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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id CD180C433EF for ; Fri, 22 Jul 2022 19:39:17 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 547968E0001; Fri, 22 Jul 2022 15:39:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4CF4C6B0074; Fri, 22 Jul 2022 15:39:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 349A48E0001; Fri, 22 Jul 2022 15:39:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0012.hostedemail.com [216.40.44.12]) by kanga.kvack.org (Postfix) with ESMTP id 1E8D96B0073 for ; Fri, 22 Jul 2022 15:39:17 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 6FFD780AB0 for ; Fri, 22 Jul 2022 19:39:16 +0000 (UTC) X-FDA: 79715749512.04.A24ADE4 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf30.hostedemail.com (Postfix) with ESMTP id 819ED800A4 for ; Fri, 22 Jul 2022 19:39:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=l+jzRCestlONwS5e/QEwiSBciSF59wpPr9g+H9tlxqk=; b=GxWg9HxXdOAzGz1VFFy97JY9+N UoG5x2Jj9FBg93QRng7y4LoFRhLUWltG9yVqX7WQ44NbLTPaWSUwmd3DN5JLH2xj2W6SjsM3PSIle y2zCuMkTl7tqRbrv+sJ5qxvV1MW2CZIL76aWMXWWEbxxOUxfRt5b+xQOyGuPmoar/2u97oHI1lS+9 PdvKfPuKpAIy4SObx6Z5rCKqLIMQFCt+pa9ItgO1zbz3XiqCvdK5KVMpjcFICcmuR2/H/7nnjsHRc u/XkG6zNQ+PS3SyveLeMjnneObTECH7tbHjr7GUCAm+YmQYNolLJh9LL1Db0Lu6VPgI8EhMRdD65i Igot1B9w==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1oEyUH-00GZ8v-7Q; Fri, 22 Jul 2022 19:39:01 +0000 Date: Fri, 22 Jul 2022 20:39:01 +0100 From: Matthew Wilcox To: "Albert, Des" Cc: Mike Kravetz , "songmuchun@bytedance.com" , "linux-mm@kvack.org" Subject: Re: Additional Huge Pages Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1658518756; a=rsa-sha256; cv=none; b=iz5E5G2NkaT8haGTpiQrz+RIqDjQb9tQx3JDuMt0t1AEvH0XQ6lk9Xt+sgvSEVm5lpjmuF raECmEYUX6jaR1MxpWb9DR9EgPcQDpHYb2biQBWIdpMmlm0slM8yTfNBfcw8SyPCkSwkqc a8WyHFa+tjZaRuRD89kb0moB0IUzHqA= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=GxWg9HxX; dmarc=none; spf=none (imf30.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1658518756; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=l+jzRCestlONwS5e/QEwiSBciSF59wpPr9g+H9tlxqk=; b=ljYY9zpiAzE8fu94axM8oLw80Ld5EmX41sjSytBjYHSy2dUJtcnp3nZwxAvpi714n4Sxjr 8bgmiNQBwJlHaDGOs8kYVs3ynT6wXArZDInY5PB4SJ0EFO4XXV228aZ8o/jW9JuDhjyvHi zVFRqvAhcxyki+BUEo8uoNCHxosZsNU= X-Rspam-User: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 819ED800A4 X-Stat-Signature: 178qub3kb64bnrsar1ri18a6kk6ax76r Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=GxWg9HxX; dmarc=none; spf=none (imf30.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org X-HE-Tag: 1658518755-737583 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 Fri, Jul 22, 2022 at 07:20:51PM +0000, Albert, Des wrote: > This is the first time I have heard of the folio abstraction as the future for memory management. When you mention that future hugetbls work will be based on that concept, it seems unlikely that there would be interest in code that is not consistent with those developments. I also doubt that there would be a justification to 'update' the code to be consistent with future kernel developments. > > I am therefore forming the impression that this idea may not be of interest to the Linux kernel community, however, I do not the detailed technical depth of the development team. > > Do you have some more information about this folio abstraction plan ? Hi Des! I'm the lead on the folio abstraction plan, so hopefully I can be of some help. Folios, like your Cray Hugepages, broaden the supported page sizes. They were originally conceived for relatively small page sizes (eg 16kB-256kB) and have been implemented so far only for the XFS filesystem. Other filesystems are in progress. This is the first hint we've had that people are interested in folio sizes above 2MB. I think the folio work should make supporting this Cray requirement much easier. It's certainly good to know that this is interesting before we do too much work on converting the existing hugetlb code over to folios. Are you able to direct any developers to help us with this? We can definitely work together on this project; we've had a similar collaboration running for a few years now on the Transparent Huge Page side of things.