From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 7CFE06B063B for ; Wed, 2 Aug 2017 19:07:20 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id x28so149067wma.7 for ; Wed, 02 Aug 2017 16:07:20 -0700 (PDT) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org. [140.211.169.12]) by mx.google.com with ESMTPS id h65si259325wmh.58.2017.08.02.16.07.18 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 02 Aug 2017 16:07:18 -0700 (PDT) Date: Wed, 2 Aug 2017 16:07:16 -0700 From: Andrew Morton Subject: Re: [PATCH] z3fold: use per-cpu unbuddied lists Message-Id: <20170802160716.f5d1072873799a3a420f6538@linux-foundation.org> In-Reply-To: <20170802122505.e41d5c778a873375bcb0cc19@gmail.com> References: <20170802122505.e41d5c778a873375bcb0cc19@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 , Oleksiy.Avramchenko@sony.com On Wed, 2 Aug 2017 12:25:05 +0200 Vitaly Wool wrote: > z3fold is operating on unbuddied lists in a simple manner: in fact, > it only takes the first entry off the list on a hot path. So if the > z3fold pool is big enough and balanced well enough, considering > only the lists local to the current CPU won't be an issue in any > way, while random I/O performance will go up. Has the performance benefit been measured? It's a large patch. > This patch also introduces two worker threads which: one for async > in-page object layout optimization and one for releasing freed > pages. Why? What are the runtime effects of this change? Does this turn currently-synchronous operations into now-async operations? If so, what are the implications of this if, say, the workqueue doesn't get serviced for a while? etc. Sorry, but I'm not seeing anywhere near enough information and testing results to justify merging such a large and intrusive patch. -- 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