From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965539AbcKOAd2 (ORCPT ); Mon, 14 Nov 2016 19:33:28 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:60638 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755161AbcKOAd1 (ORCPT ); Mon, 14 Nov 2016 19:33:27 -0500 Date: Mon, 14 Nov 2016 16:33:26 -0800 From: Andrew Morton To: Vitaly Wool Cc: Linux-MM , linux-kernel@vger.kernel.org, Dan Streetman Subject: Re: [PATCH] z3fold: discourage use of pages that weren't compacted Message-Id: <20161114163326.b5e991b77745bed6db221bfe@linux-foundation.org> In-Reply-To: <20161111140207.1a5d89af4e0b37e9d23dcd36@gmail.com> References: <20161111140207.1a5d89af4e0b37e9d23dcd36@gmail.com> 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 Fri, 11 Nov 2016 14:02:07 +0100 Vitaly Wool wrote: > If a z3fold page couldn't be compacted, we don't want it to be > used for next object allocation in the first place. It makes more > sense to add it to the end of the relevant unbuddied list. If that > page gets compacted later, it will be added to the beginning of > the list then. > > This simple idea gives 5-7% improvement in randrw fio tests and > about 10% improvement in fio sequential read/write. This patch appears to require "z3fold: use per-page spinlock", and "z3fold: use per-page spinlock" doesn't apply properly. So things are in a bit of a mess. I presently have z3fold-limit-first_num-to-the-actual-range-of-possible-buddy-indexes.patch z3fold-make-pages_nr-atomic.patch z3fold-extend-compaction-function.patch Please take a look, figure out what we should do. Perhaps do it all as a coherent series rather than an interdependent dribble?