netdev - RE: [patch net-next 2/3] net/sched: Change cls

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Date:   Tue, 29 Aug 2017 01:34:23 +0000
From:   Chris Mi <chrism@...lanox.com>
To:     Jamal Hadi Salim <jhs@...atatu.com>,
        "netdev@...r.kernel.org" <netdev@...r.kernel.org>
CC:     "xiyou.wangcong@...il.com" <xiyou.wangcong@...il.com>,
        "jiri@...nulli.us" <jiri@...nulli.us>,
        "davem@...emloft.net" <davem@...emloft.net>,
        "mawilcox@...rosoft.com" <mawilcox@...rosoft.com>
Subject: RE: [patch net-next 2/3] net/sched: Change cls_flower to use IDR

> -----Original Message-----
> From: Jamal Hadi Salim [mailto:jhs@...atatu.com]
> Sent: Tuesday, August 29, 2017 5:56 AM
> To: Chris Mi <chrism@...lanox.com>; netdev@...r.kernel.org
> Cc: xiyou.wangcong@...il.com; jiri@...nulli.us; davem@...emloft.net;
> mawilcox@...rosoft.com
> Subject: Re: [patch net-next 2/3] net/sched: Change cls_flower to use IDR
> 
> On 17-08-28 02:41 AM, Chris Mi wrote:
> > Currently, all filters with the same priority are linked in a doubly
> > linked list. Every filter should have a unique handle. To make the
> > handle unique, we need to iterate the list every time to see if the
> > handle exists or not when inserting a new filter. It is time-consuming.
> > For example, it takes about 5m3.169s to insert 64K rules.
> >
> > This patch changes cls_flower to use IDR. With this patch, it takes
> > about 0m1.127s to insert 64K rules. The improvement is huge.
> >
> > But please note that in this testing, all filters share the same action.
> > If every filter has a unique action, that is another bottleneck.
> > Follow-up patch in this patchset addresses that.
> >
> > Signed-off-by: Chris Mi <chrism@...lanox.com>
> > Signed-off-by: Jiri Pirko <jiri@...lanox.com>
> 
> Acked-by: Jamal Hadi Salim <jhs@...atatu.com>
> 
> As Cong asked last time - any plans to add to other classifiers?
I think if other classifiers don't need so many items, list is enough for them.
If we change all of them, we need spend a lot of time to test them to make sure
there is no regression. But the benefit is not very big. If a certain classifier
need to change in the future, flower is an example for reference.

-Chris
> 
> cheers,
> jamal