From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Dumazet <eric.dumazet@gmail.com>
Subject: Re: [PATCH 3/4] sch_api: Allow reducing queue backlog by a negative
 value
Date: Mon, 7 Jan 2019 12:54:22 -0800
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 <20190107194733.31138-4-toke@toke.dk>
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On 01/07/2019 11:47 AM, Toke Høiland-Jørgensen wrote:
> From: Toke Høiland-Jørgensen <toke@redhat.com>
> 
> With GSO splitting in sch_cake, we can decrease as well as increase the
> qlen. To make it possible to signal this up the qdisc tree, change
> qdisc_tree_reduce_backlog() to accept signed integer values as the number
> of packets and bytes to reduce the backlog by.


Not sure why this patch is needed, given we use u32 integers
for q.qlen & qstats.backlog

0xFFFFFFFF for n is really -1 once folded...

sch->q.qlen -= n;
sch->qstats.backlog -= len;