Subject: Re: [PATCH] Reduce locking in TX path of forcedth driver

From: Stephen Hemminger <[email-masked]>
Date: Fri, 21 Dec 2007 18:54:35 -0800

On Fri, 21 Dec 2007 17:41:34 -0800 (PST)
[email-masked] (Tom Herbert) wrote:

> Reduce the amount of locking in the TX path.  Instead of using both netif_tx_lock and dev->priv->lock on transmitting, a single private lock (dev->priv->tx_lock) is used.  This method is similar to that of the e1000 driver, including the logic to stop the queue in the start xmit functions, and the logic to wake the queue in the TX done functions.  We see some performance improvement with this patch.
> 
> Signed-off-by: Tom Herbert <[email-masked]>

>  
> +	spin_lock_init(&np->tx_lock);
> +
> +	dev->features |= NETIF_F_LLTX;
> +

NAK - lockless transmit is not desirable for real devices.

use netif_tx_lock() instead of your private lock

-- 
Stephen Hemminger <[email-masked]>