From mboxrd@z Thu Jan 1 00:00:00 1970 From: Anton Blanchard Subject: [patch 06/20] ibmveth: Use lighter weight read memory barrier in ibmveth_poll Date: Mon, 23 Aug 2010 10:09:36 +1000 Message-ID: <20100823001238.849831193@samba.org> References: <20100823000930.546065833@samba.org> Cc: netdev@vger.kernel.org To: brking@linux.vnet.ibm.com, santil@linux.vnet.ibm.com Return-path: Received: from ozlabs.org ([203.10.76.45]:35042 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751371Ab0HWA1x (ORCPT ); Sun, 22 Aug 2010 20:27:53 -0400 Content-Disposition: inline; filename=veth_barriers Sender: netdev-owner@vger.kernel.org List-ID: We want to order the read in ibmveth_rxq_pending_buffer and the read of ibmveth_rxq_buffer_valid which are both cacheable memory. smp_rmb() is good enough for this. Signed-off-by: Anton Blanchard --- Index: net-next-2.6/drivers/net/ibmveth.c =================================================================== --- net-next-2.6.orig/drivers/net/ibmveth.c 2010-08-23 08:52:29.793789816 +1000 +++ net-next-2.6/drivers/net/ibmveth.c 2010-08-23 08:52:30.283755038 +1000 @@ -1010,7 +1010,7 @@ static int ibmveth_poll(struct napi_stru if (!ibmveth_rxq_pending_buffer(adapter)) break; - rmb(); + smp_rmb(); if (!ibmveth_rxq_buffer_valid(adapter)) { wmb(); /* suggested by larson1 */ adapter->rx_invalid_buffer++;