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 230F4C636D6 for ; Fri, 17 Feb 2023 16:54:04 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 89A316B0072; Fri, 17 Feb 2023 11:54:03 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 849FA6B0073; Fri, 17 Feb 2023 11:54:03 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 739086B0074; Fri, 17 Feb 2023 11:54:03 -0500 (EST) 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 6625C6B0072 for ; Fri, 17 Feb 2023 11:54:03 -0500 (EST) Received: from smtpin11.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 4294840302 for ; Fri, 17 Feb 2023 16:54:03 +0000 (UTC) X-FDA: 80477381166.11.BEB4D83 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf25.hostedemail.com (Postfix) with ESMTP id AA570A0009 for ; Fri, 17 Feb 2023 16:54:00 +0000 (UTC) Authentication-Results: imf25.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=evmtxDUd; dmarc=none; spf=none (imf25.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=1676652841; 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=VzEO9ZVN/3nCLhD72Zq+gf6HdzpKHcVdH4QJQxt5wxg=; b=zBC8Pxj/XkZ9iAaa2JxGsqBgmFbejWYt9ZUYxBP7KLfTK2oqFHkNbdlZIdxj4EsDgMFsUr Z59+Sn5qX6QmQuDrdXERwxt13iB+0wlVx6dwcC58ruowKYHLlOStsvpAySFO0OiguwjuEW 9EZZkXM3NL0GsPvNedt3PGg6jQIFM1g= ARC-Authentication-Results: i=1; imf25.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=evmtxDUd; dmarc=none; spf=none (imf25.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1676652841; a=rsa-sha256; cv=none; b=QwffdHIqQn89f6aUI+RveDf9c6F/aPvAuEzm9JxlTJktACmb/OYs9smknopccluHBHPRIA vWE86+OHOKC33GXLj7ELdopiT6xR2x7A9pIwSjxHDg8Azl2MLOqReGPhvn+lvM5DsAlmw7 rPcMBsDoRGkG4gU9Ry1y4KRYdJjz+W4= 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=VzEO9ZVN/3nCLhD72Zq+gf6HdzpKHcVdH4QJQxt5wxg=; b=evmtxDUdlxNXv2gfJsb0gLum9j 4AQoIAkooBWgECMhfQ2GihZ6DDubMNTEzECh0G90rZKlVYwQZKFOdWfqiRxlDObq4I/DU+N9ACzeM T+7FrksZ3+nQqrxhBCIrwTIXlH3LNUEbKYz8CX1L+95HLJWZxmfetA4DmQ79n7UmlADNuo5kgCNfX uAVpPBSy0DmmULmRery3IOxasRPksmpcTlN5RSuuC1iDhchOzpgqPhuGd5RxBFRwV3CcLy7Wss4yF n45/aJg+qmQttsuz3G42g5PtD1w0Q4f+RSvfZYnvBGNz6wUxFOG+8DlFgf4Rmhy9bshsEMQdgNBDC bX6eo2Aw==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1pT3zd-009TIm-PZ; Fri, 17 Feb 2023 16:53:53 +0000 Date: Fri, 17 Feb 2023 16:53:53 +0000 From: Matthew Wilcox To: Aneesh Kumar K V Cc: lsf-pc@lists.linux-foundation.org, Linux MM , Yu Zhao , Dave Hansen , Johannes Weiner Subject: Re: [LSF/MM/BPF TOPIC] Using hardware counters to determine hot/cold pages Message-ID: References: <6bbf2c47-05ab-b78c-3165-2eff18962d6d@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6bbf2c47-05ab-b78c-3165-2eff18962d6d@linux.ibm.com> X-Rspamd-Queue-Id: AA570A0009 X-Rspamd-Server: rspam09 X-Rspam-User: X-Stat-Signature: x5fb8qi3ctdpa7af4boguoz5r8x53wyr X-HE-Tag: 1676652840-645078 X-HE-Meta: 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 G3A3wjeZ 7uukTTXd1V+0aEM5TkgmioEhAJweCir4LwMfvxSCaq1t6shUbTm+8P5oi+nfksyRsGPV2zsAmb4dsPEaJ+T9hpKGSR5RZRnezA4cCEjFtILMgAk0XKnwxt9aKaFi9RXCwQ2VK6YS+GlElTaWyCixdQ9/svA== 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, Feb 17, 2023 at 05:28:09PM +0530, Aneesh Kumar K V wrote: > PowerPC architecture (POWER10) supports a Hot/Cold page tracking > facility that provides access counter and access affinity details at > configurable page size granularity [1]. I have been looking at using Does that advert contain any more information about this feature than: Hot/Cold page tracking | Recording for memory management because I'd like to understand what its limitations are -- can it be a per-VMA option, for example? Or is it set at bootup like CONFIG_PAGE_SIZE? For file-backed memory, the page cache will use variable sized folios, depending on what it determines to be a useful granularity. I'm _expecting_ something of the same sort for anonymous memory, although maybe we'll make that determination on a per-VMA basis and make all folios within a VMA the same size.