From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757258Ab0JUCxt (ORCPT ); Wed, 20 Oct 2010 22:53:49 -0400 Received: from terminus.zytor.com ([198.137.202.10]:42991 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757028Ab0JUCxs (ORCPT ); Wed, 20 Oct 2010 22:53:48 -0400 X-User-Agent: K-9 Mail for Android References: <1287544022.4571.7.camel@sli10-conroe.sh.intel.com> <20101021013833.GA21863@sli10-conroe.sh.intel.com> In-Reply-To: <20101021013833.GA21863@sli10-conroe.sh.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [tip:x86/mm] percpu: Introduce a read-mostly percpu API From: "H. Peter Anvin" Date: Wed, 20 Oct 2010 19:53:17 -0700 To: Shaohua Li CC: "linux-kernel@vger.kernel.org" , "mingo@redhat.com" , "eric.dumazet@gmail.com" , "tglx@linutronix.de" , "hpa@linux.intel.com" Message-ID: <53a2d76e-2737-4e08-b408-2f939e2771e4@email.android.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org I know, but I can't do that immediately. It is an optimizatiin we can do for .38. "Shaohua Li" wrote: >Hi hpa, >On Thu, Oct 21, 2010 at 07:06:59AM +0800, tip-bot for Shaohua Li wrote: >> [ hpa: moved it *after* the page-aligned section, for obvious >> reasons. ] >move it after page-aligned section can't guarantee to avoid cache false >sharing. >we need: >. = ALIGN(CACHE_LINE_SIZE); >*(.data..percpu..readmostly) >. = ALIGN(CACHE_LINE_SIZE); >To make sure before/after readmostly section doesn't share cache line >with >others. The headcache is some arch need L1_CACHE_SIZE and others need >(1 << INTERNODE_CACHE_SHIFT). We need change all ARCHs to make this >happen. -- Sent from my mobile phone. Please pardon any lack of formatting.