From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH RFC]: napi_struct V4 Date: Wed, 25 Jul 2007 21:55:08 -0400 Message-ID: <46A7FEFC.4040005@pobox.com> References: <20070725.013154.34764933.davem@davemloft.net> <20070725095654.38a10abc@oldman.hamilton.local> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: David Miller , netdev@vger.kernel.org, hadi@cyberus.ca, rusty@rustcorp.com.au To: Stephen Hemminger Return-path: Received: from srv5.dvmed.net ([207.36.208.214]:43230 "EHLO mail.dvmed.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756675AbXGZBzO (ORCPT ); Wed, 25 Jul 2007 21:55:14 -0400 In-Reply-To: <20070725095654.38a10abc@oldman.hamilton.local> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Stephen Hemminger wrote: > The usage of NAPI on 8139cp and 8139too seems dodgy; > these drivers expect this to work: > > local_irq_save(flags); > cpw16_f(IntrMask, cp_intr_mask); > __netif_rx_complete(dev); > local_irq_restore(flags); > > It works on SMP only because if poll races with IRQ, > the IRQ is not masked or cleared so the IRQ will get restarted. Expect? This _does_ work on both UP and SMP. > Better would be to change it to: > spin_lock_irqsave(&cp->lock, flags); > cpw16_f(IntrMask, cp_intr_mask); > __netif_rx_complete(dev); > spin_unlock_irqrestore(&cp->lock, flags); > > Which actually is same code on UP. I'm missing your point? You claim local_irq_save() works only on SMP, then suggest a solution that you agree produces the same result? I don't see any logic to your request, only added overhead for no reason. Jeff