These functions compile to 60 bytes of machine code each.
With this .config: http://busybox.net/~vda/kernel_config
there are 617 calls of netif_tx_stop_queue()
and 49 calls of netif_tx_stop_all_queues() in vmlinux.
To fix this, remove WARN_ON in netif_tx_stop_queue()
as suggested by davem, and deinline netif_tx_stop_all_queues().
Change in code size is about 20k:
text data bss dec hex filename
82426986 22255416 20627456 125309858 77813a2 vmlinux.before
82406248 22255416 20627456 125289120 777c2a0 vmlinux
gcc-4.7.2 still creates deinlined version of netif_tx_stop_queue
sometimes:
$ nm --size-sort vmlinux | grep netif_tx_stop_queue | wc -l
190
ffffffff81b558a8 <netif_tx_stop_queue>:
ffffffff81b558a8: 55 push %rbp
ffffffff81b558a9: 48 89 e5 mov %rsp,%rbp
ffffffff81b558ac: f0 80 8f e0 01 00 00 lock orb $0x1,0x1e0(%rdi)
ffffffff81b558b3: 01
ffffffff81b558b4: 5d pop %rbp
ffffffff81b558b5: c3 retq
This needs additional fixing.
Signed-off-by: Denys Vlasenko <[email protected]>
CC: Alexei Starovoitov <[email protected]>
CC: Alexander Duyck <[email protected]>
CC: Joe Perches <[email protected]>
CC: David S. Miller <[email protected]>
CC: Jiri Pirko <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
---
include/linux/netdevice.h | 14 +-------------
net/core/dev.c | 11 +++++++++++
2 files changed, 12 insertions(+), 13 deletions(-)
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index dcf6ec2..536169e 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2548,10 +2548,6 @@ static inline void netif_tx_wake_all_queues(struct net_device *dev)
static inline void netif_tx_stop_queue(struct netdev_queue *dev_queue)
{
- if (WARN_ON(!dev_queue)) {
- pr_info("netif_stop_queue() cannot be called before register_netdev()\n");
- return;
- }
set_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}
@@ -2567,15 +2563,7 @@ static inline void netif_stop_queue(struct net_device *dev)
netif_tx_stop_queue(netdev_get_tx_queue(dev, 0));
}
-static inline void netif_tx_stop_all_queues(struct net_device *dev)
-{
- unsigned int i;
-
- for (i = 0; i < dev->num_tx_queues; i++) {
- struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
- netif_tx_stop_queue(txq);
- }
-}
+void netif_tx_stop_all_queues(struct net_device *dev);
static inline bool netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
{
diff --git a/net/core/dev.c b/net/core/dev.c
index 962ee9d..11e0128 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -6261,6 +6261,17 @@ static int netif_alloc_netdev_queues(struct net_device *dev)
return 0;
}
+void netif_tx_stop_all_queues(struct net_device *dev)
+{
+ unsigned int i;
+
+ for (i = 0; i < dev->num_tx_queues; i++) {
+ struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+ netif_tx_stop_queue(txq);
+ }
+}
+EXPORT_SYMBOL(netif_tx_stop_all_queues);
+
/**
* register_netdevice - register a network device
* @dev: device to register
--
1.8.1.4
On Mon, May 11, 2015 at 09:17:53PM +0200, Denys Vlasenko wrote:
> These functions compile to 60 bytes of machine code each.
> With this .config: http://busybox.net/~vda/kernel_config
> there are 617 calls of netif_tx_stop_queue()
> and 49 calls of netif_tx_stop_all_queues() in vmlinux.
>
> To fix this, remove WARN_ON in netif_tx_stop_queue()
> as suggested by davem, and deinline netif_tx_stop_all_queues().
>
> Change in code size is about 20k:
>
> text data bss dec hex filename
> 82426986 22255416 20627456 125309858 77813a2 vmlinux.before
> 82406248 22255416 20627456 125289120 777c2a0 vmlinux
nice code shrink. Looks good to me.
Acked-by: Alexei Starovoitov <[email protected]>
btw, in the future please say [PATCH net-next] as part of subject
to make it clear what tree this patch is going to.
From: Denys Vlasenko <[email protected]>
Date: Mon, 11 May 2015 21:17:53 +0200
> These functions compile to 60 bytes of machine code each.
> With this .config: http://busybox.net/~vda/kernel_config
> there are 617 calls of netif_tx_stop_queue()
> and 49 calls of netif_tx_stop_all_queues() in vmlinux.
>
> To fix this, remove WARN_ON in netif_tx_stop_queue()
> as suggested by davem, and deinline netif_tx_stop_all_queues().
>
> Change in code size is about 20k:
>
> text data bss dec hex filename
> 82426986 22255416 20627456 125309858 77813a2 vmlinux.before
> 82406248 22255416 20627456 125289120 777c2a0 vmlinux
>
> gcc-4.7.2 still creates deinlined version of netif_tx_stop_queue
> sometimes:
>
> $ nm --size-sort vmlinux | grep netif_tx_stop_queue | wc -l
> 190
>
> ffffffff81b558a8 <netif_tx_stop_queue>:
> ffffffff81b558a8: 55 push %rbp
> ffffffff81b558a9: 48 89 e5 mov %rsp,%rbp
> ffffffff81b558ac: f0 80 8f e0 01 00 00 lock orb $0x1,0x1e0(%rdi)
> ffffffff81b558b3: 01
> ffffffff81b558b4: 5d pop %rbp
> ffffffff81b558b5: c3 retq
>
> This needs additional fixing.
>
> Signed-off-by: Denys Vlasenko <[email protected]>
Applied, thank you.