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 DEA9EC64EC7 for ; Sun, 26 Feb 2023 02:34:28 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F1BC96B0072; Sat, 25 Feb 2023 21:34:27 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id ECA516B0073; Sat, 25 Feb 2023 21:34:27 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DB8846B0074; Sat, 25 Feb 2023 21:34:27 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id C8C0C6B0072 for ; Sat, 25 Feb 2023 21:34:27 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 9BDF140211 for ; Sun, 26 Feb 2023 02:34:27 +0000 (UTC) X-FDA: 80507874174.03.86E891E Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf08.hostedemail.com (Postfix) with ESMTP id 36E84160003 for ; Sun, 26 Feb 2023 02:34:24 +0000 (UTC) Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=uLTPmin9; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1677378866; 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=04zHyejNXLsg4GD9M3pLHi0M3vC6JyGUgk+eG8MkrHU=; b=x67c0DsOHJHt6TBGRTZj5Cok0ruFkGcPg2RlciIV+DUKkYkLhaxZyJVJSI/IqmoJTUpU4w CPL8PC6uaNAE4KhpBElqJqqSPf9eHAMbhe/8OlJrFS4ompQ2y8CEaIg0M6GLmyekGXzpAH hS5KidLOrewxmwLGZKIxUkwU/Oai5QI= ARC-Authentication-Results: i=1; imf08.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=uLTPmin9; spf=none (imf08.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=none ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1677378866; a=rsa-sha256; cv=none; b=bNbe+pvJb0uXutasR5GupJKFTyjaSfFs2rdmk5ffAwBYQ2vHZHo+a2ceEwqTFp1eqgYQen AmJTYpfm5Gh1fsva9IZ703OYQWuVAr4oF3s0XTdEg8M/rnKpVawANwpr5uDf6M9BISWu5+ A5DNFA+SvEKWw81rprjYkdhf0udyiE4= 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=04zHyejNXLsg4GD9M3pLHi0M3vC6JyGUgk+eG8MkrHU=; b=uLTPmin98Wkui5ff3gTADMACif QzH4UHpO4pUdMqkbMEvHOlGvRmiIcTmzpzfsg47i0xUPLPIAKPD4D9NuMyf/67pWUpNwq+oVLKgaM C7QWqgKXYoETmKtebuzBTLbFddvKKE9F59eZ90IpRWAozmNg9VAokXovHL8six/mO2MBouRRDL4C6 lJtF4EA7J9Yb3ArxQYoCqp+myE8dFpSO3fHCG9dZCiPSJ7lxQdiVcU0brAPNgVkOCW23/R6HDlG2X CBQW04x7j0GcRqjtxz0FLDpSpnTbXTO+kHBHZnF/RFMN6pO+tKAvFrqvadY19f6VUjpaZojOMZRv4 8xhznC1w==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pW6rV-00GZ7M-J8; Sun, 26 Feb 2023 02:34:05 +0000 Date: Sun, 26 Feb 2023 02:34:05 +0000 From: Matthew Wilcox To: Hillf Danton Cc: Yu Zhao , lsf-pc@lists.linux-foundation.org, Linux-MM , Yang Shi , "Yin, Fengwei" , Hugh Dickins , "Kirill A . Shutemov" Subject: Re: [LSF/MM/BPF TOPIC] Flexible orders for anonymous folios Message-ID: References: <20230226013031.3356-1-hdanton@sina.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230226013031.3356-1-hdanton@sina.com> X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 36E84160003 X-Stat-Signature: u7gwbr8fkj9stoe7fnfe8mh3yce19w3x X-HE-Tag: 1677378864-757466 X-HE-Meta: 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 lf+qxYiw BOirWxWbxuPY+Ff57P21rjm6mlMNJMWMvFiXtQzx7CwOpOV/6LaNpIsamKL/jMA9Tk27hzBwyHn8+9WMy96NUelsbybfOOZJvPX19/RjoTq/mrMB28KpwDpLYbA3SqYitJypmS+nx37J0cRiO/Z3qVRoukdpjt2lhEnXhGUagnfIXRPpdXgOrTdgdZVeKDldh/webpwvsu+zH/XnBLtCaqcSRKgRaDaQS8IaS4Dt1FJnEtqRNqyDerCJQIalIDXh/77exWgR1WBC1Z4o= 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 Sun, Feb 26, 2023 at 09:30:31AM +0800, Hillf Danton wrote: > On Wed, Feb 22, 2023 at 04:55:20PM -0700, Yu Zhao wrote: > > Currently anonymous folios only support two orders: 0 and the PMD > > order. Flexible orders for anonymous folios can resist both internal > > or external fragmentations when the PMD order is too underutilized or > > costly to allocate. Flexible orders can also leverage the TLB > > coalescing feature, .e.g., order 3 for AMD and order 4 for ARM CPUs. > > > > Discussion points: > > 1. The page fault path: determining the best order and the fallback policy. > > 2. The reclaim path: detecting the utilization and the splitting policy. > > 3. The refcount and the mapcount models, e.g., reuse the PMD-mapped > > THP model or not. > > 4. The splitting, and the collapsing if needed. > > 5. Other paths: COW, GUP, madvise(), mprotect(), page migration, etc. > > 6. Given the number of TLB is farrr less than the number of pages, > what workload prefers MADV_ORDER6 over MADV_HUGEPAGE for instance? Many. https://lore.kernel.org/linux-mm/Y%2FWRlX+MkmxelNbg@casper.infradead.org/