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net: make struct net_device::tx_queue_len unsigned int

PATCH Applied Alexey Dobriyan 2 participants 2 messages May 17, 2017 – May 18, 2017

Subsystems (3)
Networking Network drivers Generic hdlc (wan) drivers
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Alexey Dobriyan

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#0 lore raw

PATCH 1/1 net: make struct net_device::tx_queue_len unsigned int

4 billion packet queue is something unthinkable so use 32-bit value for now.

Space savings on x86_64:

add/remove: 0/0 grow/shrink: 3/70 up/down: 16/-131 (-115)
function old new delta
change_tx_queue_len 94 108 +14
qdisc_create 1176 1177 +1
alloc_netdev_mqs 1124 1125 +1
xenvif_alloc 533 532 -1
x25_asy_setup 167 166 -1
...
tun_queue_resize 945 940 -5
pfifo_fast_enqueue 167 162 -5
qfq_init_qdisc 168 158 -10
tap_queue_resize 810 799 -11
transmit 719 698 -21

Signed-off-by Alexey Dobriyan <[email protected]>

---

 drivers/net/wan/hdlc_raw_eth.c |    3 ++-
 include/linux/netdevice.h      |    2 +-
 net/core/net-sysfs.c           |    8 ++++++--
 net/core/rtnetlink.c           |    4 ++--
 4 files changed, 11 insertions(+), 6 deletions(-)
drivers/net/wan/hdlc_raw_eth.c +2 -1
@@ -57,7 +57,8 @@ static int raw_eth_ioctl(struct net_device *dev, struct ifreq *ifr)
 	const size_t size = sizeof(raw_hdlc_proto);
 	raw_hdlc_proto new_settings;
 	hdlc_device *hdlc = dev_to_hdlc(dev);
-	int result, old_qlen;
+	unsigned int old_qlen;
+	int result;
 
 	switch (ifr->ifr_settings.type) {
 	case IF_GET_PROTO:
include/linux/netdevice.h +1 -1
@@ -1824,7 +1824,7 @@ struct net_device {
 #ifdef CONFIG_NET_SCHED
 	DECLARE_HASHTABLE	(qdisc_hash, 4);
 #endif
-	unsigned long		tx_queue_len;
+	unsigned int		tx_queue_len;
 	spinlock_t		tx_global_lock;
 	int			watchdog_timeo;
net/core/net-sysfs.c +6 -2
@@ -323,7 +323,11 @@ NETDEVICE_SHOW_RW(flags, fmt_hex);
 
 static int change_tx_queue_len(struct net_device *dev, unsigned long new_len)
 {
-	int res, orig_len = dev->tx_queue_len;
+	unsigned int orig_len = dev->tx_queue_len;
+	int res;
+
+	if (new_len != (unsigned int)new_len)
+		return -ERANGE;
 
 	if (new_len != orig_len) {
 		dev->tx_queue_len = new_len;

@@ -349,7 +353,7 @@ static ssize_t tx_queue_len_store(struct device *dev,
 
 	return netdev_store(dev, attr, buf, len, change_tx_queue_len);
 }
-NETDEVICE_SHOW_RW(tx_queue_len, fmt_ulong);
+NETDEVICE_SHOW_RW(tx_queue_len, fmt_dec);
 
 static int change_gro_flush_timeout(struct net_device *dev, unsigned long val)
 {
net/core/rtnetlink.c +2 -2
@@ -2046,8 +2046,8 @@ static int do_setlink(const struct sk_buff *skb,
 	}
 
 	if (tb[IFLA_TXQLEN]) {
-		unsigned long value = nla_get_u32(tb[IFLA_TXQLEN]);
-		unsigned long orig_len = dev->tx_queue_len;
+		unsigned int value = nla_get_u32(tb[IFLA_TXQLEN]);
+		unsigned int orig_len = dev->tx_queue_len;
 
 		if (dev->tx_queue_len ^ value) {
 			dev->tx_queue_len = value;
maintainer Applied
#1 lore raw

From: Alexey Dobriyan <[email protected]>
Date: Wed, 17 May 2017 13:30:44 +0300

Quoted 19 lines

4 billion packet queue is something unthinkable so use 32-bit value for now.

Space savings on x86_64:

add/remove: 0/0 grow/shrink: 3/70 up/down: 16/-131 (-115)
function old new delta
change_tx_queue_len 94 108 +14
qdisc_create 1176 1177 +1
alloc_netdev_mqs 1124 1125 +1
xenvif_alloc 533 532 -1
x25_asy_setup 167 166 -1
...
tun_queue_resize 945 940 -5
pfifo_fast_enqueue 167 162 -5
qfq_init_qdisc 168 158 -10
tap_queue_resize 810 799 -11
transmit 719 698 -21

Quoted 1 line
Signed-off-by Alexey Dobriyan <[email protected]>

Applied.