From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf1-f197.google.com (mail-pf1-f197.google.com [209.85.210.197]) by kanga.kvack.org (Postfix) with ESMTP id 11CC46B0007 for ; Thu, 18 Oct 2018 09:10:51 -0400 (EDT) Received: by mail-pf1-f197.google.com with SMTP id g63-v6so13536823pfc.9 for ; Thu, 18 Oct 2018 06:10:51 -0700 (PDT) Received: from bombadil.infradead.org (bombadil.infradead.org. [2607:7c80:54:e::133]) by mx.google.com with ESMTPS id m63-v6si19761329pld.379.2018.10.18.06.10.50 for (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 18 Oct 2018 06:10:50 -0700 (PDT) Date: Thu, 18 Oct 2018 06:10:46 -0700 From: Matthew Wilcox Subject: Re: [PATCH] mm: get pfn by page_to_pfn() instead of save in page->private Message-ID: <20181018131046.GA32429@bombadil.infradead.org> References: <20181018130429.37837-1-richard.weiyang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181018130429.37837-1-richard.weiyang@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: To: Wei Yang Cc: akpm@linux-foundation.org, mhocko@suse.com, mgorman@techsingularity.net, linux-mm@kvack.org On Thu, Oct 18, 2018 at 09:04:29PM +0800, Wei Yang wrote: > This is not necessary to save the pfn to page->private. > > The pfn could be retrieved by page_to_pfn() directly. > > Signed-off-by: Wei Yang > --- > Maybe I missed some critical reason to save pfn to private. > > Thanks in advance if someone could reveal the special reason. Performance. Did you benchmark this?