[Cake] Dropping dropped

[Adrian Popescu <adriannnpopescu@gmail.com>]

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Hello,

I've taken a look at cake's source code to see what simple changes could be
made to attempt to speed it up. There seemed to be a per flow variable
called dropped which might not be that useful for regular users. The
attached patch removes it.

Perhaps cake could be optimized further for slow devices. What's the
recommended solution for profiling the kernel on mips with openwrt?

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diff --git a/sch_cake.c b/sch_cake.c
index 3a26db0..d1ea1d6 100644
--- a/sch_cake.c
+++ b/sch_cake.c
@@ -136,7 +136,6 @@ struct cake_flow {
 	struct sk_buff	  *tail;
 	struct list_head  flowchain;
 	s32		  deficit;
-	u32		  dropped;
 	struct cobalt_vars cvars;
 	u16		  srchost; /* index into cake_host table */
 	u16		  dsthost;
@@ -1594,7 +1593,6 @@ static unsigned int cake_drop(struct Qdisc *sch, struct sk_buff **to_free)
 	sch->qstats.backlog -= len;
 	qdisc_tree_reduce_backlog(sch, 1, len);
 
-	flow->dropped++;
 	b->tin_dropped++;
 	sch->qstats.drops++;
 
@@ -2191,7 +2189,6 @@ retry:
 			flow->deficit -= len;
 			b->tin_deficit -= len;
 		}
-		flow->dropped++;
 		b->tin_dropped++;
 		qdisc_tree_reduce_backlog(sch, 1, qdisc_pkt_len(skb));
 #if LINUX_VERSION_CODE < KERNEL_VERSION(4, 8, 0)
@@ -3088,7 +3085,6 @@ static int cake_dump_class_stats(struct Qdisc *sch, unsigned long cl,
 			cake_maybe_unlock(sch);
 		}
 		qs.backlog = b->backlogs[idx % CAKE_QUEUES];
-		qs.drops = flow->dropped;
 	}
 	if (gnet_stats_copy_queue(d, NULL, &qs, qs.qlen) < 0)
 		return -1;