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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 5F133C43381 for ; Tue, 12 Jan 2021 13:31:20 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F0BC622285 for ; Tue, 12 Jan 2021 13:31:19 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F0BC622285 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id EBFDC6B0177; Tue, 12 Jan 2021 08:31:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id E70576B0183; Tue, 12 Jan 2021 08:31:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D5E976B0202; Tue, 12 Jan 2021 08:31:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0040.hostedemail.com [216.40.44.40]) by kanga.kvack.org (Postfix) with ESMTP id BC7176B0177 for ; Tue, 12 Jan 2021 08:31:18 -0500 (EST) Received: from smtpin15.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 875E0180AD80F for ; Tue, 12 Jan 2021 13:31:18 +0000 (UTC) X-FDA: 77697209436.15.value42_2608f5a27515 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin15.hostedemail.com (Postfix) with ESMTP id 57AB01814B0C1 for ; Tue, 12 Jan 2021 13:31:18 +0000 (UTC) X-HE-Tag: value42_2608f5a27515 X-Filterd-Recvd-Size: 1934 Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by imf05.hostedemail.com (Postfix) with ESMTP for ; Tue, 12 Jan 2021 13:31:17 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 727A7ACB0; Tue, 12 Jan 2021 13:31:16 +0000 (UTC) Date: Tue, 12 Jan 2021 14:31:14 +0100 From: Oscar Salvador To: David Hildenbrand Cc: akpm@linux-foundation.org, mhocko@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, vbabka@suse.cz, pasha.tatashin@soleen.com Subject: Re: [PATCH 4/5] powerpc/memhotplug: Enable MHP_MEMMAP_ON_MEMORY when supported Message-ID: <20210112133108.GA15667@linux> References: <20201217130758.11565-1-osalvador@suse.de> <20201217130758.11565-5-osalvador@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Mon, Jan 11, 2021 at 05:55:37PM +0100, David Hildenbrand wrote: > On 17.12.20 14:07, Oscar Salvador wrote: > With 16MB LMBs it's quite wasteful - you won't even have a huge page > fitting the the remaining part. > > I do wonder if we want this on powerpc only with a bigger LMB/memory > block size (e.g., 256 MB, which is AFAIK the maximum usually found). Yeah, powerpc is trickier than the others. It is more difficult to take advante of this in this platfowm as depending on the page's size, a larger memory are might have been mapped before, and so, further hot-add operations will be a noop wrt. populating sections, until the range to be added falls in non-mapped area. Nevertheless, I will make this wired to larger memory blocks as you said. -- Oscar Salvador SUSE L3