From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1AC7FECDE30 for ; Wed, 17 Oct 2018 09:11:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1B3821523 for ; Wed, 17 Oct 2018 09:11:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D1B3821523 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727371AbeJQRGm (ORCPT ); Wed, 17 Oct 2018 13:06:42 -0400 Received: from mx2.suse.de ([195.135.220.15]:52596 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726994AbeJQRGm (ORCPT ); Wed, 17 Oct 2018 13:06:42 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id F2BDAAE62; Wed, 17 Oct 2018 09:11:54 +0000 (UTC) Date: Wed, 17 Oct 2018 11:11:54 +0200 From: Michal Hocko To: Alexander Duyck Cc: linux-mm@kvack.org, akpm@linux-foundation.org, pavel.tatashin@microsoft.com, dave.jiang@intel.com, linux-kernel@vger.kernel.org, willy@infradead.org, davem@davemloft.net, yi.z.zhang@linux.intel.com, khalid.aziz@oracle.com, rppt@linux.vnet.ibm.com, vbabka@suse.cz, sparclinux@vger.kernel.org, dan.j.williams@intel.com, ldufour@linux.vnet.ibm.com, mgorman@techsingularity.net, mingo@kernel.org, kirill.shutemov@linux.intel.com Subject: Re: [mm PATCH v3 3/6] mm: Use memblock/zone specific iterator for handling deferred page init Message-ID: <20181017091154.GK18839@dhcp22.suse.cz> References: <20181015202456.2171.88406.stgit@localhost.localdomain> <20181015202709.2171.75580.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181015202709.2171.75580.stgit@localhost.localdomain> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon 15-10-18 13:27:09, Alexander Duyck wrote: > This patch introduces a new iterator for_each_free_mem_pfn_range_in_zone. > > This iterator will take care of making sure a given memory range provided > is in fact contained within a zone. It takes are of all the bounds checking > we were doing in deferred_grow_zone, and deferred_init_memmap. In addition > it should help to speed up the search a bit by iterating until the end of a > range is greater than the start of the zone pfn range, and will exit > completely if the start is beyond the end of the zone. > > This patch adds yet another iterator called > for_each_free_mem_range_in_zone_from and then uses it to support > initializing and freeing pages in groups no larger than MAX_ORDER_NR_PAGES. > By doing this we can greatly improve the cache locality of the pages while > we do several loops over them in the init and freeing process. > > We are able to tighten the loops as a result since we only really need the > checks for first_init_pfn in our first iteration and after that we can > assume that all future values will be greater than this. So I have added a > function called deferred_init_mem_pfn_range_in_zone that primes the > iterators and if it fails we can just exit. Numbers please. Besides that, this adds a lot of code and I am not convinced the result is so much better to justify that. > Signed-off-by: Alexander Duyck > --- > include/linux/memblock.h | 58 +++++++++++++++ > mm/memblock.c | 63 ++++++++++++++++ > mm/page_alloc.c | 176 ++++++++++++++++++++++++++++++++-------------- > 3 files changed, 242 insertions(+), 55 deletions(-) -- Michal Hocko SUSE Labs