From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f198.google.com (mail-pf0-f198.google.com [209.85.192.198]) by kanga.kvack.org (Postfix) with ESMTP id 55D586B0038 for ; Mon, 14 Nov 2016 19:33:28 -0500 (EST) Received: by mail-pf0-f198.google.com with SMTP id 17so49633256pfy.2 for ; Mon, 14 Nov 2016 16:33:28 -0800 (PST) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id we6si5734119pab.81.2016.11.14.16.33.27 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 14 Nov 2016 16:33:27 -0800 (PST) Date: Mon, 14 Nov 2016 16:33:26 -0800 From: Andrew Morton 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Vitaly Wool Cc: Linux-MM , linux-kernel@vger.kernel.org, Dan Streetman 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? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org