From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vitaliy Gusev Subject: Re: [PATCH 3/4] forcedeth: napi schedule lock fix Date: Tue, 27 Jan 2009 19:28:16 +0300 Message-ID: <200901271928.16783.vgusev@openvz.org> References: <4967BBB5.9080803@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Manfred Spraul , Jeff Garzik , Andrew Morton , nedev To: Ayaz Abdulla Return-path: Received: from mailhub.sw.ru ([195.214.232.25]:16218 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755156AbZA0Qh5 (ORCPT ); Tue, 27 Jan 2009 11:37:57 -0500 In-Reply-To: <4967BBB5.9080803@nvidia.com> Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: On 10 January 2009 00:03:49 Ayaz Abdulla wrote: > This patch fixes a potential race condition between scheduling napi and > completing napi poll. The call to netif_rx_schedule should be under > protection of the lock (as is the completion), otherwise, interrupts > could be masked off. Can you explain how this issue or race can occur (interrupts can be masked off) ? netif_rx_schedule() merely mark soft irq as waked on current CPU. So dev->poll will not be called until irq_exit() or local_bh_enable. As nv_nic_irq() is run under interrupt context, so napi poll will be called only during irq_exit. > > Signed-off-by: Ayaz Abdulla > > -- Thank, Vitaliy Gusev