From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: [PATCH 12/23] e1000: Maybe stop TX if not enough free descriptors Date: Tue, 19 Sep 2006 13:59:10 -0700 Message-ID: <20060919135910.1afb7f24@localhost.localdomain> References: <20060919172623.4605.56860.stgit@gitlost.site> <20060919172859.4605.60855.stgit@gitlost.site> <45104719.9080708@pobox.com> <20060919125019.316d3790@localhost.localdomain> <451056D2.4080909@pobox.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "Kok, Auke" , netdev@vger.kernel.org, "Brandeburg, Jesse" , "Kok, Auke" , "Ronciak, John" Return-path: Received: from smtp.osdl.org ([65.172.181.4]:57760 "EHLO smtp.osdl.org") by vger.kernel.org with ESMTP id S1752080AbWISU7k (ORCPT ); Tue, 19 Sep 2006 16:59:40 -0400 To: Jeff Garzik In-Reply-To: <451056D2.4080909@pobox.com> Sender: netdev-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Tue, 19 Sep 2006 16:45:06 -0400 Jeff Garzik wrote: > looks OK except for the tasklet, which may starve if the lock is being > held upon entry > > Why would the tasklet starve anymore than NAPI? Worst case, the transmitters fill the ring completely and have to wait for the tasklet to clean up. Maybe it would be better to always to Tx cleanup in tasklet even with NAPI. Then the NAPI poll flow control would be used only for Rx. As it stands, if receiver gets swamped, the poll doesn't get run often, so the transmitter cleanup doesn't get run. A tasklet has the advantage of eliminating the need for adapter->tx_queue_lock as well. Stephen Hemminger