openwrt/target/linux/generic/hack-4.14/662-remove_pfifo_fast.patch

From b531d492d5ef1cf9dba0f4888eb5fd8624a6d762 Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 7 Jul 2017 17:23:42 +0200
Subject: net: sched: switch default qdisc from pfifo_fast to fq_codel and remove pfifo_fast

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 net/sched/sch_generic.c | 140 ------------------------------------------------
 1 file changed, 140 deletions(-)

--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -453,146 +453,6 @@ struct Qdisc_ops noqueue_qdisc_ops __rea
 	.owner		=	THIS_MODULE,
 };
 
-static const u8 prio2band[TC_PRIO_MAX + 1] = {
-	1, 2, 2, 2, 1, 2, 0, 0 , 1, 1, 1, 1, 1, 1, 1, 1
-};
-
-/* 3-band FIFO queue: old style, but should be a bit faster than
-   generic prio+fifo combination.
- */
-
-#define PFIFO_FAST_BANDS 3
-
-/*
- * Private data for a pfifo_fast scheduler containing:
- * 	- queues for the three band
- * 	- bitmap indicating which of the bands contain skbs
- */
-struct pfifo_fast_priv {
-	u32 bitmap;
-	struct qdisc_skb_head q[PFIFO_FAST_BANDS];
-};
-
-/*
- * Convert a bitmap to the first band number where an skb is queued, where:
- * 	bitmap=0 means there are no skbs on any band.
- * 	bitmap=1 means there is an skb on band 0.
- *	bitmap=7 means there are skbs on all 3 bands, etc.
- */
-static const int bitmap2band[] = {-1, 0, 1, 0, 2, 0, 1, 0};
-
-static inline struct qdisc_skb_head *band2list(struct pfifo_fast_priv *priv,
-					     int band)
-{
-	return priv->q + band;
-}
-
-static int pfifo_fast_enqueue(struct sk_buff *skb, struct Qdisc *qdisc,
-			      struct sk_buff **to_free)
-{
-	if (qdisc->q.qlen < qdisc_dev(qdisc)->tx_queue_len) {
-		int band = prio2band[skb->priority & TC_PRIO_MAX];
-		struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-		struct qdisc_skb_head *list = band2list(priv, band);
-
-		priv->bitmap |= (1 << band);
-		qdisc->q.qlen++;
-		return __qdisc_enqueue_tail(skb, qdisc, list);
-	}
-
-	return qdisc_drop(skb, qdisc, to_free);
-}
-
-static struct sk_buff *pfifo_fast_dequeue(struct Qdisc *qdisc)
-{
-	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-	int band = bitmap2band[priv->bitmap];
-
-	if (likely(band >= 0)) {
-		struct qdisc_skb_head *qh = band2list(priv, band);
-		struct sk_buff *skb = __qdisc_dequeue_head(qh);
-
-		if (likely(skb != NULL)) {
-			qdisc_qstats_backlog_dec(qdisc, skb);
-			qdisc_bstats_update(qdisc, skb);
-		}
-
-		qdisc->q.qlen--;
-		if (qh->qlen == 0)
-			priv->bitmap &= ~(1 << band);
-
-		return skb;
-	}
-
-	return NULL;
-}
-
-static struct sk_buff *pfifo_fast_peek(struct Qdisc *qdisc)
-{
-	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-	int band = bitmap2band[priv->bitmap];
-
-	if (band >= 0) {
-		struct qdisc_skb_head *qh = band2list(priv, band);
-
-		return qh->head;
-	}
-
-	return NULL;
-}
-
-static void pfifo_fast_reset(struct Qdisc *qdisc)
-{
-	int prio;
-	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-
-	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
-		__qdisc_reset_queue(band2list(priv, prio));
-
-	priv->bitmap = 0;
-	qdisc->qstats.backlog = 0;
-	qdisc->q.qlen = 0;
-}
-
-static int pfifo_fast_dump(struct Qdisc *qdisc, struct sk_buff *skb)
-{
-	struct tc_prio_qopt opt = { .bands = PFIFO_FAST_BANDS };
-
-	memcpy(&opt.priomap, prio2band, TC_PRIO_MAX + 1);
-	if (nla_put(skb, TCA_OPTIONS, sizeof(opt), &opt))
-		goto nla_put_failure;
-	return skb->len;
-
-nla_put_failure:
-	return -1;
-}
-
-static int pfifo_fast_init(struct Qdisc *qdisc, struct nlattr *opt)
-{
-	int prio;
-	struct pfifo_fast_priv *priv = qdisc_priv(qdisc);
-
-	for (prio = 0; prio < PFIFO_FAST_BANDS; prio++)
-		qdisc_skb_head_init(band2list(priv, prio));
-
-	/* Can by-pass the queue discipline */
-	qdisc->flags |= TCQ_F_CAN_BYPASS;
-	return 0;
-}
-
-struct Qdisc_ops pfifo_fast_ops __read_mostly = {
-	.id		=	"pfifo_fast",
-	.priv_size	=	sizeof(struct pfifo_fast_priv),
-	.enqueue	=	pfifo_fast_enqueue,
-	.dequeue	=	pfifo_fast_dequeue,
-	.peek		=	pfifo_fast_peek,
-	.init		=	pfifo_fast_init,
-	.reset		=	pfifo_fast_reset,
-	.dump		=	pfifo_fast_dump,
-	.owner		=	THIS_MODULE,
-};
-EXPORT_SYMBOL(pfifo_fast_ops);
-
 static struct lock_class_key qdisc_tx_busylock;
 static struct lock_class_key qdisc_running_key;