From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com ([192.55.52.43]:18590 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934574AbdKPWBO (ORCPT ); Thu, 16 Nov 2017 17:01:14 -0500 Date: Thu, 16 Nov 2017 14:01:12 -0800 From: Jesse Brandeburg To: Brian King Cc: , , , , , Michael Ellerman , linuxppc-dev Subject: Re: [Intel-wired-lan] [PATCH 0/7] [RESEND] [net] intel: Use smp_rmb rather than read_barrier_depends Message-ID: <20171116140112.00007c89@intel.com> In-Reply-To: References: <1510846675-15169-1-git-send-email-brking@linux.vnet.ibm.com> <20171116113358.00001d5a@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: stable-owner@vger.kernel.org List-ID: On Thu, 16 Nov 2017 14:03:02 -0600 Brian King wrote: > I did think about changing the powerpc definition of read_barrier_depends, > but after reading up on that barrier, decided it was not the correct barrier > to be used in this context. Here is some good historical background on > read_barrier_depends that I found, along with an example. > > https://lwn.net/Articles/5159/ > > Since there is no data-dependency in the code in question here, I think > the smp_rmb is the proper barrier to use. Hey Brian, thanks for the explanation, I'll agree with you and Alex that the smb_rmb replacement is okay. Does your test still pass without the ->skb NULLs?