c is applied to a queue, and the
queue will smooth out traffic and avoid drops. The token bucket is
used to dequeue the queue, this is sometime called leaky bucket. I've
personally used sch_tbf.c with burst size barely bigger than the MTU,
and it works fine.
	This is why I was suggesting to compare to act_police.c, which
does not have a queue to smooth out traffic and can only drop
packets.
	I believe OVS meters are similar to policers, so that's why
they are suprising for people used to queues such as TBF and HTB.

	Regards,

	Jean
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help