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Kirill Smelkov
linux
Commits
567f4872
Commit
567f4872
authored
Jun 20, 2004
by
Arthur Kepner
Committed by
David S. Miller
Jun 20, 2004
Browse files
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Plain Diff
[NET]: Lockless loopback patch (version 2).
parent
e2580c9e
Changes
6
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Showing
6 changed files
with
108 additions
and
37 deletions
+108
-37
drivers/net/loopback.c
drivers/net/loopback.c
+33
-8
include/linux/netdevice.h
include/linux/netdevice.h
+1
-0
include/net/pkt_sched.h
include/net/pkt_sched.h
+2
-0
net/core/dev.c
net/core/dev.c
+40
-15
net/sched/sch_api.c
net/sched/sch_api.c
+3
-0
net/sched/sch_generic.c
net/sched/sch_generic.c
+29
-14
No files found.
drivers/net/loopback.c
View file @
567f4872
...
...
@@ -56,6 +56,7 @@
#include <linux/ip.h>
#include <linux/tcp.h>
static
struct
net_device_stats
*
loopback_stats
;
#define LOOPBACK_OVERHEAD (128 + MAX_HEADER + 16 + 16)
...
...
@@ -123,7 +124,6 @@ static void emulate_large_send_offload(struct sk_buff *skb)
*/
static
int
loopback_xmit
(
struct
sk_buff
*
skb
,
struct
net_device
*
dev
)
{
struct
net_device_stats
*
stats
=
dev
->
priv
;
skb_orphan
(
skb
);
...
...
@@ -142,11 +142,12 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
}
dev
->
last_rx
=
jiffies
;
if
(
likely
(
stats
))
{
stats
->
rx_bytes
+=
skb
->
len
;
stats
->
tx_bytes
+=
skb
->
len
;
stats
->
rx_packets
++
;
stats
->
tx_packets
++
;
if
(
likely
(
loopback_stats
))
{
get_cpu_ptr
(
loopback_stats
)
->
rx_bytes
+=
skb
->
len
;
get_cpu_ptr
(
loopback_stats
)
->
tx_bytes
+=
skb
->
len
;
get_cpu_ptr
(
loopback_stats
)
->
rx_packets
++
;
get_cpu_ptr
(
loopback_stats
)
->
tx_packets
++
;
put_cpu_ptr
(
loopback_stats
);
}
netif_rx
(
skb
);
...
...
@@ -156,7 +157,28 @@ static int loopback_xmit(struct sk_buff *skb, struct net_device *dev)
static
struct
net_device_stats
*
get_stats
(
struct
net_device
*
dev
)
{
return
(
struct
net_device_stats
*
)
dev
->
priv
;
struct
net_device_stats
*
stats
=
dev
->
priv
;
int
i
;
if
(
!
stats
)
{
return
NULL
;
}
memset
(
stats
,
0
,
sizeof
(
struct
net_device_stats
));
if
(
!
loopback_stats
)
{
return
stats
;
}
for
(
i
=
0
;
i
<
NR_CPUS
;
i
++
)
{
if
(
!
cpu_possible
(
i
))
continue
;
stats
->
rx_bytes
+=
per_cpu_ptr
(
loopback_stats
,
i
)
->
rx_bytes
;
stats
->
tx_bytes
+=
per_cpu_ptr
(
loopback_stats
,
i
)
->
tx_bytes
;
stats
->
rx_packets
+=
per_cpu_ptr
(
loopback_stats
,
i
)
->
rx_packets
;
stats
->
tx_packets
+=
per_cpu_ptr
(
loopback_stats
,
i
)
->
tx_packets
;
}
return
stats
;
}
struct
net_device
loopback_dev
=
{
...
...
@@ -173,7 +195,8 @@ struct net_device loopback_dev = {
.
rebuild_header
=
eth_rebuild_header
,
.
flags
=
IFF_LOOPBACK
,
.
features
=
NETIF_F_SG
|
NETIF_F_FRAGLIST
|
NETIF_F_NO_CSUM
|
NETIF_F_HIGHDMA
,
|
NETIF_F_NO_CSUM
|
NETIF_F_HIGHDMA
|
NETIF_F_LLTX
,
};
/* Setup and register the of the LOOPBACK device. */
...
...
@@ -188,6 +211,8 @@ int __init loopback_init(void)
loopback_dev
.
priv
=
stats
;
loopback_dev
.
get_stats
=
&
get_stats
;
}
loopback_stats
=
alloc_percpu
(
struct
net_device_stats
);
return
register_netdev
(
&
loopback_dev
);
};
...
...
include/linux/netdevice.h
View file @
567f4872
...
...
@@ -405,6 +405,7 @@ struct net_device
#define NETIF_F_HW_VLAN_FILTER 512
/* Receive filtering on VLAN */
#define NETIF_F_VLAN_CHALLENGED 1024
/* Device cannot handle VLAN packets */
#define NETIF_F_TSO 2048
/* Can offload TCP/IP segmentation */
#define NETIF_F_LLTX 4096
/* LockLess TX */
/* Called after device is detached from network. */
void
(
*
uninit
)(
struct
net_device
*
dev
);
...
...
include/net/pkt_sched.h
View file @
567f4872
...
...
@@ -11,6 +11,7 @@
#include <linux/netdevice.h>
#include <linux/types.h>
#include <linux/pkt_sched.h>
#include <linux/rcupdate.h>
#include <net/pkt_cls.h>
#ifdef CONFIG_X86_TSC
...
...
@@ -92,6 +93,7 @@ struct Qdisc
struct
net_device
*
dev
;
struct
tc_stats
stats
;
struct
rcu_head
q_rcu
;
int
(
*
reshape_fail
)(
struct
sk_buff
*
skb
,
struct
Qdisc
*
q
);
/* This field is deprecated, but it is still used by CBQ
...
...
net/core/dev.c
View file @
567f4872
...
...
@@ -107,6 +107,7 @@
#include <linux/module.h>
#include <linux/kallsyms.h>
#include <linux/netpoll.h>
#include <linux/rcupdate.h>
#ifdef CONFIG_NET_RADIO
#include <linux/wireless.h>
/* Note : will define WIRELESS_EXT */
#include <net/iw_handler.h>
...
...
@@ -1305,6 +1306,20 @@ int __skb_linearize(struct sk_buff *skb, int gfp_mask)
return
0
;
}
#define HARD_TX_LOCK_BH(dev, cpu) { \
if ((dev->features & NETIF_F_LLTX) == 0) { \
spin_lock_bh(&dev->xmit_lock); \
dev->xmit_lock_owner = cpu; \
} \
}
#define HARD_TX_UNLOCK_BH(dev) { \
if ((dev->features & NETIF_F_LLTX) == 0) { \
dev->xmit_lock_owner = -1; \
spin_unlock_bh(&dev->xmit_lock); \
} \
}
/**
* dev_queue_xmit - transmit a buffer
* @skb: buffer to transmit
...
...
@@ -1348,18 +1363,35 @@ int dev_queue_xmit(struct sk_buff *skb)
if
(
skb_checksum_help
(
&
skb
,
0
))
goto
out_kfree_skb
;
/* Grab device queue */
spin_lock_bh
(
&
dev
->
queue_lock
);
rcu_read_lock
();
/* Updates of qdisc are serialized by queue_lock.
* The struct Qdisc which is pointed to by qdisc is now a
* rcu structure - it may be accessed without acquiring
* a lock (but the structure may be stale.) The freeing of the
* qdisc will be deferred until it's known that there are no
* more references to it.
*
* If the qdisc has an enqueue function, we still need to
* hold the queue_lock before calling it, since queue_lock
* also serializes access to the device queue.
*/
q
=
dev
->
qdisc
;
smp_read_barrier_depends
();
if
(
q
->
enqueue
)
{
/* Grab device queue */
spin_lock_bh
(
&
dev
->
queue_lock
);
rc
=
q
->
enqueue
(
skb
,
q
);
qdisc_run
(
dev
);
spin_unlock_bh
(
&
dev
->
queue_lock
);
rcu_read_unlock
();
rc
=
rc
==
NET_XMIT_BYPASS
?
NET_XMIT_SUCCESS
:
rc
;
goto
out
;
}
rcu_read_unlock
();
/* The device has no queue. Common case for software devices:
loopback, all the sorts of tunnels...
...
...
@@ -1374,17 +1406,12 @@ int dev_queue_xmit(struct sk_buff *skb)
Either shot noqueue qdisc, it is even simpler 8)
*/
if
(
dev
->
flags
&
IFF_UP
)
{
preempt_disable
();
int
cpu
=
smp_processor_id
();
if
(
dev
->
xmit_lock_owner
!=
cpu
)
{
/*
* The spin_lock effectivly does a preempt lock, but
* we are about to drop that...
*/
preempt_disable
();
spin_unlock
(
&
dev
->
queue_lock
);
spin_lock
(
&
dev
->
xmit_lock
);
dev
->
xmit_lock_owner
=
cpu
;
HARD_TX_LOCK_BH
(
dev
,
cpu
);
preempt_enable
();
if
(
!
netif_queue_stopped
(
dev
))
{
...
...
@@ -1393,18 +1420,17 @@ int dev_queue_xmit(struct sk_buff *skb)
rc
=
0
;
if
(
!
dev
->
hard_start_xmit
(
skb
,
dev
))
{
dev
->
xmit_lock_owner
=
-
1
;
spin_unlock_bh
(
&
dev
->
xmit_lock
);
HARD_TX_UNLOCK_BH
(
dev
);
goto
out
;
}
}
dev
->
xmit_lock_owner
=
-
1
;
spin_unlock_bh
(
&
dev
->
xmit_lock
);
HARD_TX_UNLOCK_BH
(
dev
);
if
(
net_ratelimit
())
printk
(
KERN_CRIT
"Virtual device %s asks to "
"queue packet!
\n
"
,
dev
->
name
);
goto
out_enetdown
;
}
else
{
preempt_enable
();
/* Recursion is detected! It is possible,
* unfortunately */
if
(
net_ratelimit
())
...
...
@@ -1412,7 +1438,6 @@ int dev_queue_xmit(struct sk_buff *skb)
"%s, fix it urgently!
\n
"
,
dev
->
name
);
}
}
spin_unlock_bh
(
&
dev
->
queue_lock
);
out_enetdown:
rc
=
-
ENETDOWN
;
out_kfree_skb:
...
...
net/sched/sch_api.c
View file @
567f4872
...
...
@@ -450,6 +450,9 @@ qdisc_create(struct net_device *dev, u32 handle, struct rtattr **tca, int *errp)
if
(
!
try_module_get
(
ops
->
owner
))
goto
err_out
;
/* enqueue is accessed locklessly - make sure it's visible
* before we set a netdevice's qdisc pointer to sch */
smp_wmb
();
if
(
!
ops
->
init
||
(
err
=
ops
->
init
(
sch
,
tca
[
TCA_OPTIONS
-
1
]))
==
0
)
{
write_lock
(
&
qdisc_tree_lock
);
sch
->
next
=
dev
->
qdisc_list
;
...
...
net/sched/sch_generic.c
View file @
567f4872
...
...
@@ -30,6 +30,7 @@
#include <linux/skbuff.h>
#include <linux/rtnetlink.h>
#include <linux/init.h>
#include <linux/rcupdate.h>
#include <net/sock.h>
#include <net/pkt_sched.h>
...
...
@@ -387,6 +388,9 @@ struct Qdisc * qdisc_create_dflt(struct net_device *dev, struct Qdisc_ops *ops)
sch
->
dev
=
dev
;
sch
->
stats
.
lock
=
&
dev
->
queue_lock
;
atomic_set
(
&
sch
->
refcnt
,
1
);
/* enqueue is accessed locklessly - make sure it's visible
* before we set a netdevice's qdisc pointer to sch */
smp_wmb
();
if
(
!
ops
->
init
||
ops
->
init
(
sch
,
NULL
)
==
0
)
return
sch
;
...
...
@@ -404,18 +408,36 @@ void qdisc_reset(struct Qdisc *qdisc)
ops
->
reset
(
qdisc
);
}
/* this is the rcu callback function to clean up a qdisc when there
* are no further references to it */
static
void
__qdisc_destroy
(
void
*
arg
)
{
struct
Qdisc
*
qdisc
=
(
struct
Qdisc
*
)
arg
;
struct
Qdisc_ops
*
ops
=
qdisc
->
ops
;
#ifdef CONFIG_NET_ESTIMATOR
qdisc_kill_estimator
(
&
qdisc
->
stats
);
#endif
if
(
ops
->
reset
)
ops
->
reset
(
qdisc
);
if
(
ops
->
destroy
)
ops
->
destroy
(
qdisc
);
module_put
(
ops
->
owner
);
if
(
!
(
qdisc
->
flags
&
TCQ_F_BUILTIN
))
kfree
(
qdisc
);
}
/* Under dev->queue_lock and BH! */
void
qdisc_destroy
(
struct
Qdisc
*
qdisc
)
{
struct
Qdisc_ops
*
ops
=
qdisc
->
ops
;
struct
net_device
*
dev
;
struct
net_device
*
dev
=
qdisc
->
dev
;
if
(
!
atomic_dec_and_test
(
&
qdisc
->
refcnt
))
return
;
dev
=
qdisc
->
dev
;
if
(
dev
)
{
struct
Qdisc
*
q
,
**
qp
;
for
(
qp
=
&
qdisc
->
dev
->
qdisc_list
;
(
q
=*
qp
)
!=
NULL
;
qp
=
&
q
->
next
)
{
...
...
@@ -425,16 +447,9 @@ void qdisc_destroy(struct Qdisc *qdisc)
}
}
}
#ifdef CONFIG_NET_ESTIMATOR
qdisc_kill_estimator
(
&
qdisc
->
stats
);
#endif
if
(
ops
->
reset
)
ops
->
reset
(
qdisc
);
if
(
ops
->
destroy
)
ops
->
destroy
(
qdisc
);
module_put
(
ops
->
owner
);
if
(
!
(
qdisc
->
flags
&
TCQ_F_BUILTIN
))
kfree
(
qdisc
);
call_rcu
(
&
qdisc
->
q_rcu
,
__qdisc_destroy
,
qdisc
);
}
...
...
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