[PATCH net-next] eth: r8152: try to use a normal budget

[PATCH net-next] eth: r8152: try to use a normal budget

[Jakub Kicinski]

Mario reports that loading r8152 on his system leads to a:

  netif_napi_add_weight() called with weight 256

warning getting printed. We don't have any solid data
on why such high budget was chosen, and it may cause
stalls in processing other softirqs and rt threads.
So try to switch back to the default (64) weight.

If this slows down someone's system we should investigate
which part of stopping starting the NAPI poll in this
driver are expensive.

Reported-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://lore.kernel.org/all/0bfd445a-81f7-f702-08b0-bd5a72095e49@amd.com/
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: hayeswang@realtek.com
CC: bjorn@mork.no
CC: linux-usb@vger.kernel.org
---
 drivers/net/usb/r8152.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index db9897e825b4..bb234cf0cea0 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -9760,8 +9760,7 @@ static int rtl8152_probe(struct usb_interface *intf,
 
 	usb_set_intfdata(intf, tp);
 
-	netif_napi_add_weight(netdev, &tp->napi, r8152_poll,
-			      tp->support_2500full ? 256 : 64);
+	netif_napi_add(netdev, &tp->napi, r8152_poll);
 
 	ret = register_netdev(netdev);
 	if (ret != 0) {
-- 
2.41.0

RE: [PATCH net-next] eth: r8152: try to use a normal budget

[Hayes Wang]

akub Kicinski <kuba@kernel.org>
> Sent: Monday, August 14, 2023 11:35 PM
[...]
> Mario reports that loading r8152 on his system leads to a:
> 
>   netif_napi_add_weight() called with weight 256
> 
> warning getting printed. We don't have any solid data
> on why such high budget was chosen, and it may cause
> stalls in processing other softirqs and rt threads.
> So try to switch back to the default (64) weight.
> 
> If this slows down someone's system we should investigate
> which part of stopping starting the NAPI poll in this
> driver are expensive.
> 
> Reported-by: Mario Limonciello <mario.limonciello@amd.com>
> Link:
> https://lore.kernel.org/all/0bfd445a-81f7-f702-08b0-bd5a72095e49@amd.com
> /
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Acked-by: Hayes Wang <hayeswang@realtek.com>

Best Regards,
Hayes

Re: [PATCH net-next] eth: r8152: try to use a normal budget

[patchwork-bot+netdevbpf]

Hello:

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

On Mon, 14 Aug 2023 08:35:21 -0700 you wrote:
> Mario reports that loading r8152 on his system leads to a:
> 
>   netif_napi_add_weight() called with weight 256
> 
> warning getting printed. We don't have any solid data
> on why such high budget was chosen, and it may cause
> stalls in processing other softirqs and rt threads.
> So try to switch back to the default (64) weight.
> 
> [...]

Here is the summary with links:
  - [net-next] eth: r8152: try to use a normal budget
    https://git.kernel.org/netdev/net-next/c/cf74eb5a5bc8

You are awesome, thank you!
-- 
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