[PATCH net-next] net: remove dev_pick_tx_cpu_id()

[PATCH net-next] net: remove dev_pick_tx_cpu_id()

[Jakub Kicinski]

dev_pick_tx_cpu_id() has been introduced with two users by
commit a4ea8a3dacc3 ("net: Add generic ndo_select_queue functions").
The use in AF_PACKET has been removed in 2019 by
commit b71b5837f871 ("packet: rework packet_pick_tx_queue() to use common code selection")
The other user was a Netlogic XLP driver, removed in 2021 by
commit 47ac6f567c28 ("staging: Remove Netlogic XLP network driver").

It's relatively unlikely that any modern driver will need an
.ndo_select_queue implementation which picks purely based on CPU ID
and skips XPS, delete dev_pick_tx_cpu_id()

Found by code inspection.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
 include/linux/netdevice.h | 2 --
 net/core/dev.c            | 7 -------
 2 files changed, 9 deletions(-)

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 9168449a51bd..ff184959770b 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -3106,8 +3106,6 @@ void dev_disable_lro(struct net_device *dev);
 int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *newskb);
 u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
 		     struct net_device *sb_dev);
-u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
-		       struct net_device *sb_dev);
 
 int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev);
 int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id);
diff --git a/net/core/dev.c b/net/core/dev.c
index 33629a9d0661..f85fcfb48457 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4249,13 +4249,6 @@ u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
 }
 EXPORT_SYMBOL(dev_pick_tx_zero);
 
-u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
-		       struct net_device *sb_dev)
-{
-	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
-}
-EXPORT_SYMBOL(dev_pick_tx_cpu_id);
-
 u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
 		     struct net_device *sb_dev)
 {
-- 
2.46.0

Re: [PATCH net-next] net: remove dev_pick_tx_cpu_id()

[Eric Dumazet]

On Fri, Sep 6, 2024 at 6:11 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> dev_pick_tx_cpu_id() has been introduced with two users by
> commit a4ea8a3dacc3 ("net: Add generic ndo_select_queue functions").
> The use in AF_PACKET has been removed in 2019 by
> commit b71b5837f871 ("packet: rework packet_pick_tx_queue() to use common code selection")
> The other user was a Netlogic XLP driver, removed in 2021 by
> commit 47ac6f567c28 ("staging: Remove Netlogic XLP network driver").
>
> It's relatively unlikely that any modern driver will need an
> .ndo_select_queue implementation which picks purely based on CPU ID
> and skips XPS, delete dev_pick_tx_cpu_id()
>
> Found by code inspection.
>
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Eric Dumazet <edumazet@google.com>

Re: [PATCH net-next] net: remove dev_pick_tx_cpu_id()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Fri,  6 Sep 2024 09:10:59 -0700 you wrote:
> dev_pick_tx_cpu_id() has been introduced with two users by
> commit a4ea8a3dacc3 ("net: Add generic ndo_select_queue functions").
> The use in AF_PACKET has been removed in 2019 by
> commit b71b5837f871 ("packet: rework packet_pick_tx_queue() to use common code selection")
> The other user was a Netlogic XLP driver, removed in 2021 by
> commit 47ac6f567c28 ("staging: Remove Netlogic XLP network driver").
> 
> [...]

Here is the summary with links:
  - [net-next] net: remove dev_pick_tx_cpu_id()
    https://git.kernel.org/netdev/net-next/c/17245a195df4

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html