[PATCH v2 net-next 08/18] net: move dev_tx_weight to net_hotdata

[Eric Dumazet <edumazet@google.com>]

dev_tx_weight is used in tx fast path.

Move it to net_hotdata for better cache locality.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
---
 include/linux/netdevice.h  | 1 -
 include/net/hotdata.h      | 1 +
 net/core/dev.c             | 1 -
 net/core/hotdata.c         | 1 +
 net/core/sysctl_net_core.c | 2 +-
 net/sched/sch_generic.c    | 3 ++-
 6 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 044d6f5b2ace3e2decd4296e01c8d3e200c6c7dc..c2a735edc44be95fbd4bbd1e234d883582bfde10 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -4788,7 +4788,6 @@ void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
 void dev_get_tstats64(struct net_device *dev, struct rtnl_link_stats64 *s);
 
 extern int		dev_rx_weight;
-extern int		dev_tx_weight;
 
 enum {
 	NESTED_SYNC_IMM_BIT,
diff --git a/include/net/hotdata.h b/include/net/hotdata.h
index d86d02f156fc350d508531d23b4fe06b2a27aca2..ffea9cc263e50e4eb69f4f60e2f10c256d9b633f 100644
--- a/include/net/hotdata.h
+++ b/include/net/hotdata.h
@@ -21,6 +21,7 @@ struct net_hotdata {
 	int			netdev_budget_usecs;
 	int			tstamp_prequeue;
 	int			max_backlog;
+	int			dev_tx_weight;
 };
 
 extern struct net_hotdata net_hotdata;
diff --git a/net/core/dev.c b/net/core/dev.c
index 1b112c4db983c2d7cd280bc8c2ebc621ea3c6145..3f8d451f42fb9ba621f1ea19e784c7f0be0bf2d8 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4409,7 +4409,6 @@ int weight_p __read_mostly = 64;           /* old backlog weight */
 int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
 int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
 int dev_rx_weight __read_mostly = 64;
-int dev_tx_weight __read_mostly = 64;
 
 /* Called with irq disabled */
 static inline void ____napi_schedule(struct softnet_data *sd,
diff --git a/net/core/hotdata.c b/net/core/hotdata.c
index 35ed5a83ecc7ebda513fe4fafc596e053f0252c5..ec8c3b48e8fea57491c5870055cffb44c779db44 100644
--- a/net/core/hotdata.c
+++ b/net/core/hotdata.c
@@ -16,5 +16,6 @@ struct net_hotdata net_hotdata __cacheline_aligned = {
 
 	.tstamp_prequeue = 1,
 	.max_backlog = 1000,
+	.dev_tx_weight = 64,
 };
 EXPORT_SYMBOL(net_hotdata);
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index 8eaeeb289914258f90cf940e906d5c6be0cc0cd6..a30016a8660e09db89b3153e4103c185a800a2ef 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -302,7 +302,7 @@ static int proc_do_dev_weight(struct ctl_table *table, int write,
 	if (!ret && write) {
 		weight = READ_ONCE(weight_p);
 		WRITE_ONCE(dev_rx_weight, weight * dev_weight_rx_bias);
-		WRITE_ONCE(dev_tx_weight, weight * dev_weight_tx_bias);
+		WRITE_ONCE(net_hotdata.dev_tx_weight, weight * dev_weight_tx_bias);
 	}
 	mutex_unlock(&dev_weight_mutex);
 
diff --git a/net/sched/sch_generic.c b/net/sched/sch_generic.c
index 9b3e9262040b6ef6516752c558c8997bf4054123..ff5336493777507242320d7e9214c637663f0734 100644
--- a/net/sched/sch_generic.c
+++ b/net/sched/sch_generic.c
@@ -27,6 +27,7 @@
 #include <net/sch_generic.h>
 #include <net/pkt_sched.h>
 #include <net/dst.h>
+#include <net/hotdata.h>
 #include <trace/events/qdisc.h>
 #include <trace/events/net.h>
 #include <net/xfrm.h>
@@ -409,7 +410,7 @@ static inline bool qdisc_restart(struct Qdisc *q, int *packets)
 
 void __qdisc_run(struct Qdisc *q)
 {
-	int quota = READ_ONCE(dev_tx_weight);
+	int quota = READ_ONCE(net_hotdata.dev_tx_weight);
 	int packets;
 
 	while (qdisc_restart(q, &packets)) {
-- 
2.44.0.278.ge034bb2e1d-goog