Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755284Ab1C2WYu (ORCPT ); Tue, 29 Mar 2011 18:24:50 -0400 Received: from smtp1.linux-foundation.org ([140.211.169.13]:32868 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755161Ab1C2WYs (ORCPT ); Tue, 29 Mar 2011 18:24:48 -0400 Date: Tue, 29 Mar 2011 15:24:34 -0700 From: Andrew Morton To: Shaohua Li Cc: Andi Kleen , linux-mm , lkml , Rik van Riel , Hugh Dickins Subject: Re: [PATCH]mmap: add alignment for some variables Message-Id: <20110329152434.d662706f.akpm@linux-foundation.org> In-Reply-To: <1301360054.3981.31.camel@sli10-conroe> References: <1301277536.3981.27.camel@sli10-conroe> <1301360054.3981.31.camel@sli10-conroe> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 736 Lines: 19 On Tue, 29 Mar 2011 08:54:14 +0800 Shaohua Li wrote: > -struct percpu_counter vm_committed_as; > +struct percpu_counter vm_committed_as ____cacheline_internodealigned_in_smp; Why ____cacheline_internodealigned_in_smp? That's pretty aggressive. afacit the main benefit from this will occur if the read-only vm_committed_as.counters lands in the same cacheline as some write-frequently storage. But that's a complete mad guess and I'd prefer not to have to guess. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/