From mboxrd@z Thu Jan 1 00:00:00 1970 From: linas@austin.ibm.com (Linas Vepstas) Subject: Re: [PATCH 1/2]: powerpc/cell spidernet bottom half Date: Wed, 16 Aug 2006 16:58:39 -0500 Message-ID: <20060816215839.GK20551@austin.ibm.com> References: <44E34825.2020105@garzik.org> <20060816203043.GJ20551@austin.ibm.com> <44E38157.4070805@garzik.org> <20060816.134640.115912460.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: jeff@garzik.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org, jklewis@us.ibm.com, arnd@arndb.de, Jens.Osterkamp@de.ibm.com, akpm@osdl.org Return-path: Received: from e36.co.us.ibm.com ([32.97.110.154]:10700 "EHLO e36.co.us.ibm.com") by vger.kernel.org with ESMTP id S932275AbWHPV6l (ORCPT ); Wed, 16 Aug 2006 17:58:41 -0400 To: David Miller Content-Disposition: inline In-Reply-To: <20060816.134640.115912460.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, Aug 16, 2006 at 01:46:40PM -0700, David Miller wrote: > From: Jeff Garzik > Date: Wed, 16 Aug 2006 16:34:31 -0400 > > > Linas Vepstas wrote: > > > I was under the impression that NAPI was for the receive side only. > > > > That depends on the driver implementation. > > What Jeff is trying to say is that TX reclaim can occur in > the NAPI poll routine, and in fact this is what the vast > majority of NAPI drivers do. I'll experiment with this. When doing, say, an ftp, there are enough TCP ack packets coming back to have NAPI netdev->poll be called frequently enough? > implied. In fact, I get the impression that spidernet is limited > in some way and that's where all the strange approaches are coming > from :) Hmm. Or maybe I'm just getting old. Once upon a time, low watermarks were considered the "best" way of doing anything; never occurred to me it would be considered "strange". Based on my probably obsolete idea of what constitutes "slick hardware", I was actually impressed by what the spidernet could do. Aside from cleaning up the transmit ring in the receive poll loop, what would be the not-so-strange way of doing things? --linas