Received: with ECARTIS (v1.0.0; list netdev); Mon, 31 Jan 2005 17:49:20 -0800 (PST) Received: from ozlabs.org (ozlabs.org [203.10.76.45]) by oss.sgi.com (8.13.0/8.13.0) with ESMTP id j111nFLS021912 for ; Mon, 31 Jan 2005 17:49:16 -0800 Received: by ozlabs.org (Postfix, from userid 1010) id AC9C667A6B; Tue, 1 Feb 2005 12:49:07 +1100 (EST) Date: Tue, 1 Feb 2005 12:43:58 +1100 From: Anton Blanchard To: Scott Feldman Cc: jgarzik@pobox.com, netdev@oss.sgi.com, lunz@falooley.org Subject: Re: [PATCH 2.6] e100: remove reference to NAPI config option Message-ID: <20050201014358.GD15786@krispykreme.ozlabs.ibm.com> References: <1107220952.3366.4.camel@sfeldma-mobl.dsl-verizon.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1107220952.3366.4.camel@sfeldma-mobl.dsl-verizon.net> User-Agent: Mutt/1.5.6+20040907i X-Virus-Scanned: ClamAV 0.80/650/Sun Jan 2 19:00:02 2005 clamav-milter version 0.80j on 127.0.0.1 X-Virus-Status: Clean X-archive-position: 1139 X-ecartis-version: Ecartis v1.0.0 Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com X-original-sender: anton@samba.org Precedence: bulk X-list: netdev Content-Length: 439 Lines: 14 Hi Scott, > e100 is NAPI all the time, so the Kconfig option is wasting space. Speaking of NAPI... We have seen issues with NAPI on ppc64 on various cards in the past. Its possibly due to missing memory barriers; the interrupt and read of the interrupt status provide syncronization with DMA on the non NAPI case. Without this you need to be very careful to order reads (eg between reading the ring status and the packet data). Anton