From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933192AbcKCWRE (ORCPT ); Thu, 3 Nov 2016 18:17:04 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:58792 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752984AbcKCWRD (ORCPT ); Thu, 3 Nov 2016 18:17:03 -0400 Date: Thu, 3 Nov 2016 15:17:00 -0700 From: Andrew Morton To: Vitaly Wool Cc: Linux-MM , LKML , Dan Streetman Subject: Re: [PATCH] z3fold: make pages_nr atomic Message-Id: <20161103151700.73a98155238acff3f3f98e8b@linux-foundation.org> In-Reply-To: References: <20161103220058.3017148c790b352c0ec521d4@gmail.com> <20161103141404.2bb6b59435e560f0b82c0a18@linux-foundation.org> X-Mailer: Sylpheed 3.4.1 (GTK+ 2.24.23; 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 On Thu, 3 Nov 2016 22:24:07 +0100 Vitaly Wool wrote: > On Thu, Nov 3, 2016 at 10:14 PM, Andrew Morton > wrote: > > On Thu, 3 Nov 2016 22:00:58 +0100 Vitaly Wool wrote: > > > >> This patch converts pages_nr per-pool counter to atomic64_t. > > > > Which is slower. > > > > Presumably there is a reason for making this change. This reason > > should be described in the changelog. > > The reason [which I thought was somewhat obvious :) ] is that there > won't be a need to take a per-pool lock to read or modify that > counter. But the patch didn't change the locking. And as far as I can tell, neither does "z3fold: extend compaction function".