Received: with ECARTIS (v1.0.0; list netdev); Tue, 12 Jul 2005 13:29:55 -0700 (PDT) Received: from pentafluge.infradead.org (pentafluge.infradead.org [213.146.154.40]) by oss.sgi.com (8.12.10/8.12.10/SuSE Linux 0.7) with ESMTP id j6CKTgH9028808 for ; Tue, 12 Jul 2005 13:29:51 -0700 Received: from hch by pentafluge.infradead.org with local (Exim 4.52 #1 (Red Hat Linux)) id 1DsRMA-0002rS-Ii; Tue, 12 Jul 2005 21:27:54 +0100 Date: Tue, 12 Jul 2005 21:27:54 +0100 From: Christoph Hellwig To: raghavendra.koushik@neterion.com Cc: jgarzik@pobox.com, netdev@oss.sgi.com, ravinandan.arakali@neterion.com, leonid.grossman@neterion.com, rapuru.sriram@neterion.com Subject: Re: [PATCH 2.6.12.1 5/12] S2io: Performance improvements Message-ID: <20050712202754.GA10768@infradead.org> References: <20050707222741.71C3E89826@linux.site> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050707222741.71C3E89826@linux.site> User-Agent: Mutt/1.4.2.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html X-archive-position: 2718 X-ecartis-version: Ecartis v1.0.0 Sender: netdev-bounce@oss.sgi.com Errors-to: netdev-bounce@oss.sgi.com X-original-sender: hch@infradead.org Precedence: bulk X-list: netdev Content-Length: 570 Lines: 16 > 3. Enable two-buffer mode(for Rx path) automatically for SGI > systems. This improves Rx performance dramatically on > SGI systems. > +/* Enable 2 buffer mode by default for SGI system */ > +#ifdef CONFIG_IA64_SGI_SN2 > +#define CONFIG_2BUFF_MODE > +#endif this enabled it only on kernel that are built to only run on SN2 hardware, which is completely useless in practice. Besides that defining a CONFIG_ symbol from source files is a big no-go. What exactly is the 2buff mode, and more specific what are the downsides of enabling it on non-SGI hardware?