Re: [PATCH v5] net: ethernet: add driver for Aurora VLSI NB8800 Ethernet controller

[David Miller]

From: Måns Rullgård <mans@xxxxxxxxx>
Date: Wed, 11 Nov 2015 19:35:05 +0000

>> I don't think it's silly at all.
> 
> I'm sure I read somewhere that the time spent spinning on a lock should
> be kept as small as possible.
> 
>> And unless you can measure it making a difference, don't knock the idea.
> 
> I tried using netif_tx_lock() in the IRQ handler instead, and it locked
> up solid.  Clearly that was the wrong thing to do.

Oh that's right, it's a BH lock not an IRQ one.

Yet another argument for doing everything in ->poll(), thus making all
operations outside of NAPI scheduling run in software interrupt
context, and therefore being able to make use of the TXQ lock for
this.
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