From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ob0-f175.google.com (mail-ob0-f175.google.com [209.85.214.175]) by kanga.kvack.org (Postfix) with ESMTP id 8CF17828E2 for ; Mon, 15 Feb 2016 09:24:23 -0500 (EST) Received: by mail-ob0-f175.google.com with SMTP id jq7so29091448obb.0 for ; Mon, 15 Feb 2016 06:24:23 -0800 (PST) Received: from mail-ob0-x241.google.com (mail-ob0-x241.google.com. [2607:f8b0:4003:c01::241]) by mx.google.com with ESMTPS id rm7si18848265oeb.42.2016.02.15.06.24.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 15 Feb 2016 06:24:22 -0800 (PST) Received: by mail-ob0-x241.google.com with SMTP id kg5so530979obb.3 for ; Mon, 15 Feb 2016 06:24:22 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <56C1A310.9090305@huawei.com> References: <1454566775-30973-1-git-send-email-iamjoonsoo.kim@lge.com> <1454566775-30973-3-git-send-email-iamjoonsoo.kim@lge.com> <20160204164929.a2f12b8a7edcdfa596abd850@linux-foundation.org> <56C0550F.8020402@huawei.com> <20160215024220.GA30918@js1304-P5Q-DELUXE> <56C1A310.9090305@huawei.com> Date: Mon, 15 Feb 2016 23:24:22 +0900 Message-ID: Subject: Re: [PATCH v2 3/3] mm/compaction: speed up pageblock_pfn_to_page() when zone is contiguous From: Joonsoo Kim Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: Xishi Qiu Cc: Joonsoo Kim , zhong jiang , Andrew Morton , Vlastimil Babka , Aaron Lu , Mel Gorman , Rik van Riel , David Rientjes , LKML , Linux Memory Management List 2016-02-15 19:06 GMT+09:00 Xishi Qiu : > On 2016/2/15 10:42, Joonsoo Kim wrote: > >>> >>> I have a question about the zone continuity. because hole exists at >>> arbitrary position in a page block. Therefore, only pageblock_pf_to_page() >>> is insufficiency, whether pageblock aligned pfn or not , the pfn_valid_within() >>> is necessary. >>> >>> eh: 120M-122M is a range of page block, but the 120.5M-121.5M is holes, only by >>> pageblock_pfn_to_page() to conclude in the result is inaccurate >> >> contiguous may be misleading word. It doesn't represent there are no >> hole. It only represents that all pageblocks within zone span belong to >> corresponding zone and validity of all pageblock aligned pfn is >> checked. So, if it is set, we can safely call pfn_to_page() for pageblock >> aligned pfn in that zone without checking pfn_valid(). >> >> Thanks. >> > > Hi Joonsoo, > > So "contiguous" here only means that struct page is exist, and don't care whether > the memory is exist, right? Yes. Thanks. -- 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